64 lines
2.2 KiB
Python
64 lines
2.2 KiB
Python
from django.db.backends.schema import BaseDatabaseSchemaEditor
|
|
|
|
|
|
class DatabaseSchemaEditor(BaseDatabaseSchemaEditor):
|
|
|
|
sql_create_sequence = "CREATE SEQUENCE %(sequence)s"
|
|
sql_delete_sequence = "DROP SEQUENCE IF EXISTS %(sequence)s CASCADE"
|
|
sql_set_sequence_max = "SELECT setval('%(sequence)s', MAX(%(column)s)) FROM %(table)s"
|
|
|
|
def quote_value(self, value):
|
|
# Inner import so backend fails nicely if it's not present
|
|
import psycopg2
|
|
return psycopg2.extensions.adapt(value)
|
|
|
|
def _alter_column_type_sql(self, table, column, type):
|
|
"""
|
|
Makes ALTER TYPE with SERIAL make sense.
|
|
"""
|
|
if type.lower() == "serial":
|
|
sequence_name = "%s_%s_seq" % (table, column)
|
|
return (
|
|
(
|
|
self.sql_alter_column_type % {
|
|
"column": self.quote_name(column),
|
|
"type": "integer",
|
|
},
|
|
[],
|
|
),
|
|
[
|
|
(
|
|
self.sql_delete_sequence % {
|
|
"sequence": sequence_name,
|
|
},
|
|
[],
|
|
),
|
|
(
|
|
self.sql_create_sequence % {
|
|
"sequence": sequence_name,
|
|
},
|
|
[],
|
|
),
|
|
(
|
|
self.sql_alter_column % {
|
|
"table": table,
|
|
"changes": self.sql_alter_column_default % {
|
|
"column": column,
|
|
"default": "nextval('%s')" % sequence_name,
|
|
}
|
|
},
|
|
[],
|
|
),
|
|
(
|
|
self.sql_set_sequence_max % {
|
|
"table": table,
|
|
"column": column,
|
|
"sequence": sequence_name,
|
|
},
|
|
[],
|
|
),
|
|
],
|
|
)
|
|
else:
|
|
return super(DatabaseSchemaEditor, self)._alter_column_type_sql(table, column, type)
|