def __init__(self):
try:
# Add missing index on object_id on AccessControl table
creation = BaseDatabaseCreation(connection)
sql = creation.sql_indexes_for_field(
AccessControl,
AccessControl._meta.get_field('object_id'),
no_style(),
)
cursor = connection.cursor()
for s in sql:
logging.debug("running query %s" % s)
cursor.execute(s)
logging.debug("done")
except:
logging.exception("error running query")
#pass
try:
# Remove IP based group members
for group in ExtendedGroup.objects.filter(type=IP_BASED_GROUP):
logging.debug("deleting users from group %s" % group.id)
group.user_set.clear()
logging.debug("done")
except:
logging.exception("error deleting users")
#pass
# Only need to run once
raise MiddlewareNotUsed
def __init__(self):
try:
# Add missing index on object_id on AccessControl table
creation = BaseDatabaseCreation(connection)
sql = creation.sql_indexes_for_field(
AccessControl,
AccessControl._meta.get_field('object_id'),
no_style(),
)
cursor = connection.cursor()
for s in sql:
logging.debug("running query %s" % s)
cursor.execute(s)
logging.debug("done")
except:
logging.exception("error running query")
#pass
try:
# Remove IP based group members
for group in ExtendedGroup.objects.filter(type=IP_BASED_GROUP):
logging.debug("deleting users from group %s" % group.id)
group.user_set.clear()
logging.debug("done")
except:
logging.exception("error deleting users")
#pass
# Only need to run once
raise MiddlewareNotUsed
def __init__(self):
try:
# Add missing index on object_id on AccessControl table
creation = BaseDatabaseCreation(connection)
sql = creation.sql_indexes_for_field(
AccessControl,
AccessControl._meta.get_field('object_id'),
no_style(),
)
cursor = connection.cursor()
for s in sql:
cursor.execute(s)
except:
pass
try:
# Remove IP based group members
for group in ExtendedGroup.objects.filter(type=IP_BASED_GROUP):
group.user_set.all().delete()
except:
pass
# Only need to run once
raise MiddlewareNotUsed
def _digest(self, *args):
"""
Use django.db.backends.creation.BaseDatabaseCreation._digest
to create index name in Django style. An evil hack :(
"""
if not hasattr(self, '_django_db_creation'):
self._django_db_creation = BaseDatabaseCreation(self._get_connection())
return self._django_db_creation._digest(*args)
def run_sql(model): #Runs the SQL to create the table and create indices style=color.no_style() cursor=connection.cursor() obj=BaseDatabaseCreation(connection) statements,pending = obj.sql_create_model(model,style) index_queries=obj.sql_indexes_for_model(model,style) for sql in statements: cursor.execute(sql) for query in index_queries: cursor.execute(query)
def run_sql(model):
#Runs the SQL to create the table and create indices
style = color.no_style()
cursor = connection.cursor()
obj = BaseDatabaseCreation(connection)
statements, pending = obj.sql_create_model(model, style)
index_queries = obj.sql_indexes_for_model(model, style)
for sql in statements:
cursor.execute(sql)
for query in index_queries:
cursor.execute(query)
def _create_index_name(self, model, column_names, suffix=""):
"""
Generates a unique name for an index/unique constraint.
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
return truncate_name(
'%s_%s' % (model._meta.db_table,
BaseDatabaseCreation._digest(column_names[0])),
self.connection.ops.max_name_length())
# Else generate the name for the index using a different algorithm
table_name = model._meta.db_table.replace('"', '').replace('.', '_')
index_unique_name = '_%x' % abs(
hash((table_name, ','.join(column_names))))
# If the index name is too long, truncate it
index_name = (
'%s_%s%s%s' %
(table_name, column_names[0], index_unique_name, suffix)).replace(
'"', '').replace('.', '_')
if len(index_name) > self.connection.features.max_index_name_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(
self.connection.features.max_index_name_length - len(part))],
part)
# It shouldn't start with an underscore (Oracle hates this)
if index_name[0] == "_":
index_name = index_name[1:]
# If it's STILL too long, just hash it down
if len(index_name) > self.connection.features.max_index_name_length:
index_name = hashlib.md5(index_name).hexdigest(
)[:self.connection.features.max_index_name_length]
# It can't start with a number on Oracle, so prepend D if we need to
if index_name[0].isdigit():
index_name = "D%s" % index_name[:-1]
return index_name
def __init__(self, *args, **kwargs):
self.features = BaseDatabaseFeatures()
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = BaseDatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation()
def _create_index_name(self, model, column_names, suffix=""):
"""
Generates a unique name for an index/unique constraint.
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
return truncate_name(
'%s_%s' % (model._meta.db_table, BaseDatabaseCreation._digest(column_names[0])),
self.connection.ops.max_name_length()
)
# Else generate the name for the index using a different algorithm
table_name = model._meta.db_table.replace('"', '').replace('.', '_')
index_unique_name = '_%x' % abs(hash((table_name, ','.join(column_names))))
max_length = self.connection.ops.max_name_length() or 200
# If the index name is too long, truncate it
index_name = ('%s_%s%s%s' % (
table_name, column_names[0], index_unique_name, suffix,
)).replace('"', '').replace('.', '_')
if len(index_name) > max_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(max_length - len(part))], part)
# It shouldn't start with an underscore (Oracle hates this)
if index_name[0] == "_":
index_name = index_name[1:]
# If it's STILL too long, just hash it down
if len(index_name) > max_length:
index_name = hashlib.md5(force_bytes(index_name)).hexdigest()[:max_length]
# It can't start with a number on Oracle, so prepend D if we need to
if index_name[0].isdigit():
index_name = "D%s" % index_name[:-1]
return index_name
def _digest(self, *args):
"""
Use django.db.backends.creation.BaseDatabaseCreation._digest
to create index name in Django style. An evil hack :(
"""
if not hasattr(self, '_django_db_creation'):
self._django_db_creation = BaseDatabaseCreation(self._get_connection())
return self._django_db_creation._digest(*args)
def __init__(self):
try:
# Add missing index on object_id on AccessControl table
creation = BaseDatabaseCreation(connection)
sql = creation.sql_indexes_for_field(
AccessControl,
AccessControl._meta.get_field('object_id'),
no_style(),
)
cursor = connection.cursor()
for s in sql:
cursor.execute(s)
except:
pass
# Only need to run once
raise MiddlewareNotUsed
def __init__(self):
try:
# Add missing index on object_id on AccessControl table
creation = BaseDatabaseCreation(connection)
sql = creation.sql_indexes_for_field(
AccessControl,
AccessControl._meta.get_field('object_id'),
no_style(),
)
cursor = connection.cursor()
for s in sql:
cursor.execute(s)
except:
pass
# Only need to run once
raise MiddlewareNotUsed
def __init__(self, settings_dict, alias, *args, **kwargs):
self.features = BaseDatabaseFeatures(self)
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = BaseDatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
self.settings_dict = settings_dict
self.alias = alias
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = BaseDatabaseFeatures(self)
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = BaseDatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
self.connection = None
self.old_connection = None
self.operators = []
def __init__(self, settings_dict, alias, *args, **kwargs):
self.features = BaseDatabaseFeatures(self)
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = BaseDatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
self.settings_dict = settings_dict
self.alias = alias
self.transaction_state = []
self.savepoint_state = 0
self.dirty = None
def __init__(self, *args, **kwargs):
super(DatabaseWrapper, self).__init__(*args, **kwargs)
self.features = BaseDatabaseFeatures(self)
if VERSION[1] >= 4:
# Django 1.4 and greater
self.ops = DatabaseOperations(self)
else:
self.ops = DatabaseOperations()
self.client = DatabaseClient(self)
self.creation = BaseDatabaseCreation(self)
self.introspection = DatabaseIntrospection(self)
self.validation = BaseDatabaseValidation(self)
self.connection = None
self.old_connection = None
self.operators = []
class DatabaseOperations(object):
"""
Generic SQL implementation of the DatabaseOperations.
Some of this code comes from Django Evolution.
"""
alter_string_set_type = 'ALTER COLUMN %(column)s TYPE %(type)s'
alter_string_set_null = 'ALTER COLUMN %(column)s DROP NOT NULL'
alter_string_drop_null = 'ALTER COLUMN %(column)s SET NOT NULL'
delete_check_sql = 'ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s'
add_column_string = 'ALTER TABLE %s ADD COLUMN %s;'
delete_unique_sql = "ALTER TABLE %s DROP CONSTRAINT %s"
delete_foreign_key_sql = 'ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s'
create_table_sql = 'CREATE TABLE %(table)s (%(columns)s)'
max_index_name_length = 63
drop_index_string = 'DROP INDEX %(index_name)s'
delete_column_string = 'ALTER TABLE %s DROP COLUMN %s CASCADE;'
create_primary_key_string = "ALTER TABLE %(table)s ADD CONSTRAINT %(constraint)s PRIMARY KEY (%(columns)s)"
delete_primary_key_sql = "ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s"
add_check_constraint_fragment = "ADD CONSTRAINT %(constraint)s CHECK (%(check)s)"
rename_table_sql = "ALTER TABLE %s RENAME TO %s;"
backend_name = None
default_schema_name = "public"
# Features
allows_combined_alters = True
supports_foreign_keys = True
has_check_constraints = True
has_booleans = True
raises_default_errors = True
@cached_property
def has_ddl_transactions(self):
"""
Tests the database using feature detection to see if it has
transactional DDL support.
