Informix Error -642

-642 Family name must be a character string.

The optical family name that is specified in the RESERVE or RELEASE statement must be either a character string, or a host or procedural variable that evaluates to a character string. If you specified a character string, check that you enclosed it in quotes.

Oninit® Troubleshooting Guidance

Reasons / Common Causes

-642 fires when a RESERVE/RELEASE statement's family name isn't a character string (or a host/procedural variable evaluating to one) — per the official guidance, an unquoted identifier or a non-string value in that position triggers this error.

An unquoted family name, per the official guidance's specific suggested check — the name needs to be enclosed in quotes to be recognized as a character-string literal.
A host or procedural variable of the wrong type passed where the family name is expected, per the official guidance — it must evaluate to a character string.

Solutions / Resolution

Check that a character-string family name is enclosed in quotes, per the official guidance, if a literal was intended.
Confirm a host/procedural variable used for the family name is character-string typed, per the official guidance, if a variable was used instead of a literal.

Examples

An unquoted family name

RESERVE family optical_family1;
-- -642: optical_family1 needs quotes to be a character-string literal

Corrected

RESERVE family 'optical_family1';

A variable of the wrong type

DEFINE v_family INT;  -- wrong type
RESERVE family :v_family;
-- -642: v_family must be a character-string type

Diagnostic Checks

Check whether the family name is a quoted character-string literal, or, if a variable, that its declared type is character-string.

Related Errors / Related Topics

-641 — "Cannot reserve/release family on non-optical media." A related RESERVE/RELEASE error, about what the name refers to rather than its syntax/type.

A syntax/type issue, not a naming issue — check for missing quotes or a wrongly-typed variable.