016_uuids_everywhere.py 文件源码

def create_uuids(migrate_engine, primary_table_name, revision_table_name):
    # have changed type of cols so recreate metadata
    metadata = MetaData(migrate_engine)

    # 4 create uuids for primary entities and in related tables
    primary_table = Table(primary_table_name, metadata, autoload=True)
    if revision_table_name:
        revision_table = Table(revision_table_name, metadata, autoload=True)
    # fetchall wouldn't be optimal with really large sets of data but here <20k
    ids = [ res[0] for res in
            migrate_engine.execute(select([primary_table.c.id])).fetchall() ]
    for count,id in enumerate(ids):
        # if count % 100 == 0: print(count, id)
        myuuid = make_uuid()
        update = primary_table.update().where(primary_table.c.id==id).values(id=myuuid)
        migrate_engine.execute(update)
    if revision_table_name:
        # ensure each id in revision table match its continuity id.
        q = revision_table.update().values(id=revision_table.c.continuity_id)
        migrate_engine.execute(q)