"""
self._possibly_initialise()
connection = self._get_connection()
if hasattr(connection.features, "confirm") and not connection.features._confirmed:
connection.features.confirm()
# Now do the test
if getattr(connection.features, 'supports_transactions', True):
cursor = connection.cursor()
self.start_transaction()
cursor.execute('CREATE TABLE DDL_TRANSACTION_TEST (X INT)')
self.rollback_transaction()
try:
try:
cursor.execute('CREATE TABLE DDL_TRANSACTION_TEST (X INT)')
except DatabaseError:
return False
else:
return True
finally:
cursor.execute('DROP TABLE DDL_TRANSACTION_TEST')
else:
return False
def __init__(self, db_alias):
self.debug = False
self.deferred_sql = []
self.dry_run = False
self.pending_transactions = 0
self.pending_create_signals = []
self.db_alias = db_alias
self._constraint_cache = {}
self._initialised = False
def lookup_constraint(self, db_name, table_name, column_name=None):
""" return a set() of constraints for db_name.table_name.column_name """
def _lookup():
table = self._constraint_cache[db_name][table_name]
if table is INVALID:
raise INVALID
elif column_name is None:
return list(table.items())
else:
return table[column_name]
try:
ret = _lookup()
return ret
except INVALID:
del self._constraint_cache[db_name][table_name]
self._fill_constraint_cache(db_name, table_name)
except KeyError:
if self._is_valid_cache(db_name, table_name):
return []
self._fill_constraint_cache(db_name, table_name)
return self.lookup_constraint(db_name, table_name, column_name)
def _set_cache(self, table_name, column_name=None, value=INVALID):
db_name = self._get_setting('NAME')
try:
if column_name is not None:
self._constraint_cache[db_name][table_name][column_name] = value
else:
self._constraint_cache[db_name][table_name] = value
except (LookupError, TypeError):
pass
def _is_valid_cache(self, db_name, table_name):
# we cache per-table so if the table is there it is valid
try:
return self._constraint_cache[db_name][table_name] is not INVALID
except KeyError:
return False
def _is_multidb(self):
try:
from django.db import connections
connections # Prevents "unused import" warning
except ImportError:
return False
else:
return True
def _get_connection(self):
"""
Returns a django connection for a given DB Alias
"""
if self._is_multidb():
from django.db import connections
return connections[self.db_alias]
else:
from django.db import connection
return connection
def _get_setting(self, setting_name):
"""
Allows code to get a setting (like, for example, STORAGE_ENGINE)
"""
setting_name = setting_name.upper()
connection = self._get_connection()
if self._is_multidb():
# Django 1.2 and above
return connection.settings_dict[setting_name]
else:
# Django 1.1 and below
return getattr(settings, "DATABASE_%s" % setting_name)
def _has_setting(self, setting_name):
"""
Existence-checking version of _get_setting.
"""
try:
self._get_setting(setting_name)
except (KeyError, AttributeError):
return False
else:
return True
def _get_schema_name(self):
try:
return self._get_setting('schema')
except (KeyError, AttributeError):
return self.default_schema_name
def _possibly_initialise(self):
if not self._initialised:
self.connection_init()
self._initialised = True
def connection_init(self):
"""
Run before any SQL to let database-specific config be sent as a command,
e.g. which storage engine or transaction serialisability level.
"""
pass
def quote_name(self, name):
"""
Uses the database backend to quote the given table/column name.
"""
return self._get_connection().ops.quote_name(name)
def _print_sql_error(self, e, sql, params=[]):
print('FATAL ERROR - The following SQL query failed: %s' % sql, file=sys.stderr)
print('The error was: %s' % e, file=sys.stderr)
def execute(self, sql, params=[], print_all_errors=True):
"""
Executes the given SQL statement, with optional parameters.
If the instance's debug attribute is True, prints out what it executes.
"""
self._possibly_initialise()
cursor = self._get_connection().cursor()
if self.debug:
print(" = %s" % sql, params)
if self.dry_run:
return []
get_logger().debug(text_type('execute "%s" with params "%s"' % (sql, params)))
try:
cursor.execute(sql, params)
except DatabaseError as e:
if print_all_errors:
self._print_sql_error(e, sql, params)
raise
try:
return cursor.fetchall()
except BaseException:
return []
def execute_many(
self, sql, regex=r"(?mx) ([^';]* (?:'[^']*'[^';]*)*)", comment_regex=r"(?mx) (?:^\s*$)|(?:--.*$)"):
"""
Takes a SQL file and executes it as many separate statements.
(Some backends, such as Postgres, don't work otherwise.)
"""
# Be warned: This function is full of dark magic. Make sure you really
# know regexes before trying to edit it.
# First, strip comments
sql = "\n".join([x.strip().replace("%", "%%")
for x in re.split(comment_regex, sql) if x.strip()])
# Now execute each statement
for st in re.split(regex, sql)[1:][::2]:
self.execute(st)
def add_deferred_sql(self, sql):
"""
Add a SQL statement to the deferred list, that won't be executed until
this instance's execute_deferred_sql method is run.
"""
self.deferred_sql.append(sql)
def execute_deferred_sql(self):
"""
Executes all deferred SQL, resetting the deferred_sql list
"""
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
def clear_deferred_sql(self):
"""
Resets the deferred_sql list to empty.
"""
self.deferred_sql = []
def clear_run_data(self, pending_creates=None):
"""
Resets variables to how they should be before a run. Used for dry runs.
If you want, pass in an old panding_creates to reset to.
"""
self.clear_deferred_sql()
self.pending_create_signals = pending_creates or []
def get_pending_creates(self):
return self.pending_create_signals
@invalidate_table_constraints
def create_table(self, table_name, fields):
"""
Creates the table 'table_name'. 'fields' is a tuple of fields,
each repsented by a 2-part tuple of field name and a
django.db.models.fields.Field object
"""
if len(table_name) > 63:
print(" ! WARNING: You have a table name longer than 63 characters; this will not fully work on PostgreSQL.")
# avoid default values in CREATE TABLE statements (#925)
for field_name, field in fields:
field._suppress_default = True
columns = [
self.column_sql(table_name, field_name, field)
for field_name, field in fields
]
self.execute(self.create_table_sql % {
"table": self.quote_name(table_name),
"columns": ', '.join([col for col in columns if col]),
})
add_table = alias('create_table') # Alias for consistency's sake
@invalidate_table_constraints
def rename_table(self, old_table_name, table_name):
"""
Renames the table 'old_table_name' to 'table_name'.
"""
if old_table_name == table_name:
# Short-circuit out.
return
params = (self.quote_name(old_table_name), self.quote_name(table_name))
self.execute(self.rename_table_sql % params)
# Invalidate the not-yet-indexed table
self._set_cache(table_name, value=INVALID)
@invalidate_table_constraints
def delete_table(self, table_name, cascade=True):
"""
Deletes the table 'table_name'.
"""
params = (self.quote_name(table_name), )
if cascade:
self.execute('DROP TABLE %s CASCADE;' % params)
else:
self.execute('DROP TABLE %s;' % params)
drop_table = alias('delete_table')
@invalidate_table_constraints
def clear_table(self, table_name):
"""
Deletes all rows from 'table_name'.
"""
params = (self.quote_name(table_name), )
self.execute('DELETE FROM %s;' % params)
@invalidate_table_constraints
def add_column(self, table_name, name, field, keep_default=True):
"""
Adds the column 'name' to the table 'table_name'.
Uses the 'field' paramater, a django.db.models.fields.Field instance,
to generate the necessary sql
@param table_name: The name of the table to add the column to
@param name: The name of the column to add
@param field: The field to use
"""
sql = self.column_sql(table_name, name, field)
if sql:
params = (
self.quote_name(table_name),
sql,
)
sql = self.add_column_string % params
self.execute(sql)
# Now, drop the default if we need to
if field.default is not None:
field.default = NOT_PROVIDED
self.alter_column(
table_name,
name,
field,
explicit_name=False,
ignore_constraints=True)
def _db_type_for_alter_column(self, field):
"""
Returns a field's type suitable for ALTER COLUMN.
By default it just returns field.db_type().
