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.
self._drop_constraints(table_name, name, field)
# First, change the type
params = {
"column": self.quote_name(name),
"type": self._db_type_for_alter_column(field),
"table_name": table_name
}
# SQLs is a list of (SQL, values) pairs.
sqls = []
sqls_extra = []
# 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: modified, firebird doesn't support DROP NOT NULL
sqls_extra.append(self._alter_column_set_null(table_name, name, field.null))
# Next, set any default
self._alter_set_defaults(field, name, params, sqls)
# Finally, actually change the column
if self.allows_combined_alters:
sqls, values = list(zip(*sqls))
self.execute(
"ALTER TABLE %s %s;" % (self.quote_name(table_name), ", ".join(sqls)),
generic.flatten(values),
)
else:
# Databases like e.g. MySQL don't like more than one alter at once.
for sql, values in sqls:
try:
self.execute("ALTER TABLE %s %s;" % (self.quote_name(table_name), sql), values)
except DatabaseError as e:
print(e)
# Execute extra sql, which don't need ALTER TABLE statement
for sql in sqls_extra:
self.execute(sql)
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 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 or add UNIQUE constraint
unique_constraint = list(
self._constraints_affecting_columns(table_name, [name], "UNIQUE"))
if field.unique and not unique_constraint:
self.create_unique(table_name, [name])
elif not field.unique and unique_constraint:
self.delete_unique(table_name, [name])
# 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": 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:
sqls.append((self.alter_string_set_null % params, []))
else:
sqls.append((self.alter_string_drop_null % params, []))
# Next, set any default
self._alter_set_defaults(field, name, params, sqls)
# Finally, actually change the column
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 ignore_constraints:
# Add back FK constraints if needed
if field.rel and self.supports_foreign_keys:
# HACK: "soft" FK handling begin
if not hasattr(field,
'no_db_constraints') or not field.no_db_constraints:
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 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.
self._drop_constraints(table_name, name, field)
# First, change the type
params = {
"column": self.quote_name(name),
"type": self._db_type_for_alter_column(field),
"table_name": table_name
}
# SQLs is a list of (SQL, values) pairs.
sqls = []
sqls_extra = []
# 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: modified, firebird doesn't support DROP NOT NULL
sqls_extra.append(
self._alter_column_set_null(table_name, name, field.null))
# Next, set any default
self._alter_set_defaults(field, name, params, sqls)
# Finally, actually change the column
if self.allows_combined_alters:
sqls, values = list(zip(*sqls))
self.execute(
"ALTER TABLE %s %s;" %
(self.quote_name(table_name), ", ".join(sqls)),
generic.flatten(values),
)
else:
# Databases like e.g. MySQL don't like more than one alter at once.
for sql, values in sqls:
try:
self.execute(
"ALTER TABLE %s %s;" %
(self.quote_name(table_name), sql), values)
except DatabaseError as e:
print(e)
# Execute extra sql, which don't need ALTER TABLE statement
for sql in sqls_extra:
self.execute(sql)
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 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 or add UNIQUE constraint
unique_constraint = list(self._constraints_affecting_columns(table_name, [name], "UNIQUE"))
if field.unique and not unique_constraint:
self.create_unique(table_name, [name])
elif not field.unique and unique_constraint:
self.delete_unique(table_name, [name])
# 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": 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:
sqls.append((self.alter_string_set_null % params, []))
else:
sqls.append((self.alter_string_drop_null % params, []))
# Next, set any default
self._alter_set_defaults(field, name, params, sqls)
# Finally, actually change the column
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 ignore_constraints:
# Add back FK constraints if needed
if field.rel and self.supports_foreign_keys:
# HACK: "soft" FK handling begin
if not hasattr(field, 'no_db_constraints') or not field.no_db_constraints:
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
)
)
