DECLARE @tableName VARCHAR(MAX) = 'm_PWT' DECLARE @columnName VARCHAR(MAX) = 'countInDoc' DECLARE @ConstraintName nvarchar(200) SELECT @ConstraintName = Name FROM SYS.DEFAULT_CONSTRAINTS WHERE PARENT_OBJECT_ID = OBJECT_ID(@tableName) AND PARENT_COLUMN_ID = ( SELECT column_id FROM sys.columns WHERE NAME = @columnName AND object_id = OBJECT_ID(@tableName)) IF @ConstraintName IS NOT NULL EXEC('ALTER TABLE '+@tableName+' DROP CONSTRAINT ' + @ConstraintName)