openstack
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neutron
Code Issues Proposed changes

Postgresql: add do_drop arg in alter_enum function 

When postgresql is used as the backend and alter_enum is called.
The old type of enum will be dropped. But there is a case which
the old type is used by more than one column, in different table
eg. Then the drop operation will be failed. Add do_drop,do_rename,
do_create to let developer to decide whether these operations should
be skipped or not.

Change-Id: I708288e2cc507017d9f6512b567e3bfc77dfd761
Closes-Bug: #1568436
This commit is contained in:
nick.zhuyj 2016-04-09 21:42:52 -05:00
parent 8582373d61
commit 8d6f3bde1b
1 changed files with 21 additions and 4 deletions
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25
neutron/db/migration/__init__.py
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@ -114,22 +114,39 @@ def rename_table_if_exists(old_table_name, new_table_name):
op.rename_table(old_table_name, new_table_name)
def alter_enum(table, column, enum_type, nullable):
def alter_enum(table, column, enum_type, nullable, do_drop=True,
do_rename=True, do_create=True):
"""Alter a enum type column.
Set the do_xx parameters only when the modified enum type
is used by multiple columns. Else don't provide these
parameters.
:param do_drop: set to False when modified column is
not the last one use this enum
:param do_rename: set to False when modified column is
not the first one use this enum
:param do_create: set to False when modified column is
not the first one use this enum
"""
bind = op.get_bind()
engine = bind.engine
if engine.name == 'postgresql':
values = {'table': table,
'column': column,
'name': enum_type.name}
op.execute("ALTER TYPE %(name)s RENAME TO old_%(name)s" % values)
enum_type.create(bind, checkfirst=False)
if do_rename:
op.execute("ALTER TYPE %(name)s RENAME TO old_%(name)s" % values)
if do_create:
enum_type.create(bind, checkfirst=False)
op.execute("ALTER TABLE %(table)s RENAME COLUMN %(column)s TO "
"old_%(column)s" % values)
op.add_column(table, sa.Column(column, enum_type, nullable=nullable))
op.execute("UPDATE %(table)s SET %(column)s = "
"old_%(column)s::text::%(name)s" % values)
op.execute("ALTER TABLE %(table)s DROP COLUMN old_%(column)s" % values)
op.execute("DROP TYPE old_%(name)s" % values)
if do_drop:
op.execute("DROP TYPE old_%(name)s" % values)
else:
op.alter_column(table, column, type_=enum_type,
existing_nullable=nullable)