django1/django/db/backends/mysql/schema.py

54 lines
2.2 KiB
Python

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"
sql_delete_pk = "ALTER TABLE %(table)s DROP PRIMARY KEY"
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
import MySQLdb.converters
return MySQLdb.escape(value, MySQLdb.converters.conversions)
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])