SQLCODE -530 foreign key violation

SQLCODE -530: foreign key violation — the parent row for your foreign key does not exist.

What it means

• After every EXEC SQL, DB2 returns a SQLCODE: 0 means success, +100 means no row found, and negative values mean an error.

Common causes

• Inserting a child row with a parent key that is not in the parent table.
• Wrong key value from input data.

How to diagnose

• Verify the parent key exists: SELECT it in SPUFI.
• Check the input key values.

How to fix it

• Insert the parent row first, or correct the key.
• Validate keys against the parent table before insert.

Example: Validate against the parent first

Parent-first ordering prevents -530.

Interview tip

• Q: How would you troubleshoot a SQLCODE -530 foreign key violation in production?
• A: I would check the SQLCODE and SQLERRM immediately after the failing statement, reproduce in SPUFI, then apply the specific fix.

Prevention checklist

• Always check SQLCODE after every EXEC SQL statement.
• Log the SQLCODE, SQLSTATE and failing statement for support.