def digest(connection, *args):
"""Return a digest hash for a set of arguments.
This is mostly used as part of the index/constraint name generation
processes. It offers compatibility with a range of Django versions.
Args:
connection (object):
The database connection.
*args (tuple):
The positional arguments used to build the digest hash out of.
Returns:
str:
The resulting digest hash.
"""
if (BaseDatabaseSchemaEditor and
hasattr(BaseDatabaseSchemaEditor, '_digest')):
# Django >= 1.8
#
# Note that _digest() is a classmethod that is common across all
# database backends. We don't need to worry about using a
# per-instance version. If that changes, we'll need to create a
# SchemaEditor.
return BaseDatabaseSchemaEditor._digest(*args)
else:
# Django < 1.8
return connection.creation._digest(*args)
def _sql_indexes_for_field(self, model, field):
"""
Return the CREATE INDEX SQL statements for a single model field
:param model:
:param field:
:return:
"""
def qn(name):
if name.startswith('"') and name.endswith('"'):
return name # Quoting once is enough.
return '"%s"' % name
max_name_length = 63
if field.db_index and not field.unique:
i_name = "%s_%s" % (
model._meta.db_table,
BaseDatabaseSchemaEditor._digest(field.column),
)
return [
"CREATE INDEX %s ON %s(%s)" % (
qn(truncate_name(i_name, max_name_length)),
qn(model._meta.db_table),
qn(field.column),
)
]
return []
def digest(connection, *args):
"""Return a digest hash for a set of arguments.
This is mostly used as part of the index/constraint name generation
processes. It offers compatibility with a range of Django versions.
Args:
connection (object):
The database connection.
*args (tuple):
The positional arguments used to build the digest hash out of.
Returns:
str:
The resulting digest hash.
"""
if (BaseDatabaseSchemaEditor
and hasattr(BaseDatabaseSchemaEditor, '_digest')):
# Django >= 1.8
#
# Note that _digest() is a classmethod that is common across all
# database backends. We don't need to worry about using a
# per-instance version. If that changes, we'll need to create a
# SchemaEditor.
return BaseDatabaseSchemaEditor._digest(*args)
else:
# Django < 1.8
return connection.creation._digest(*args)