Informix Error -1278: Invalid escape sequence.

Reasons / Common Causes

-1278 fires when an invalid escape sequence appears in a LIKE/MATCHES clause on an ANSI database — per the official guidance, only specific characters can be escaped: %, _, and the escape character itself for LIKE; *, ?, [, ], and the escape character itself for MATCHES.

1. A LIKE clause escaping a character other than %, _, or the escape character itself, per the official guidance — the direct, common cause.
2. A MATCHES clause escaping a character other than *, ?, [, ], or the escape character itself, per the official guidance — the other direct, common cause.

Solutions / Resolution

1. Review the pattern-matching string to ensure only valid characters are being escaped, per the official guidance — matching the clause type (LIKE vs. MATCHES) to its own specific escapable-character set.

Examples

An invalid LIKE escape

SELECT * FROM orders WHERE status LIKE '50\%' ESCAPE '\';
-- valid: % is escapable in LIKE
SELECT * FROM orders WHERE status LIKE 'a\b' ESCAPE '\';
-- -1278: 'b' is not an escapable character in LIKE

Diagnostic Checks

1. Check every escaped character in the LIKE/MATCHES pattern against that clause type's specific set of valid escapable characters.

Related Errors / Related Topics

• -1279 — "Value exceeds string column length." A related ANSI-database error, about column length rather than pattern-matching escape sequences.

An escape sequence used a character not valid for that clause type (LIKE vs. MATCHES) — check the pattern against the correct escapable-character set.