To be overridden by backend specific subclasses
@param field: The field to generate type for
"""
try:
return field.db_type(connection=self._get_connection())
except TypeError:
return field.db_type()
def _alter_add_column_mods(self, field, name, params, sqls):
"""
Subcommand of alter_column that modifies column definitions beyond
the type string -- e.g. adding constraints where they cannot be specified
as part of the type (overrideable)
"""
pass
def _alter_set_defaults(self, field, name, params, sqls):
"Subcommand of alter_column that sets default values (overrideable)"
# Historically, we used to set defaults here.
# But since South 0.8, we don't ever set defaults on alter-column -- we only
# use database-level defaults as scaffolding when adding columns.
# However, we still sometimes need to remove defaults in alter-column.
sqls.append(('ALTER COLUMN %s DROP DEFAULT' % (self.quote_name(name),), []))
def _update_nulls_to_default(self, params, field):
"Subcommand of alter_column that updates nulls to default value (overrideable)"
default = field.get_db_prep_save(field.get_default(), connection=self._get_connection())
self.execute(
'UPDATE %(table_name)s SET %(column)s=%%s WHERE %(column)s IS NULL' %
params, [default])
@invalidate_table_constraints
def alter_column(self, table_name, name, field, explicit_name=True, ignore_constraints=False):
"""
Alters the given column name so it will match the given field.
Note that conversion between the two by the database must be possible.
Will not automatically add _id by default; to have this behavior, pass
explicit_name=False.
@param table_name: The name of the table to add the column to
@param name: The name of the column to alter
@param field: The new field definition to use
"""
if self.dry_run:
if self.debug:
print(' - no dry run output for alter_column() due to dynamic DDL, sorry')
return
# hook for the field to do any resolution prior to it's attributes being queried
if hasattr(field, 'south_init'):
field.south_init()
# Add _id or whatever if we need to
field.set_attributes_from_name(name)
if not explicit_name:
name = field.column
else:
field.column = name
if not ignore_constraints:
# Drop all check constraints. Note that constraints will be added back
# with self.alter_string_set_type and self.alter_string_drop_null.
if self.has_check_constraints:
check_constraints = self._constraints_affecting_columns(table_name, [name], "CHECK")
for constraint in check_constraints:
self.execute(self.delete_check_sql % {
'table': self.quote_name(table_name),
'constraint': self.quote_name(constraint),
})
# Drop all foreign key constraints
try:
self.delete_foreign_key(table_name, name)
except ValueError:
# There weren't any
pass
# First, change the type
params = {
"column": self.quote_name(name),
"type": self._db_type_for_alter_column(field),
"table_name": self.quote_name(table_name)
}
# SQLs is a list of (SQL, values) pairs.
sqls = []
# Only alter the column if it has a type (Geometry ones sometimes don't)
if params["type"] is not None:
sqls.append((self.alter_string_set_type % params, []))
# Add any field- and backend- specific modifications
self._alter_add_column_mods(field, name, params, sqls)
# Next, nullity
if field.null or field.has_default():
sqls.append((self.alter_string_set_null % params, []))
else:
sqls.append((self.alter_string_drop_null % params, []))
# Do defaults
self._alter_set_defaults(field, name, params, sqls)
# Actually change the column (step 1 -- Nullity may need to be fixed)
if self.allows_combined_alters:
sqls, values = zip(*sqls)
self.execute(
"ALTER TABLE %s %s;" % (self.quote_name(table_name), ", ".join(sqls)),
flatten(values),
)
else:
# Some databases don't like more than one alter at once.
for sql, values in sqls:
self.execute("ALTER TABLE %s %s;" % (self.quote_name(table_name), sql), values)
if not field.null and field.has_default():
# Final fixes
self._update_nulls_to_default(params, field)
self.execute(
"ALTER TABLE %s %s;" %
(self.quote_name(table_name),
self.alter_string_drop_null %
params),
[])
if not ignore_constraints:
# Add back FK constraints if needed
if field.rel and self.supports_foreign_keys:
self.execute(
self.foreign_key_sql(
table_name,
field.column,
field.rel.to._meta.db_table,
field.rel.to._meta.get_field(field.rel.field_name).column
)
)
def _fill_constraint_cache(self, db_name, table_name):
schema = self._get_schema_name()
ifsc_tables = ["constraint_column_usage", "key_column_usage"]
self._constraint_cache.setdefault(db_name, {})
self._constraint_cache[db_name][table_name] = {}
for ifsc_table in ifsc_tables:
rows = self.execute("""
SELECT kc.constraint_name, kc.column_name, c.constraint_type
FROM information_schema.%s AS kc
JOIN information_schema.table_constraints AS c ON
kc.table_schema = c.table_schema AND
kc.table_name = c.table_name AND
kc.constraint_name = c.constraint_name
WHERE
kc.table_schema = %%s AND
kc.table_name = %%s
""" % ifsc_table, [schema, table_name])
for constraint, column, kind in rows:
self._constraint_cache[db_name][table_name].setdefault(column, set())
self._constraint_cache[db_name][table_name][column].add((kind, constraint))
return
def _constraints_affecting_columns(self, table_name, columns, type="UNIQUE"):
"""
Gets the names of the constraints affecting the given columns.
If columns is None, returns all constraints of the type on the table.
"""
if self.dry_run:
raise DryRunError("Cannot get constraints for columns.")
if columns is not None:
columns = set(map(lambda s: s.lower(), columns))
db_name = self._get_setting('NAME')
cnames = {}
for col, constraints in self.lookup_constraint(db_name, table_name):
for kind, cname in constraints:
if kind == type:
cnames.setdefault(cname, set())
cnames[cname].add(col.lower())
for cname, cols in cnames.items():
if cols == columns or columns is None:
yield cname
@invalidate_table_constraints
def create_unique(self, table_name, columns):
"""
Creates a UNIQUE constraint on the columns on the given table.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
name = self.create_index_name(table_name, columns, suffix="_uniq")
cols = ", ".join(map(self.quote_name, columns))
self.execute("ALTER TABLE %s ADD CONSTRAINT %s UNIQUE (%s)" % (
self.quote_name(table_name),
self.quote_name(name),
cols,
))
return name
@invalidate_table_constraints
def delete_unique(self, table_name, columns):
"""
Deletes a UNIQUE constraint on precisely the columns on the given table.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
# Dry runs mean we can't do anything.
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_unique_column() due to dynamic DDL, sorry')
return
constraints = list(self._constraints_affecting_columns(table_name, columns))
if not constraints:
raise ValueError(
"Cannot find a UNIQUE constraint on table %s, columns %r" %
(table_name, columns))
for constraint in constraints:
self.execute(self.delete_unique_sql % (
self.quote_name(table_name),
self.quote_name(constraint),
))
def column_sql(self, table_name, field_name, field, tablespace='',
with_name=True, field_prepared=False):
"""
Creates the SQL snippet for a column. Used by add_column and add_table.
"""
# If the field hasn't already been told its attribute name, do so.
if not field_prepared:
field.set_attributes_from_name(field_name)
# hook for the field to do any resolution prior to it's attributes being queried
if hasattr(field, 'south_init'):
field.south_init()
# Possible hook to fiddle with the fields
field = self._field_sanity(field)
try:
sql = field.db_type(connection=self._get_connection())
except TypeError:
sql = field.db_type()
if sql:
# Some callers just want the extended type.
if with_name:
field_output = [self.quote_name(field.column), sql]
else:
field_output = [sql]
field_output.append('%sNULL' % (not field.null and 'NOT ' or ''))
if field.primary_key:
field_output.append('PRIMARY KEY')
elif field.unique:
# Just use UNIQUE (no indexes any more, we have delete_unique)
field_output.append('UNIQUE')
tablespace = field.db_tablespace or tablespace
if tablespace and getattr(self._get_connection().features,
"supports_tablespaces", False) and field.unique:
# We must specify the index tablespace inline, because we
# won't be generating a CREATE INDEX statement for this field.
field_output.append(
self._get_connection().ops.tablespace_sql(
tablespace, inline=True))
sql = ' '.join(field_output)
sqlparams = ()
# if the field is "NOT NULL" and a default value is provided, create the column with it
# this allows the addition of a NOT NULL field to a table with existing rows
if not getattr(field, '_suppress_default', False):
if field.has_default():
default = field.get_default()
# If the default is a callable, then scrap it as we dont want python-based defaults
# written into the database
if callable(default):
get_logger().warn(text_type('discarded column default "%r" on "%s"' % (default, table_name)))
default = None
# If the default is actually None, don't add a default term
if default is not None:
default = field.get_db_prep_save(default, connection=self._get_connection())
default = self._default_value_workaround(default)
# Now do some very cheap quoting. TODO: Redesign return values to avoid
# this.
if isinstance(default, string_types):
default = "'%s'" % default.replace("'", "''")
# Escape any % signs in the output (bug #317)
if isinstance(default, string_types):
default = default.replace("%", "%%")
# Add it in
sql += " DEFAULT %s"
sqlparams = (default)
elif (not field.null and field.blank) or (field.get_default() == ''):
if field.empty_strings_allowed and self._get_connection().features.interprets_empty_strings_as_nulls:
sql += " DEFAULT ''"
