MSSQL schema name is not passed to drop constraint statement #621
Description
Hello, I'm having problem with dropping default constraint using alter_column operation.
Here is my setup:
- Microsoft SQL Server 2017-CU12-ubuntu
- pyodbc 4.0.26
- alembic 1.3.0
- sqlalchemy 1.3.11
I have the following table in my database
def upgrade():
op.create_table('Client',
sa.Column('id', sa.Integer, primary_key=True),
sa.Column('name', sa.String(255), nullable=True),
schema='dm')
Suppose I have inserted few rows to table dm.Client
INSERT INTO dm.Client(name) values ('Sam'), ('John')
Now running the following upgrade fails
def upgrade():
op.add_column(table_name='Client', column=sa.Column('client_id', sa.Integer, nullable=False, server_default='1'), schema='dm')
op.alter_column(table_name='Client', column_name='client_id', schema='dm', server_default=None)
Error:
sqlalchemy.exc.ProgrammingError: (pyodbc.ProgrammingError) ('42000', "[42000] [Microsoft][ODBC SQL Server Driver][SQL Server]Incorrect syntax near 'constraint'. (102) (SQLExecDirectW)")
[SQL: declare @const_name varchar(256)
select @const_name = [name] from sys.default_constraints
where parent_object_id = object_id('Client')
and col_name(parent_object_id, parent_column_id) = 'client_id'
exec('alter table [Client] drop constraint ' + @const_name)]
(Background on this error at: http://sqlalche.me/e/f405)
The problem is that schema 'dm' is not passed to statement and therefore constraint is not found. The following statement is correct and drops the constraint.
declare @const_name varchar(256)
select @const_name = [name] from sys.default_constraints
where parent_object_id = object_id('dm.Client')
and col_name(parent_object_id, parent_column_id) = 'client_id'
exec('alter table [dm].[Client] drop constraint ' + @const_name)
I'm not sure if this is an issue with Alembic or SQL Alchemy.