42P03ERRORTier 2 — Caution✅ HIGH confidence

duplicate cursor

Category: Syntax Error or Access Rule ViolationVersions: All Postgres versions

What this means

SQLSTATE 42P03 is a Postgres-specific error raised when a DECLARE CURSOR statement attempts to create a cursor with a name that is already in use in the current transaction.

Why it happens

1DECLARE CURSOR uses a name that was already declared and not yet closed in the current session or transaction

How to reproduce

Declaring a cursor with a duplicate name.

trigger — this will ERROR

DECLARE my_cursor CURSOR FOR SELECT * FROM orders;
DECLARE my_cursor CURSOR FOR SELECT * FROM customers; -- duplicate name

ERROR: cursor "my_cursor" already exists

Fix 1: Close the existing cursor before declaring a new one with the same name

When cursor names may clash.

fix

CLOSE my_cursor;
DECLARE my_cursor CURSOR FOR SELECT * FROM customers;

Why this works

CLOSE releases the cursor name, allowing it to be reused.

Fix 2: Use unique cursor names

When managing multiple cursors in a stored procedure.

fix

Why this works

Generate unique cursor names (e.g., including a counter or timestamp suffix) to avoid name collisions.

Sources

📚 Official docs: https://www.postgresql.org/docs/current/errcodes-appendix.html

🔧 Source ref: Class 42 — Syntax Error or Access Rule Violation (Postgres-specific)

Confidence assessment

✅ HIGH confidence

Postgres-specific. Stable across all versions.