# Error here would be nice, but doesn't seem to play fair.
# else:
# raise ValueError("Attempting to add a non null column that isn't character based without an explicit default value.")
if field.rel and self.supports_foreign_keys:
self.add_deferred_sql(
self.foreign_key_sql(
table_name,
field.column,
field.rel.to._meta.db_table,
field.rel.to._meta.get_field(field.rel.field_name).column
)
)
# Things like the contrib.gis module fields have this in 1.1 and below
if hasattr(field, 'post_create_sql'):
for stmt in field.post_create_sql(no_style(), table_name):
self.add_deferred_sql(stmt)
# In 1.2 and above, you have to ask the DatabaseCreation stuff for it.
# This also creates normal indexes in 1.1.
if hasattr(self._get_connection().creation, "sql_indexes_for_field"):
# Make a fake model to pass in, with only db_table
model = self.mock_model("FakeModelForGISCreation", table_name)
for stmt in self._get_connection().creation.sql_indexes_for_field(model, field, no_style()):
self.add_deferred_sql(stmt)
if sql:
return sql % sqlparams
else:
return None
def _field_sanity(self, field):
"""
Placeholder for DBMS-specific field alterations (some combos aren't valid)
"""
return field
def _default_value_workaround(self, value):
"""
DBMS-specific value alterations (this really works around
missing functionality in Django backends)
"""
if isinstance(value, bool) and not self.has_booleans:
return int(value)
else:
return value
def foreign_key_sql(self, from_table_name, from_column_name, to_table_name, to_column_name):
"""
Generates a full SQL statement to add a foreign key constraint
"""
constraint_name = '%s_refs_%s_%s' % (
from_column_name, to_column_name, self._digest(from_table_name, to_table_name))
return 'ALTER TABLE %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % (
self.quote_name(from_table_name),
self.quote_name(self.shorten_name(constraint_name)),
self.quote_name(from_column_name),
self.quote_name(to_table_name),
self.quote_name(to_column_name),
self._get_connection().ops.deferrable_sql() # Django knows this
)
@invalidate_table_constraints
def delete_foreign_key(self, table_name, column):
"""
Drop a foreign key constraint
"""
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_foreign_key() due to dynamic DDL, sorry')
return # We can't look at the DB to get the constraints
constraints = self._find_foreign_constraints(table_name, column)
if not constraints:
raise ValueError(
"Cannot find a FOREIGN KEY constraint on table %s, column %s" %
(table_name, column))
for constraint_name in constraints:
self.execute(self.delete_foreign_key_sql % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(constraint_name),
})
drop_foreign_key = alias('delete_foreign_key')
def _find_foreign_constraints(self, table_name, column_name=None):
constraints = self._constraints_affecting_columns(
table_name, [column_name], "FOREIGN KEY")
primary_key_columns = self._find_primary_key_columns(table_name)
if len(primary_key_columns) > 1:
# Composite primary keys cannot be referenced by a foreign key
return list(constraints)
else:
primary_key_columns.add(column_name)
recursive_constraints = set(self._constraints_affecting_columns(
table_name, primary_key_columns, "FOREIGN KEY"))
return list(recursive_constraints.union(constraints))
def _digest(self, *args):
"""
Use django.db.backends.creation.BaseDatabaseCreation._digest
to create index name in Django style. An evil hack :(
"""
if not hasattr(self, '_django_db_creation'):
self._django_db_creation = BaseDatabaseCreation(self._get_connection())
return self._django_db_creation._digest(*args)
def shorten_name(self, name):
return truncate_name(name, self._get_connection().ops.max_name_length())
def create_index_name(self, table_name, column_names, suffix=""):
"""
Generate a unique name for the index
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
try:
_hash = self._digest([column_names[0]])
except TypeError:
# Django < 1.5 backward compatibility.
_hash = self._digest(column_names[0])
return self.shorten_name(
'%s_%s' % (table_name, _hash),
)
# Else generate the name for the index by South
table_name = table_name.replace('"', '').replace('.', '_')
index_unique_name = '_%x' % abs(hash((table_name, ','.join(column_names))))
# If the index name is too long, truncate it
index_name = (
'%s_%s%s%s' %
(table_name,
column_names[0],
index_unique_name,
suffix)).replace(
'"',
'').replace(
'.',
'_')
if len(index_name) > self.max_index_name_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(self.max_index_name_length - len(part))], part)
return index_name
def create_index_sql(self, table_name, column_names, unique=False, db_tablespace=''):
"""
Generates a create index statement on 'table_name' for a list of 'column_names'
"""
if not column_names:
print("No column names supplied on which to create an index")
return ''
connection = self._get_connection()
if db_tablespace and connection.features.supports_tablespaces:
tablespace_sql = ' ' + connection.ops.tablespace_sql(db_tablespace)
else:
tablespace_sql = ''
index_name = self.create_index_name(table_name, column_names)
return 'CREATE %sINDEX %s ON %s (%s)%s;' % (
unique and 'UNIQUE ' or '',
self.quote_name(index_name),
self.quote_name(table_name),
','.join([self.quote_name(field) for field in column_names]),
tablespace_sql
)
@invalidate_table_constraints
def create_index(self, table_name, column_names, unique=False, db_tablespace=''):
""" Executes a create index statement """
sql = self.create_index_sql(table_name, column_names, unique, db_tablespace)
self.execute(sql)
@invalidate_table_constraints
def delete_index(self, table_name, column_names, db_tablespace=''):
"""
Deletes an index created with create_index.
This is possible using only columns due to the deterministic
index naming function which relies on column names.
"""
if isinstance(column_names, string_types):
column_names = [column_names]
name = self.create_index_name(table_name, column_names)
sql = self.drop_index_string % {
"index_name": self.quote_name(name),
"table_name": self.quote_name(table_name),
}
self.execute(sql)
drop_index = alias('delete_index')
@delete_column_constraints
def delete_column(self, table_name, name):
"""
Deletes the column 'column_name' from the table 'table_name'.
"""
params = (self.quote_name(table_name), self.quote_name(name))
self.execute(self.delete_column_string % params, [])
drop_column = alias('delete_column')
def rename_column(self, table_name, old, new):
"""
Renames the column 'old' from the table 'table_name' to 'new'.
"""
raise NotImplementedError("rename_column has no generic SQL syntax")
@invalidate_table_constraints
def delete_primary_key(self, table_name):
"""
Drops the old primary key.
"""
# Dry runs mean we can't do anything.
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_primary_key() due to dynamic DDL, sorry')
return
constraints = list(
self._constraints_affecting_columns(
table_name, None, type="PRIMARY KEY"))
if not constraints:
raise ValueError("Cannot find a PRIMARY KEY constraint on table %s" % (table_name,))
for constraint in constraints:
self.execute(self.delete_primary_key_sql % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(constraint),
})
drop_primary_key = alias('delete_primary_key')
@invalidate_table_constraints
def create_primary_key(self, table_name, columns):
"""
Creates a new primary key on the specified columns.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
self.execute(self.create_primary_key_string % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(table_name + "_pkey"),
"columns": ", ".join(map(self.quote_name, columns)),
})
def _find_primary_key_columns(self, table_name):
"""
Find all columns of the primary key of the specified table
"""
db_name = self._get_setting('NAME')
primary_key_columns = set()
for col, constraints in self.lookup_constraint(db_name, table_name):
for kind, cname in constraints:
if kind == 'PRIMARY KEY':
primary_key_columns.add(col.lower())
return primary_key_columns
def start_transaction(self):
"""
Makes sure the following commands are inside a transaction.
Must be followed by a (commit|rollback)_transaction call.
"""
if self.dry_run:
self.pending_transactions += 1
if not DJANGO_17:
transaction.commit_unless_managed(using=self.db_alias)
transaction.enter_transaction_management(using=self.db_alias)
transaction.managed(True, using=self.db_alias)
def commit_transaction(self):
"""
Commits the current transaction.
Must be preceded by a start_transaction call.
"""
if self.dry_run:
return
transaction.commit(using=self.db_alias)
if not DJANGO_17:
transaction.leave_transaction_management(using=self.db_alias)
def rollback_transaction(self):
"""
Rolls back the current transaction.
Must be preceded by a start_transaction call.
"""
if self.dry_run:
self.pending_transactions -= 1
transaction.rollback(using=self.db_alias)
if not DJANGO_17:
transaction.leave_transaction_management(using=self.db_alias)
def rollback_transactions_dry_run(self):
"""
Rolls back all pending_transactions during this dry run.
"""
if not self.dry_run:
return
while self.pending_transactions > 0:
self.rollback_transaction()
if not DJANGO_17 and transaction.is_dirty(using=self.db_alias):
# Force an exception, if we're still in a dirty transaction.
# This means we are missing a COMMIT/ROLLBACK.
transaction.leave_transaction_management(using=self.db_alias)
def send_create_signal(self, app_label, model_names):
self.pending_create_signals.append((app_label, model_names))
def send_pending_create_signals(self, verbosity=0, interactive=False):
# Group app_labels together
signals = SortedDict()
for (app_label, model_names) in self.pending_create_signals:
try:
signals[app_label].extend(model_names)
except KeyError:
signals[app_label] = list(model_names)
# Send only one signal per app.
for (app_label, model_names) in signals.items():
self.really_send_create_signal(app_label, list(set(model_names)),
verbosity=verbosity,
interactive=interactive)
self.pending_create_signals = []
def really_send_create_signal(self, app_label, model_names,
verbosity=0, interactive=False):
"""
Sends a post_syncdb signal for the model specified.
