# MySQL Connector/Python - MySQL driver written in Python.
# New file added for Django 1.7
import django
if django.VERSION >= (1, 8):
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
else:
from django.db.backends.schema import BaseDatabaseSchemaEditor
from django.db.models import NOT_PROVIDED
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
sql_rename_table = "RENAME TABLE %(old_table)s TO %(new_table)s"
sql_alter_column_null = "MODIFY %(column)s %(type)s NULL"
sql_alter_column_not_null = "MODIFY %(column)s %(type)s NOT NULL"
sql_alter_column_type = "MODIFY %(column)s %(type)s"
sql_rename_column = "ALTER TABLE %(table)s CHANGE %(old_column)s " \
"%(new_column)s %(type)s"
sql_delete_unique = "ALTER TABLE %(table)s DROP INDEX %(name)s"
sql_create_fk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s FOREIGN " \
"KEY (%(column)s) REFERENCES %(to_table)s (%(to_column)s)"
sql_delete_fk = "ALTER TABLE %(table)s DROP FOREIGN KEY %(name)s"
sql_delete_index = "DROP INDEX %(name)s ON %(table)s"
alter_string_set_null = 'MODIFY %(column)s %(type)s NULL;'
alter_string_drop_null = 'MODIFY %(column)s %(type)s NOT NULL;'
sql_create_pk = "ALTER TABLE %(table)s ADD CONSTRAINT %(name)s " \
"PRIMARY KEY (%(columns)s)"
sql_delete_pk = "ALTER TABLE %(table)s DROP PRIMARY KEY"
def quote_value(self, value):
# Inner import to allow module to fail to load gracefully
from mysql.connector.conversion import MySQLConverter
return MySQLConverter.quote(MySQLConverter.escape(value))
def skip_default(self, field):
"""
MySQL doesn't accept default values for longtext and longblob
and implicitly treats these columns as nullable.
"""
return field.db_type(self.connection) in ('longtext', 'longblob')
def add_field(self, model, field):
super(DatabaseSchemaEditor, self).add_field(model, field)
# Simulate the effect of a one-off default.
if (self.skip_default(field)
and field.default not in (None, NOT_PROVIDED)):
effective_default = self.effective_default(field)
self.execute('UPDATE %(table)s SET %(column)s = %%s' % {
'table': self.quote_name(model._meta.db_table),
'column': self.quote_name(field.column),
}, [effective_default])
def _model_indexes_sql(self, model):
# New in Django 1.8
storage = self.connection.introspection.get_storage_engine(
self.connection.cursor(), model._meta.db_table
)
if storage == "InnoDB":
for field in model._meta.local_fields:
if (field.db_index and not field.unique
and field.get_internal_type() == "ForeignKey"):
# Temporary setting db_index to False (in memory) to
# disable index creation for FKs (index automatically
# created by MySQL)
field.db_index = False
return super(DatabaseSchemaEditor, self)._model_indexes_sql(model)
def _alter_column_type_sql(self, table, old_field, new_field, new_type):
# New in Django 1.8
# Keep null property of old field, if it has changed, it will be
# handled separately
if old_field.null:
new_type += " NULL"
else:
new_type += " NOT NULL"
return super(DatabaseSchemaEditor, self)._alter_column_type_sql(
table, old_field, new_field, new_type)
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