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Informix Error -418

-418 NULL SQLDA descriptor or host variable list encountered.

Review the way the program constructs the sqlda and related data structures; somehow it is setting up a null pointer. If the program is in IBM Informix 4GL or another language in which the sqlda is not constructed directly by the program, or if this statement only refers to host variables by name, this error should not occur. If the error recurs, note all circumstances and contact IBM Informix Technical Support.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-418 is another member of the embedded-SQL/ESQL-C sqlda-construction error family alongside -402/-405: the program set up a null pointer where a valid SQLDA descriptor or host-variable list was expected. Per the official guidance, this shouldn't normally occur in higher-level environments like IBM Informix 4GL, where sqlda isn't constructed directly by the program, or in statements that only reference host variables by name rather than a descriptor.

  1. Manual sqlda construction leaving the descriptor pointer itself null, rather than just one field within it.
  2. A statement expecting either a descriptor or a host-variable list, and receiving neither — both were omitted or improperly initialized.
  3. A bug in lower-level embedded SQL/ESQL-C client code managing these structures directly, as opposed to a higher-level language handling it automatically.
Solutions / Resolution
  1. Review how the program constructs the sqlda and related data structures, per the official guidance, for a null pointer where a valid one is expected.
  2. If using a higher-level language (4GL and similar) where this shouldn't normally occur, treat its appearance as a signal of a runtime or generated-code bug, not an application input mistake.
  3. If the problem persists after reviewing the construction code, document all relevant circumstances and contact IBM Informix Technical Support, per the official guidance.
Examples
Reviewing manual SQLDA construction for a null descriptor
/* Confirm the sqlda pointer itself (not just fields within it)
   is properly allocated and non-null before use in a dynamic
   SQL statement. */
struct sqlda *desc = NULL;  /* bug: never actually allocated */
EXECUTE stmt1 USING DESCRIPTOR desc;
Diagnostic Checks
  1. Check whether the sqlda/descriptor pointer itself is null, not just a field within a valid structure.
  2. Confirm whether the client code is a higher-level language (4GL and similar) where this shouldn't normally occur at all.
Related Errors / Related Topics
  • -402 — "Address of a host variable is NULL." A closely related sibling — a null pointer at the individual host-variable level rather than the descriptor/list level.
  • -411 — "Cannot specify both host variables and descriptor." Another related error in the same general host-variable/descriptor-handling family, about a conflicting combination rather than a missing one.

Review sqlda/descriptor construction for a null pointer at the top level — this shouldn't occur at all in higher-level languages like 4GL, so its appearance there points to a genuine bug.