Informix Error -765: Cannot EXECUTE a statement that has been DECLAREd.

Reasons / Common Causes

-765 fires when EXECUTE is issued against a prepared statement that was instead DECLAREd as a cursor — per the official guidance, a declared statement follows the cursor lifecycle (DECLARE/OPEN/FETCH/CLOSE), not the EXECUTE lifecycle; the two are mutually exclusive ways of running a prepared statement.

1. A prepared statement DECLAREd as a cursor, then EXECUTEd instead of OPENed/FETCHed, per the official guidance — the direct, only cause.
2. Code written for a singleton SELECT (one row, no cursor needed) that used the DECLARE/OPEN/FETCH cursor pattern instead of the simpler EXECUTE INTO form, then mixed the two patterns by also trying EXECUTE.

Solutions / Resolution

1. Use OPEN/FETCH/CLOSE for a statement that was DECLAREd, per the official guidance — follow the cursor lifecycle consistently.
2. For a singleton SELECT with output variables, use EXECUTE ... INTO (or EXECUTE PROCEDURE ... INTO) instead of declaring a cursor at all, per the official guidance — this is the simpler, more direct mechanism for the one-row case, avoiding the cursor lifecycle entirely.

Examples

The disallowed mix

EXEC SQL PREPARE stmt_id FROM 'SELECT status FROM orders WHERE order_id = ?';
EXEC SQL DECLARE cur1 CURSOR FOR stmt_id;
EXEC SQL EXECUTE stmt_id INTO :status USING :order_id;
/* -765: stmt_id was DECLAREd as a cursor, not meant for EXECUTE */

Corrected — follow the cursor lifecycle

EXEC SQL PREPARE stmt_id FROM 'SELECT status FROM orders WHERE order_id = ?';
EXEC SQL DECLARE cur1 CURSOR FOR stmt_id;
EXEC SQL OPEN cur1 USING :order_id;
EXEC SQL FETCH cur1 INTO :status;
EXEC SQL CLOSE cur1;

Or corrected — EXECUTE INTO for a singleton SELECT, no cursor needed

EXEC SQL PREPARE stmt_id FROM 'SELECT status FROM orders WHERE order_id = ?';
EXEC SQL EXECUTE stmt_id INTO :status USING :order_id;

Diagnostic Checks

1. Check whether the prepared statement was DECLAREd as a cursor, and if so, use OPEN/FETCH/CLOSE rather than EXECUTE — or switch to EXECUTE ... INTO and drop the DECLARE entirely if it's a singleton SELECT.

Related Errors / Related Topics

No closely related error codes are cross-referenced for -765 in this set yet.

DECLARE and EXECUTE are two separate, mutually exclusive ways to run a prepared statement — use EXECUTE ... INTO for a singleton SELECT instead of mixing the two.