SQL remove autonamed constraints

Question

I have created a few constraints on my table with a script without specifying the constraint name. As a result, I ended up having constraints like FK__DOC_OBGS___kntr___54E63309 for example.

Is it possible to drop that constraints without specifying the exact constraint name ?

For example, something like this (which doesn't work)

ALTER TABLE DOC_OBGS_10 DROP CONSTRAINT LIKE 'FK__DOC_OBGS___kntr%'

The problem is that we have a lot of databases with this table and I need to remove all the constraints from the tables, but apparently the name is different for each table.

Answer 1

DDL commands in SQL do not cooperate with like operator.

However, you may use information_schema views and easily build SQL for drop constraint commands, like this:

SELECT 'ALTER TABLE DOC_OBGS_10 DROP CONSTRAINT ' + CONSTRAINT_NAME
FROM INFORMATION_SCHEMA.REFERENTIAL_CONSTRAINTS 
WHERE CONSTRAINT_NAME LIKE 'FK__DOC_OBGS___kntr%'

Answer 2

DECLARE @sql1 NVARCHAR(MAX);
SELECT @sql1 = c
FROM
(
    SELECT 'ALTER TABLE DOC_INVS_1 DROP CONSTRAINT ' + CONSTRAINT_NAME + '; '
    FROM INFORMATION_SCHEMA.TABLE_CONSTRAINTS WHERE TABLE_NAME = 'DOC_INVS_1'
    and CONSTRAINT_NAME LIKE 'FK__DOC_INVS___kntr%' 
) T(c);

EXEC(@sql1);