If the model is not found (perhaps it's been deleted?),
no signal is sent.
TODO: The behavior of django.contrib.* apps seems flawed in that
they don't respect created_models. Rather, they blindly execute
over all models within the app sending the signal. This is a
patch we should push Django to make For now, this should work.
"""
if self.debug:
print(" - Sending post_syncdb signal for %s: %s" % (app_label, model_names))
app = models.get_app(app_label)
if not app:
return
created_models = []
for model_name in model_names:
try:
model = models.get_model(app_label, model_name)
# Django 1.7 throws LookupError
except LookupError:
pass
else:
if model:
created_models.append(model)
if created_models:
models.signals.post_syncdb.send(
sender=app,
app=app,
created_models=created_models,
verbosity=verbosity,
interactive=interactive,
db=self.db_alias,
)
def mock_model(self, model_name, db_table, db_tablespace='',
pk_field_name='id', pk_field_type=models.AutoField,
pk_field_args=[], pk_field_kwargs={}):
"""
Generates a MockModel class that provides enough information
to be used by a foreign key/many-to-many relationship.
Migrations should prefer to use these rather than actual models
as models could get deleted over time, but these can remain in
migration files forever.
Depreciated.
"""
class MockOptions(object):
def __init__(self):
self.db_table = db_table
self.db_tablespace = db_tablespace or settings.DEFAULT_TABLESPACE
self.object_name = model_name
self.module_name = model_name.lower()
if pk_field_type == models.AutoField:
pk_field_kwargs['primary_key'] = True
self.pk = pk_field_type(*pk_field_args, **pk_field_kwargs)
self.pk.set_attributes_from_name(pk_field_name)
self.abstract = False
def get_field_by_name(self, field_name):
# we only care about the pk field
return (self.pk, self.model, True, False)
def get_field(self, name):
# we only care about the pk field
return self.pk
class MockModel(object):
_meta = None
# We need to return an actual class object here, not an instance
MockModel._meta = MockOptions()
MockModel._meta.model = MockModel
return MockModel
def _db_positive_type_for_alter_column(self, klass, field):
"""
A helper for subclasses overriding _db_type_for_alter_column:
Remove the check constraint from the type string for PositiveInteger
and PositiveSmallInteger fields.
@param klass: The type of the child (required to allow this to be used when it is subclassed)
@param field: The field to generate type for
"""
super_result = super(klass, self)._db_type_for_alter_column(field)
if isinstance(field, (models.PositiveSmallIntegerField, models.PositiveIntegerField)):
return super_result.split(" ", 1)[0]
return super_result
def _alter_add_positive_check(self, klass, field, name, params, sqls):
"""
A helper for subclasses overriding _alter_add_column_mods:
Add a check constraint verifying positivity to PositiveInteger and
PositiveSmallInteger fields.
"""
super(klass, self)._alter_add_column_mods(field, name, params, sqls)
if isinstance(field, (models.PositiveSmallIntegerField, models.PositiveIntegerField)):
uniq_hash = abs(hash(tuple(params.values())))
d = dict(
constraint="CK_%s_PSTV_%s" % (name, hex(uniq_hash)[2:]),
check="%s >= 0" % self.quote_name(name))
sqls.append((self.add_check_constraint_fragment % d, []))
class DatabaseOperations(object):
"""
Generic SQL implementation of the DatabaseOperations.
Some of this code comes from Django Evolution.
"""
alter_string_set_type = 'ALTER COLUMN %(column)s TYPE %(type)s'
alter_string_set_null = 'ALTER COLUMN %(column)s DROP NOT NULL'
alter_string_drop_null = 'ALTER COLUMN %(column)s SET NOT NULL'
delete_check_sql = 'ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s'
add_column_string = 'ALTER TABLE %s ADD COLUMN %s;'
delete_unique_sql = "ALTER TABLE %s DROP CONSTRAINT %s"
delete_foreign_key_sql = 'ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s'
max_index_name_length = 63
drop_index_string = 'DROP INDEX %(index_name)s'
delete_column_string = 'ALTER TABLE %s DROP COLUMN %s CASCADE;'
create_primary_key_string = "ALTER TABLE %(table)s ADD CONSTRAINT %(constraint)s PRIMARY KEY (%(columns)s)"
delete_primary_key_sql = "ALTER TABLE %(table)s DROP CONSTRAINT %(constraint)s"
add_check_constraint_fragment = "ADD CONSTRAINT %(constraint)s CHECK (%(check)s)"
rename_table_sql = "ALTER TABLE %s RENAME TO %s;"
backend_name = None
default_schema_name = "public"
# Features
allows_combined_alters = True
supports_foreign_keys = True
has_check_constraints = True
has_booleans = True
@cached_property
def has_ddl_transactions(self):
"""
Tests the database using feature detection to see if it has
transactional DDL support.
"""
self._possibly_initialise()
connection = self._get_connection()
if hasattr(connection.features, "confirm") and not connection.features._confirmed:
connection.features.confirm()
# Django 1.3's MySQLdb backend doesn't raise DatabaseError
exceptions = (DatabaseError, )
try:
from MySQLdb import OperationalError
exceptions += (OperationalError, )
except ImportError:
pass
# Now do the test
if getattr(connection.features, 'supports_transactions', True):
cursor = connection.cursor()
self.start_transaction()
cursor.execute('CREATE TABLE DDL_TRANSACTION_TEST (X INT)')
self.rollback_transaction()
try:
try:
cursor.execute('CREATE TABLE DDL_TRANSACTION_TEST (X INT)')
except exceptions:
return False
else:
return True
finally:
cursor.execute('DROP TABLE DDL_TRANSACTION_TEST')
else:
return False
def __init__(self, db_alias):
self.debug = False
self.deferred_sql = []
self.dry_run = False
self.pending_transactions = 0
self.pending_create_signals = []
self.db_alias = db_alias
self._constraint_cache = {}
self._initialised = False
def lookup_constraint(self, db_name, table_name, column_name=None):
""" return a set() of constraints for db_name.table_name.column_name """
def _lookup():
table = self._constraint_cache[db_name][table_name]
if table is INVALID:
raise INVALID
elif column_name is None:
return list(table.items())
else:
return table[column_name]
try:
ret = _lookup()
return ret
except INVALID:
del self._constraint_cache[db_name][table_name]
self._fill_constraint_cache(db_name, table_name)
except KeyError:
if self._is_valid_cache(db_name, table_name):
return []
self._fill_constraint_cache(db_name, table_name)
return self.lookup_constraint(db_name, table_name, column_name)
def _set_cache(self, table_name, column_name=None, value=INVALID):
db_name = self._get_setting('NAME')
try:
if column_name is not None:
self._constraint_cache[db_name][table_name][column_name] = value
else:
self._constraint_cache[db_name][table_name] = value
except (LookupError, TypeError):
pass
def _is_valid_cache(self, db_name, table_name):
# we cache per-table so if the table is there it is valid
try:
return self._constraint_cache[db_name][table_name] is not INVALID
except KeyError:
return False
def _is_multidb(self):
try:
from django.db import connections
connections # Prevents "unused import" warning
except ImportError:
return False
else:
return True
def _get_connection(self):
"""
Returns a django connection for a given DB Alias
"""
if self._is_multidb():
from django.db import connections
return connections[self.db_alias]
else:
from django.db import connection
return connection
def _get_setting(self, setting_name):
"""
Allows code to get a setting (like, for example, STORAGE_ENGINE)
"""
setting_name = setting_name.upper()
connection = self._get_connection()
if self._is_multidb():
# Django 1.2 and above
return connection.settings_dict[setting_name]
else:
# Django 1.1 and below
return getattr(settings, "DATABASE_%s" % setting_name)
def _has_setting(self, setting_name):
"""
Existence-checking version of _get_setting.
"""
try:
self._get_setting(setting_name)
except (KeyError, AttributeError):
return False
else:
return True
def _get_schema_name(self):
try:
return self._get_setting('schema')
except (KeyError, AttributeError):
return self.default_schema_name
def _possibly_initialise(self):
if not self._initialised:
self.connection_init()
self._initialised = True
def connection_init(self):
"""
Run before any SQL to let database-specific config be sent as a command,
e.g. which storage engine (MySQL) or transaction serialisability level.
"""
pass
def quote_name(self, name):
"""
Uses the database backend to quote the given table/column name.
"""
return self._get_connection().ops.quote_name(name)
def _print_sql_error(self, e, sql, params=[]):
print('FATAL ERROR - The following SQL query failed: %s' % sql, file=sys.stderr)
print('The error was: %s' % e, file=sys.stderr)
def execute(self, sql, params=[], print_all_errors=True):
"""
Executes the given SQL statement, with optional parameters.
