129 lines
4.9 KiB
Python
129 lines
4.9 KiB
Python
# engine/ddl.py
|
|
# Copyright (C) 2009, 2010 Michael Bayer mike_mp@zzzcomputing.com
|
|
#
|
|
# This module is part of SQLAlchemy and is released under
|
|
# the MIT License: http://www.opensource.org/licenses/mit-license.php
|
|
|
|
"""Routines to handle CREATE/DROP workflow."""
|
|
|
|
from sqlalchemy import engine, schema
|
|
from sqlalchemy.sql import util as sql_util
|
|
|
|
|
|
class DDLBase(schema.SchemaVisitor):
|
|
def __init__(self, connection):
|
|
self.connection = connection
|
|
|
|
class SchemaGenerator(DDLBase):
|
|
def __init__(self, dialect, connection, checkfirst=False, tables=None, **kwargs):
|
|
super(SchemaGenerator, self).__init__(connection, **kwargs)
|
|
self.checkfirst = checkfirst
|
|
self.tables = tables and set(tables) or None
|
|
self.preparer = dialect.identifier_preparer
|
|
self.dialect = dialect
|
|
|
|
def _can_create(self, table):
|
|
self.dialect.validate_identifier(table.name)
|
|
if table.schema:
|
|
self.dialect.validate_identifier(table.schema)
|
|
return not self.checkfirst or not self.dialect.has_table(self.connection, table.name, schema=table.schema)
|
|
|
|
def visit_metadata(self, metadata):
|
|
if self.tables:
|
|
tables = self.tables
|
|
else:
|
|
tables = metadata.tables.values()
|
|
collection = [t for t in sql_util.sort_tables(tables) if self._can_create(t)]
|
|
|
|
for listener in metadata.ddl_listeners['before-create']:
|
|
listener('before-create', metadata, self.connection, tables=collection)
|
|
|
|
for table in collection:
|
|
self.traverse_single(table)
|
|
|
|
for listener in metadata.ddl_listeners['after-create']:
|
|
listener('after-create', metadata, self.connection, tables=collection)
|
|
|
|
def visit_table(self, table):
|
|
for listener in table.ddl_listeners['before-create']:
|
|
listener('before-create', table, self.connection)
|
|
|
|
for column in table.columns:
|
|
if column.default is not None:
|
|
self.traverse_single(column.default)
|
|
|
|
self.connection.execute(schema.CreateTable(table))
|
|
|
|
if hasattr(table, 'indexes'):
|
|
for index in table.indexes:
|
|
self.traverse_single(index)
|
|
|
|
for listener in table.ddl_listeners['after-create']:
|
|
listener('after-create', table, self.connection)
|
|
|
|
def visit_sequence(self, sequence):
|
|
if self.dialect.supports_sequences:
|
|
if ((not self.dialect.sequences_optional or
|
|
not sequence.optional) and
|
|
(not self.checkfirst or
|
|
not self.dialect.has_sequence(self.connection, sequence.name, schema=sequence.schema))):
|
|
self.connection.execute(schema.CreateSequence(sequence))
|
|
|
|
def visit_index(self, index):
|
|
self.connection.execute(schema.CreateIndex(index))
|
|
|
|
|
|
class SchemaDropper(DDLBase):
|
|
def __init__(self, dialect, connection, checkfirst=False, tables=None, **kwargs):
|
|
super(SchemaDropper, self).__init__(connection, **kwargs)
|
|
self.checkfirst = checkfirst
|
|
self.tables = tables
|
|
self.preparer = dialect.identifier_preparer
|
|
self.dialect = dialect
|
|
|
|
def visit_metadata(self, metadata):
|
|
if self.tables:
|
|
tables = self.tables
|
|
else:
|
|
tables = metadata.tables.values()
|
|
collection = [t for t in reversed(sql_util.sort_tables(tables)) if self._can_drop(t)]
|
|
|
|
for listener in metadata.ddl_listeners['before-drop']:
|
|
listener('before-drop', metadata, self.connection, tables=collection)
|
|
|
|
for table in collection:
|
|
self.traverse_single(table)
|
|
|
|
for listener in metadata.ddl_listeners['after-drop']:
|
|
listener('after-drop', metadata, self.connection, tables=collection)
|
|
|
|
def _can_drop(self, table):
|
|
self.dialect.validate_identifier(table.name)
|
|
if table.schema:
|
|
self.dialect.validate_identifier(table.schema)
|
|
return not self.checkfirst or self.dialect.has_table(self.connection, table.name, schema=table.schema)
|
|
|
|
def visit_index(self, index):
|
|
self.connection.execute(schema.DropIndex(index))
|
|
|
|
def visit_table(self, table):
|
|
for listener in table.ddl_listeners['before-drop']:
|
|
listener('before-drop', table, self.connection)
|
|
|
|
for column in table.columns:
|
|
if column.default is not None:
|
|
self.traverse_single(column.default)
|
|
|
|
self.connection.execute(schema.DropTable(table))
|
|
|
|
for listener in table.ddl_listeners['after-drop']:
|
|
listener('after-drop', table, self.connection)
|
|
|
|
def visit_sequence(self, sequence):
|
|
if self.dialect.supports_sequences:
|
|
if ((not self.dialect.sequences_optional or
|
|
not sequence.optional) and
|
|
(not self.checkfirst or
|
|
self.dialect.has_sequence(self.connection, sequence.name, schema=sequence.schema))):
|
|
self.connection.execute(schema.DropSequence(sequence))
|