Matt Riedemann 85317aead6 Add DB2 10.5 Support
This patch adds the initial support for DB2 10.5 to migrate. It
includes:

1. The dialect implementation for DB2.
2. The dialect registration with the visitor.
3. Code to parse the engine name in version.py.
4. A new dependency on ibm_db_sa in test-requirements.txt.
5. A connection string in test_db.cfg for ibm_db_sa.

Part of blueprint add-db2-support

Co-authored-by: Sheng Bo Hou <sbhou@cn.ibm.com>
Co-authored-by: Thuy Christenson <thuy@us.ibm.com>
Co-authored-by: Rahul Priyadarshi <rahul.priyadarshi@in.ibm.com>
Change-Id: I745ec615487b1b06c5d1a09ea316f376d66ee4c0
2014-02-17 07:17:31 -08:00

81 lines
2.4 KiB
Python

"""
Module for visitor class mapping.
"""
import sqlalchemy as sa
from migrate.changeset import ansisql
from migrate.changeset.databases import (sqlite,
postgres,
mysql,
oracle,
firebird,
ibmdb2)
# Map SA dialects to the corresponding Migrate extensions
DIALECTS = {
"default": ansisql.ANSIDialect,
"sqlite": sqlite.SQLiteDialect,
"postgres": postgres.PGDialect,
"postgresql": postgres.PGDialect,
"mysql": mysql.MySQLDialect,
"oracle": oracle.OracleDialect,
"firebird": firebird.FBDialect,
"ibm_db_sa": ibmdb2.IBMDBDialect
}
def get_engine_visitor(engine, name):
"""
Get the visitor implementation for the given database engine.
:param engine: SQLAlchemy Engine
:param name: Name of the visitor
:type name: string
:type engine: Engine
:returns: visitor
"""
# TODO: link to supported visitors
return get_dialect_visitor(engine.dialect, name)
def get_dialect_visitor(sa_dialect, name):
"""
Get the visitor implementation for the given dialect.
Finds the visitor implementation based on the dialect class and
returns and instance initialized with the given name.
Binds dialect specific preparer to visitor.
"""
# map sa dialect to migrate dialect and return visitor
sa_dialect_name = getattr(sa_dialect, 'name', 'default')
migrate_dialect_cls = DIALECTS[sa_dialect_name]
visitor = getattr(migrate_dialect_cls, name)
# bind preparer
visitor.preparer = sa_dialect.preparer(sa_dialect)
return visitor
def run_single_visitor(engine, visitorcallable, element,
connection=None, **kwargs):
"""Taken from :meth:`sqlalchemy.engine.base.Engine._run_single_visitor`
with support for migrate visitors.
"""
if connection is None:
conn = engine.contextual_connect(close_with_result=False)
else:
conn = connection
visitor = visitorcallable(engine.dialect, conn)
try:
if hasattr(element, '__migrate_visit_name__'):
fn = getattr(visitor, 'visit_' + element.__migrate_visit_name__)
else:
fn = getattr(visitor, 'visit_' + element.__visit_name__)
fn(element, **kwargs)
finally:
if connection is None:
conn.close()