If the instance's debug attribute is True, prints out what it executes.
"""
self._possibly_initialise()
cursor = self._get_connection().cursor()
if self.debug:
print(" = %s" % sql, params)
if self.dry_run:
return []
get_logger().debug(text_type('execute "%s" with params "%s"' % (sql, params)))
try:
cursor.execute(sql, params)
except DatabaseError as e:
if print_all_errors:
self._print_sql_error(e, sql, params)
raise
try:
return cursor.fetchall()
except:
return []
def execute_many(self, sql, regex=r"(?mx) ([^';]* (?:'[^']*'[^';]*)*)", comment_regex=r"(?mx) (?:^\s*$)|(?:--.*$)"):
"""
Takes a SQL file and executes it as many separate statements.
(Some backends, such as Postgres, don't work otherwise.)
"""
# Be warned: This function is full of dark magic. Make sure you really
# know regexes before trying to edit it.
# First, strip comments
sql = "\n".join([x.strip().replace("%", "%%") for x in re.split(comment_regex, sql) if x.strip()])
# Now execute each statement
for st in re.split(regex, sql)[1:][::2]:
self.execute(st)
def add_deferred_sql(self, sql):
"""
Add a SQL statement to the deferred list, that won't be executed until
this instance's execute_deferred_sql method is run.
"""
self.deferred_sql.append(sql)
def execute_deferred_sql(self):
"""
Executes all deferred SQL, resetting the deferred_sql list
"""
for sql in self.deferred_sql:
self.execute(sql)
self.deferred_sql = []
def clear_deferred_sql(self):
"""
Resets the deferred_sql list to empty.
"""
self.deferred_sql = []
def clear_run_data(self, pending_creates = None):
"""
Resets variables to how they should be before a run. Used for dry runs.
If you want, pass in an old panding_creates to reset to.
"""
self.clear_deferred_sql()
self.pending_create_signals = pending_creates or []
def get_pending_creates(self):
return self.pending_create_signals
@invalidate_table_constraints
def create_table(self, table_name, fields):
"""
Creates the table 'table_name'. 'fields' is a tuple of fields,
each repsented by a 2-part tuple of field name and a
django.db.models.fields.Field object
"""
if len(table_name) > 63:
print(" ! WARNING: You have a table name longer than 63 characters; this will not fully work on PostgreSQL or MySQL.")
# avoid default values in CREATE TABLE statements (#925)
for field_name, field in fields:
field._suppress_default = True
columns = [
self.column_sql(table_name, field_name, field)
for field_name, field in fields
]
self.execute('CREATE TABLE %s (%s);' % (
self.quote_name(table_name),
', '.join([col for col in columns if col]),
))
add_table = alias('create_table') # Alias for consistency's sake
@invalidate_table_constraints
def rename_table(self, old_table_name, table_name):
"""
Renames the table 'old_table_name' to 'table_name'.
"""
if old_table_name == table_name:
# Short-circuit out.
return
params = (self.quote_name(old_table_name), self.quote_name(table_name))
self.execute(self.rename_table_sql % params)
# Invalidate the not-yet-indexed table
self._set_cache(table_name, value=INVALID)
@invalidate_table_constraints
def delete_table(self, table_name, cascade=True):
"""
Deletes the table 'table_name'.
"""
params = (self.quote_name(table_name), )
if cascade:
self.execute('DROP TABLE %s CASCADE;' % params)
else:
self.execute('DROP TABLE %s;' % params)
drop_table = alias('delete_table')
@invalidate_table_constraints
def clear_table(self, table_name):
"""
Deletes all rows from 'table_name'.
"""
params = (self.quote_name(table_name), )
self.execute('DELETE FROM %s;' % params)
@invalidate_table_constraints
def add_column(self, table_name, name, field, keep_default=True):
"""
Adds the column 'name' to the table 'table_name'.
Uses the 'field' paramater, a django.db.models.fields.Field instance,
to generate the necessary sql
@param table_name: The name of the table to add the column to
@param name: The name of the column to add
@param field: The field to use
"""
sql = self.column_sql(table_name, name, field)
if sql:
params = (
self.quote_name(table_name),
sql,
)
sql = self.add_column_string % params
self.execute(sql)
# Now, drop the default if we need to
if not keep_default and field.default is not None:
field.default = NOT_PROVIDED
self.alter_column(table_name, name, field, explicit_name=False, ignore_constraints=True)
def _db_type_for_alter_column(self, field):
"""
Returns a field's type suitable for ALTER COLUMN.
By default it just returns field.db_type().
To be overriden by backend specific subclasses
@param field: The field to generate type for
"""
try:
return field.db_type(connection=self._get_connection())
except TypeError:
return field.db_type()
def _alter_add_column_mods(self, field, name, params, sqls):
"""
Subcommand of alter_column that modifies column definitions beyond
the type string -- e.g. adding constraints where they cannot be specified
as part of the type (overrideable)
"""
pass
def _alter_set_defaults(self, field, name, params, sqls):
"Subcommand of alter_column that sets default values (overrideable)"
# Next, set any default
if not field.null and field.has_default():
default = field.get_default()
sqls.append(('ALTER COLUMN %s SET DEFAULT %%s ' % (self.quote_name(name),), [default]))
else:
sqls.append(('ALTER COLUMN %s DROP DEFAULT' % (self.quote_name(name),), []))
def _update_nulls_to_default(self, params, field):
"Subcommand of alter_column that updates nulls to default value (overrideable)"
default = field.get_default()
self.execute('UPDATE %(table_name)s SET %(column)s=%%s WHERE %(column)s IS NULL' % params, [default])
@invalidate_table_constraints
def alter_column(self, table_name, name, field, explicit_name=True, ignore_constraints=False):
"""
Alters the given column name so it will match the given field.
Note that conversion between the two by the database must be possible.
Will not automatically add _id by default; to have this behavour, pass
explicit_name=False.
@param table_name: The name of the table to add the column to
@param name: The name of the column to alter
@param field: The new field definition to use
"""
if self.dry_run:
if self.debug:
print(' - no dry run output for alter_column() due to dynamic DDL, sorry')
return
# hook for the field to do any resolution prior to it's attributes being queried
if hasattr(field, 'south_init'):
field.south_init()
# Add _id or whatever if we need to
field.set_attributes_from_name(name)
if not explicit_name:
name = field.column
else:
field.column = name
if not ignore_constraints:
# Drop all check constraints. Note that constraints will be added back
# with self.alter_string_set_type and self.alter_string_drop_null.
if self.has_check_constraints:
check_constraints = self._constraints_affecting_columns(table_name, [name], "CHECK")
for constraint in check_constraints:
self.execute(self.delete_check_sql % {
'table': self.quote_name(table_name),
'constraint': self.quote_name(constraint),
})
# Drop all foreign key constraints
try:
self.delete_foreign_key(table_name, name)
except ValueError:
# There weren't any
pass
# First, change the type
params = {
"column": self.quote_name(name),
"type": self._db_type_for_alter_column(field),
"table_name": self.quote_name(table_name)
}
# SQLs is a list of (SQL, values) pairs.
sqls = []
# Only alter the column if it has a type (Geometry ones sometimes don't)
if params["type"] is not None:
sqls.append((self.alter_string_set_type % params, []))
# Add any field- and backend- specific modifications
self._alter_add_column_mods(field, name, params, sqls)
# Next, nullity
if field.null or field.has_default():
sqls.append((self.alter_string_set_null % params, []))
else:
sqls.append((self.alter_string_drop_null % params, []))
# Actually change the column (step 1 -- Nullity may need to be fixed)
if self.allows_combined_alters:
sqls, values = zip(*sqls)
self.execute(
"ALTER TABLE %s %s;" % (self.quote_name(table_name), ", ".join(sqls)),
flatten(values),
)
else:
# Databases like e.g. MySQL don't like more than one alter at once.
for sql, values in sqls:
self.execute("ALTER TABLE %s %s;" % (self.quote_name(table_name), sql), values)
if not field.null and field.has_default():
# Final fixes
self._update_nulls_to_default(params, field)
self.execute("ALTER TABLE %s %s;" % (self.quote_name(table_name), self.alter_string_drop_null % params), [])
if not ignore_constraints:
# Add back FK constraints if needed
if field.rel and self.supports_foreign_keys:
self.execute(
self.foreign_key_sql(
table_name,
field.column,
field.rel.to._meta.db_table,
field.rel.to._meta.get_field(field.rel.field_name).column
)
)
def _fill_constraint_cache(self, db_name, table_name):
schema = self._get_schema_name()
ifsc_tables = ["constraint_column_usage", "key_column_usage"]
self._constraint_cache.setdefault(db_name, {})
self._constraint_cache[db_name][table_name] = {}
for ifsc_table in ifsc_tables:
rows = self.execute("""
SELECT kc.constraint_name, kc.column_name, c.constraint_type
FROM information_schema.%s AS kc
JOIN information_schema.table_constraints AS c ON
kc.table_schema = c.table_schema AND
kc.table_name = c.table_name AND
kc.constraint_name = c.constraint_name
WHERE
kc.table_schema = %%s AND
kc.table_name = %%s
""" % ifsc_table, [schema, table_name])
for constraint, column, kind in rows:
self._constraint_cache[db_name][table_name].setdefault(column, set())
self._constraint_cache[db_name][table_name][column].add((kind, constraint))
return
def _constraints_affecting_columns(self, table_name, columns, type="UNIQUE"):
"""
Gets the names of the constraints affecting the given columns.
