Informix Error -543

Reasons / Common Causes

-543 fires when a LIKE ... ESCAPE 'char' clause's escape character specification contains more than a single byte.

1. A multi-character string literal given as the escape character — for example, ESCAPE '\\' versus an accidental ESCAPE '\\\\' where quoting doubled the backslash into two characters.
2. A multi-byte character used as the escape character on a database using a multi-byte code set, where a single logical character occupies more than one byte.
3. A copy-paste or string-building bug in generated SQL that concatenated more than one character into the ESCAPE clause's literal.

Solutions / Resolution

1. Review the punctuation of the ESCAPE clause, per the official guidance, and revise it to specify exactly one byte.
2. Pick a single-byte character not otherwise meaningful in the pattern, commonly \ or !, as the escape character.
3. On a multi-byte code set, choose an escape character from the single-byte (ASCII) range, since the limit is one byte, not one logical character.

Examples

Too many characters

SELECT * FROM products WHERE code LIKE '50\%%' ESCAPE '\\';
-- -543: '\\' as a string literal is two characters/bytes

Corrected

SELECT * FROM products WHERE code LIKE '50\%%' ESCAPE '\';

Diagnostic Checks

1. Check the byte length of the literal passed to ESCAPE — a single quoted character should be exactly one byte; anything longer needs revising.

Related Errors / Related Topics

No closely related error codes are cross-referenced for -543 in this set yet.

A one-byte-only limit on the LIKE...ESCAPE character — check the literal's actual byte length, not just how many characters it looks like in the source.