In this blog post, let’s learn about the error message “1275 Constraint constraint1 cannot be dropped because it is needed by unique constraint constraint2.” when working with HPE NonStop SQL/MX, the reason for the error and the solution to fix this error message.
Error Message
1275 Constraint constraint1 cannot be dropped because it is needed by unique constraint constraint2.
Reason for the Error
You attempted to drop a constraint that is needed by a UNIQUE constraint, which is not allowed because it would leave a UNIQUE constraint on a column, but without a NOT NULL constraint for that column.
Solution
To drop the constraint, you must remove the UNIQUE constraint or add an additional NOT NULL constraint to the columns that contain UNIQUE constraints and only one NOT NULL constraint for that column
