Informix Error -944: Cannot use "first", "limit" or "skip" in this context.

Reasons / Common Causes

-944 fires when FIRST N, LIMIT N, or SKIP M is used inside a subquery — per the official guidance, these clauses are only supported on the outer main query's SELECT, not within a nested subquery.

1. FIRST N/LIMIT N/SKIP M used inside a subquery, per the official guidance — the direct, only cause.
2. A query pattern that works for the outer SELECT, mistakenly applied to a subquery expecting the same row-limiting behavior there.

Solutions / Resolution

1. Review the use of FIRST N/LIMIT N/SKIP M and confirm it's applied only to the outer main query's SELECT clause, per the official guidance.
2. If row-limiting is genuinely needed within what would be a subquery, restructure the query — for example, materialize the limited subquery's result into a temp table first via its own top-level SELECT ... INTO TEMP, then join against that temp table in the outer query.

Examples

The disallowed attempt

SELECT * FROM orders WHERE order_id IN
  (SELECT FIRST 10 order_id FROM order_items ORDER BY item_count DESC);
-- -944: FIRST used inside a subquery

Corrected — materialize the limited result first

SELECT FIRST 10 order_id FROM order_items ORDER BY item_count DESC
  INTO TEMP top_orders;

SELECT * FROM orders WHERE order_id IN (SELECT order_id FROM top_orders);

Diagnostic Checks

1. Scan the statement for FIRST/LIMIT/SKIP appearing inside a subquery rather than the outer SELECT.

Related Errors / Related Topics

No closely related error codes are cross-referenced for -944 in this set yet.

FIRST/LIMIT/SKIP only work on the outer query — materialize a limited subquery's result into a temp table first if row-limiting is needed there.