If columns is None, returns all constraints of the type on the table.
"""
if self.dry_run:
raise DryRunError("Cannot get constraints for columns.")
if columns is not None:
columns = set(map(lambda s: s.lower(), columns))
db_name = self._get_setting('NAME')
cnames = {}
for col, constraints in self.lookup_constraint(db_name, table_name):
for kind, cname in constraints:
if kind == type:
cnames.setdefault(cname, set())
cnames[cname].add(col.lower())
for cname, cols in cnames.items():
if cols == columns or columns is None:
yield cname
@invalidate_table_constraints
def create_unique(self, table_name, columns):
"""
Creates a UNIQUE constraint on the columns on the given table.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
name = self.create_index_name(table_name, columns, suffix="_uniq")
cols = ", ".join(map(self.quote_name, columns))
self.execute("ALTER TABLE %s ADD CONSTRAINT %s UNIQUE (%s)" % (
self.quote_name(table_name),
self.quote_name(name),
cols,
))
return name
@invalidate_table_constraints
def delete_unique(self, table_name, columns):
"""
Deletes a UNIQUE constraint on precisely the columns on the given table.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
# Dry runs mean we can't do anything.
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_unique_column() due to dynamic DDL, sorry')
return
constraints = list(self._constraints_affecting_columns(table_name, columns))
if not constraints:
raise ValueError("Cannot find a UNIQUE constraint on table %s, columns %r" % (table_name, columns))
for constraint in constraints:
self.execute(self.delete_unique_sql % (
self.quote_name(table_name),
self.quote_name(constraint),
))
def column_sql(self, table_name, field_name, field, tablespace='', with_name=True, field_prepared=False):
"""
Creates the SQL snippet for a column. Used by add_column and add_table.
"""
# If the field hasn't already been told its attribute name, do so.
if not field_prepared:
field.set_attributes_from_name(field_name)
# hook for the field to do any resolution prior to it's attributes being queried
if hasattr(field, 'south_init'):
field.south_init()
# Possible hook to fiddle with the fields (e.g. defaults & TEXT on MySQL)
field = self._field_sanity(field)
try:
sql = field.db_type(connection=self._get_connection())
except TypeError:
sql = field.db_type()
if sql:
# Some callers, like the sqlite stuff, just want the extended type.
if with_name:
field_output = [self.quote_name(field.column), sql]
else:
field_output = [sql]
field_output.append('%sNULL' % (not field.null and 'NOT ' or ''))
if field.primary_key:
field_output.append('PRIMARY KEY')
elif field.unique:
# Just use UNIQUE (no indexes any more, we have delete_unique)
field_output.append('UNIQUE')
tablespace = field.db_tablespace or tablespace
if tablespace and getattr(self._get_connection().features, "supports_tablespaces", False) and field.unique:
# We must specify the index tablespace inline, because we
# won't be generating a CREATE INDEX statement for this field.
field_output.append(self._get_connection().ops.tablespace_sql(tablespace, inline=True))
sql = ' '.join(field_output)
sqlparams = ()
# if the field is "NOT NULL" and a default value is provided, create the column with it
# this allows the addition of a NOT NULL field to a table with existing rows
if not getattr(field, '_suppress_default', False):
if field.has_default():
default = field.get_default()
# If the default is actually None, don't add a default term
if default is not None:
# If the default is a callable, then call it!
if callable(default):
default = default()
default = field.get_db_prep_save(default, connection=self._get_connection())
default = self._default_value_workaround(default)
# Now do some very cheap quoting. TODO: Redesign return values to avoid this.
if isinstance(default, string_types):
default = "'%s'" % default.replace("'", "''")
# Escape any % signs in the output (bug #317)
if isinstance(default, string_types):
default = default.replace("%", "%%")
# Add it in
sql += " DEFAULT %s"
sqlparams = (default)
elif (not field.null and field.blank) or (field.get_default() == ''):
if field.empty_strings_allowed and self._get_connection().features.interprets_empty_strings_as_nulls:
sql += " DEFAULT ''"
# Error here would be nice, but doesn't seem to play fair.
#else:
# raise ValueError("Attempting to add a non null column that isn't character based without an explicit default value.")
if field.rel and self.supports_foreign_keys:
self.add_deferred_sql(
self.foreign_key_sql(
table_name,
field.column,
field.rel.to._meta.db_table,
field.rel.to._meta.get_field(field.rel.field_name).column
)
)
# Things like the contrib.gis module fields have this in 1.1 and below
if hasattr(field, 'post_create_sql'):
for stmt in field.post_create_sql(no_style(), table_name):
self.add_deferred_sql(stmt)
# In 1.2 and above, you have to ask the DatabaseCreation stuff for it.
# This also creates normal indexes in 1.1.
if hasattr(self._get_connection().creation, "sql_indexes_for_field"):
# Make a fake model to pass in, with only db_table
model = self.mock_model("FakeModelForGISCreation", table_name)
for stmt in self._get_connection().creation.sql_indexes_for_field(model, field, no_style()):
self.add_deferred_sql(stmt)
if sql:
return sql % sqlparams
else:
return None
def _field_sanity(self, field):
"""
Placeholder for DBMS-specific field alterations (some combos aren't valid,
e.g. DEFAULT and TEXT on MySQL)
"""
return field
def _default_value_workaround(self, value):
"""
DBMS-specific value alterations (this really works around
missing functionality in Django backends)
"""
if isinstance(value, bool) and not self.has_booleans:
return int(value)
else:
return value
def foreign_key_sql(self, from_table_name, from_column_name, to_table_name, to_column_name):
"""
Generates a full SQL statement to add a foreign key constraint
"""
constraint_name = '%s_refs_%s_%s' % (from_column_name, to_column_name, self._digest(from_table_name, to_table_name))
return 'ALTER TABLE %s ADD CONSTRAINT %s FOREIGN KEY (%s) REFERENCES %s (%s)%s;' % (
self.quote_name(from_table_name),
self.quote_name(self.shorten_name(constraint_name)),
self.quote_name(from_column_name),
self.quote_name(to_table_name),
self.quote_name(to_column_name),
self._get_connection().ops.deferrable_sql() # Django knows this
)
@invalidate_table_constraints
def delete_foreign_key(self, table_name, column):
"""
Drop a foreign key constraint
"""
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_foreign_key() due to dynamic DDL, sorry')
return # We can't look at the DB to get the constraints
constraints = self._find_foreign_constraints(table_name, column)
if not constraints:
raise ValueError("Cannot find a FOREIGN KEY constraint on table %s, column %s" % (table_name, column))
for constraint_name in constraints:
self.execute(self.delete_foreign_key_sql % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(constraint_name),
})
drop_foreign_key = alias('delete_foreign_key')
def _find_foreign_constraints(self, table_name, column_name=None):
constraints = self._constraints_affecting_columns(
table_name, [column_name], "FOREIGN KEY")
primary_key_columns = self._find_primary_key_columns(table_name)
if len(primary_key_columns) > 1:
# Composite primary keys cannot be referenced by a foreign key
return list(constraints)
else:
primary_key_columns.add(column_name)
recursive_constraints = set(self._constraints_affecting_columns(
table_name, primary_key_columns, "FOREIGN KEY"))
return list(recursive_constraints.union(constraints))
def _digest(self, *args):
"""
Use django.db.backends.creation.BaseDatabaseCreation._digest
to create index name in Django style. An evil hack :(
"""
if not hasattr(self, '_django_db_creation'):
self._django_db_creation = BaseDatabaseCreation(self._get_connection())
return self._django_db_creation._digest(*args)
def shorten_name(self, name):
return truncate_name(name, self._get_connection().ops.max_name_length())
def create_index_name(self, table_name, column_names, suffix=""):
"""
Generate a unique name for the index
"""
# If there is just one column in the index, use a default algorithm from Django
if len(column_names) == 1 and not suffix:
return self.shorten_name(
'%s_%s' % (table_name, self._digest(column_names[0]))
)
# Else generate the name for the index by South
table_name = table_name.replace('"', '').replace('.', '_')
index_unique_name = '_%x' % abs(hash((table_name, ','.join(column_names))))
# If the index name is too long, truncate it
index_name = ('%s_%s%s%s' % (table_name, column_names[0], index_unique_name, suffix)).replace('"', '').replace('.', '_')
if len(index_name) > self.max_index_name_length:
part = ('_%s%s%s' % (column_names[0], index_unique_name, suffix))
index_name = '%s%s' % (table_name[:(self.max_index_name_length - len(part))], part)
return index_name
def create_index_sql(self, table_name, column_names, unique=False, db_tablespace=''):
"""
Generates a create index statement on 'table_name' for a list of 'column_names'
"""
if not column_names:
print("No column names supplied on which to create an index")
return ''
connection = self._get_connection()
if db_tablespace and connection.features.supports_tablespaces:
tablespace_sql = ' ' + connection.ops.tablespace_sql(db_tablespace)
else:
tablespace_sql = ''
index_name = self.create_index_name(table_name, column_names)
return 'CREATE %sINDEX %s ON %s (%s)%s;' % (
unique and 'UNIQUE ' or '',
self.quote_name(index_name),
self.quote_name(table_name),
','.join([self.quote_name(field) for field in column_names]),
tablespace_sql
)
@invalidate_table_constraints
def create_index(self, table_name, column_names, unique=False, db_tablespace=''):
""" Executes a create index statement """
sql = self.create_index_sql(table_name, column_names, unique, db_tablespace)
self.execute(sql)
@invalidate_table_constraints
def delete_index(self, table_name, column_names, db_tablespace=''):
"""
Deletes an index created with create_index.
