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Informix Error -412

-412 Command pointer is NULL.

This statement (probably an EXECUTE or DECLARE) refers to a dynamic SQL statement that has never been prepared or that has been freed. Review the program logic to ensure that the statement has been prepared, the PREPARE did not return an error code, and the FREE statement has not been used to release the statement before this point.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-412 is a close sibling of -410/-404: an EXECUTE or DECLARE references a dynamic SQL statement whose internal command pointer is null — either because it was never successfully prepared, or because it was prepared and then already freed with FREE.

  1. EXECUTE/DECLARE referencing a statement identifier that was never PREPAREd.
  2. PREPARE was attempted but failed, leaving the statement identifier without a valid command pointer, and the failure wasn't checked before proceeding.
  3. The statement was already FREEd, and EXECUTE/DECLARE was attempted against it afterward without re-preparing.
Solutions / Resolution
  1. Review program logic to verify the statement was successfully prepared (check PREPARE's return code), per the official guidance.
  2. Confirm FREE hasn't been called prematurely on the statement before the failing EXECUTE/DECLARE.
  3. Re-prepare the statement if it needs to be used again after being freed — a freed statement identifier isn't reusable without another PREPARE.
Examples
Using a statement after it was freed
PREPARE stmt1 FROM 'SELECT * FROM orders WHERE order_id = ?';
DECLARE curs1 CURSOR FOR stmt1;
FREE stmt1;
OPEN curs1;
-- -412: stmt1's command pointer is null after FREE

Fix — don't free the statement until done with any cursors declared against it, or re-prepare before reuse:

PREPARE stmt1 FROM 'SELECT * FROM orders WHERE order_id = ?';
DECLARE curs1 CURSOR FOR stmt1;
OPEN curs1;
-- ... use the cursor ...
CLOSE curs1;
FREE stmt1;
Diagnostic Checks
  1. Check whether PREPARE succeeded for the statement identifier in question.
  2. Check whether FREE was called on the statement before the failing EXECUTE/DECLARE.
Related Errors / Related Topics
  • -410 — "Prepare statement failed or was not executed." The closest sibling — the same general class of unprepared/failed-preparation error.
  • -404 — "The cursor or statement is not available." A related, broader cursor/statement- lifecycle error covering several similar scenarios, including a freed statement.

Check whether the statement was successfully prepared and hasn't since been freed — this is the same underlying discipline as -410, applied to DECLARE as well as EXECUTE.