This is possible using only columns due to the deterministic
index naming function which relies on column names.
"""
if isinstance(column_names, string_types):
column_names = [column_names]
name = self.create_index_name(table_name, column_names)
sql = self.drop_index_string % {
"index_name": self.quote_name(name),
"table_name": self.quote_name(table_name),
}
self.execute(sql)
drop_index = alias('delete_index')
@delete_column_constraints
def delete_column(self, table_name, name):
"""
Deletes the column 'column_name' from the table 'table_name'.
"""
params = (self.quote_name(table_name), self.quote_name(name))
self.execute(self.delete_column_string % params, [])
drop_column = alias('delete_column')
def rename_column(self, table_name, old, new):
"""
Renames the column 'old' from the table 'table_name' to 'new'.
"""
raise NotImplementedError("rename_column has no generic SQL syntax")
@invalidate_table_constraints
def delete_primary_key(self, table_name):
"""
Drops the old primary key.
"""
# Dry runs mean we can't do anything.
if self.dry_run:
if self.debug:
print(' - no dry run output for delete_primary_key() due to dynamic DDL, sorry')
return
constraints = list(self._constraints_affecting_columns(table_name, None, type="PRIMARY KEY"))
if not constraints:
raise ValueError("Cannot find a PRIMARY KEY constraint on table %s" % (table_name,))
for constraint in constraints:
self.execute(self.delete_primary_key_sql % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(constraint),
})
drop_primary_key = alias('delete_primary_key')
@invalidate_table_constraints
def create_primary_key(self, table_name, columns):
"""
Creates a new primary key on the specified columns.
"""
if not isinstance(columns, (list, tuple)):
columns = [columns]
self.execute(self.create_primary_key_string % {
"table": self.quote_name(table_name),
"constraint": self.quote_name(table_name + "_pkey"),
"columns": ", ".join(map(self.quote_name, columns)),
})
def _find_primary_key_columns(self, table_name):
"""
Find all columns of the primary key of the specified table
"""
db_name = self._get_setting('NAME')
primary_key_columns = set()
for col, constraints in self.lookup_constraint(db_name, table_name):
for kind, cname in constraints:
if kind == 'PRIMARY KEY':
primary_key_columns.add(col.lower())
return primary_key_columns
def start_transaction(self):
"""
Makes sure the following commands are inside a transaction.
Must be followed by a (commit|rollback)_transaction call.
"""
if self.dry_run:
self.pending_transactions += 1
transaction.commit_unless_managed(using=self.db_alias)
transaction.enter_transaction_management(using=self.db_alias)
transaction.managed(True, using=self.db_alias)
def commit_transaction(self):
"""
Commits the current transaction.
Must be preceded by a start_transaction call.
"""
if self.dry_run:
return
transaction.commit(using=self.db_alias)
transaction.leave_transaction_management(using=self.db_alias)
def rollback_transaction(self):
"""
Rolls back the current transaction.
Must be preceded by a start_transaction call.
"""
if self.dry_run:
self.pending_transactions -= 1
transaction.rollback(using=self.db_alias)
transaction.leave_transaction_management(using=self.db_alias)
def rollback_transactions_dry_run(self):
"""
Rolls back all pending_transactions during this dry run.
"""
if not self.dry_run:
return
while self.pending_transactions > 0:
self.rollback_transaction()
if transaction.is_dirty(using=self.db_alias):
# Force an exception, if we're still in a dirty transaction.
# This means we are missing a COMMIT/ROLLBACK.
transaction.leave_transaction_management(using=self.db_alias)
def send_create_signal(self, app_label, model_names):
self.pending_create_signals.append((app_label, model_names))
def send_pending_create_signals(self, verbosity=0, interactive=False):
# Group app_labels together
signals = SortedDict()
for (app_label, model_names) in self.pending_create_signals:
try:
signals[app_label].extend(model_names)
except KeyError:
signals[app_label] = list(model_names)
# Send only one signal per app.
for (app_label, model_names) in signals.items():
self.really_send_create_signal(app_label, list(set(model_names)),
verbosity=verbosity,
interactive=interactive)
self.pending_create_signals = []
def really_send_create_signal(self, app_label, model_names,
verbosity=0, interactive=False):
"""
Sends a post_syncdb signal for the model specified.
If the model is not found (perhaps it's been deleted?),
no signal is sent.
TODO: The behavior of django.contrib.* apps seems flawed in that
they don't respect created_models. Rather, they blindly execute
over all models within the app sending the signal. This is a
patch we should push Django to make For now, this should work.
"""
if self.debug:
print(" - Sending post_syncdb signal for %s: %s" % (app_label, model_names))
app = models.get_app(app_label)
if not app:
return
created_models = []
for model_name in model_names:
model = models.get_model(app_label, model_name)
if model:
created_models.append(model)
if created_models:
if hasattr(dispatcher, "send"):
# Older djangos
dispatcher.send(signal=models.signals.post_syncdb, sender=app,
app=app, created_models=created_models,
verbosity=verbosity, interactive=interactive)
else:
if self._is_multidb():
# Django 1.2+
models.signals.post_syncdb.send(
sender=app,
app=app,
created_models=created_models,
verbosity=verbosity,
interactive=interactive,
db=self.db_alias,
)
else:
# Django 1.1 - 1.0
models.signals.post_syncdb.send(
sender=app,
app=app,
created_models=created_models,
verbosity=verbosity,
interactive=interactive,
)
def mock_model(self, model_name, db_table, db_tablespace='',
pk_field_name='id', pk_field_type=models.AutoField,
pk_field_args=[], pk_field_kwargs={}):
"""
Generates a MockModel class that provides enough information
to be used by a foreign key/many-to-many relationship.
Migrations should prefer to use these rather than actual models
as models could get deleted over time, but these can remain in
migration files forever.
Depreciated.
"""
class MockOptions(object):
def __init__(self):
self.db_table = db_table
self.db_tablespace = db_tablespace or settings.DEFAULT_TABLESPACE
self.object_name = model_name
self.module_name = model_name.lower()
if pk_field_type == models.AutoField:
pk_field_kwargs['primary_key'] = True
self.pk = pk_field_type(*pk_field_args, **pk_field_kwargs)
self.pk.set_attributes_from_name(pk_field_name)
self.abstract = False
def get_field_by_name(self, field_name):
# we only care about the pk field
return (self.pk, self.model, True, False)
def get_field(self, name):
# we only care about the pk field
return self.pk
class MockModel(object):
_meta = None
# We need to return an actual class object here, not an instance
MockModel._meta = MockOptions()
MockModel._meta.model = MockModel
return MockModel
def _db_positive_type_for_alter_column(self, klass, field):
"""
A helper for subclasses overriding _db_type_for_alter_column:
Remove the check constraint from the type string for PositiveInteger
and PositiveSmallInteger fields.
@param klass: The type of the child (required to allow this to be used when it is subclassed)
@param field: The field to generate type for
"""
super_result = super(klass, self)._db_type_for_alter_column(field)
if isinstance(field, (models.PositiveSmallIntegerField, models.PositiveIntegerField)):
return super_result.split(" ", 1)[0]
return super_result
def _alter_add_positive_check(self, klass, field, name, params, sqls):
"""
A helper for subclasses overriding _alter_add_column_mods:
Add a check constraint verifying positivity to PositiveInteger and
PositiveSmallInteger fields.
"""
super(klass, self)._alter_add_column_mods(field, name, params, sqls)
if isinstance(field, (models.PositiveSmallIntegerField, models.PositiveIntegerField)):
uniq_hash = abs(hash(tuple(params.values())))
d = dict(
constraint = "CK_%s_PSTV_%s" % (name, hex(uniq_hash)[2:]),
check = "%s >= 0" % self.quote_name(name))
sqls.append((self.add_check_constraint_fragment % d, []))
