# 22019 — invalid_escape_character

> Source-backed reference for PostgreSQL SQLSTATE 22019.
---

## At a glance {#at-a-glance}
An operation rejected its escape argument. The fixed catalogue defines `invalid_escape_character`, but the bounded PostgreSQL 18.6 source scan found no native emitter to which one message or severity can safely be attached.

<!-- BEGIN SQLSTATE FACTS: generated by scripts/generate.py; do not edit -->

| Field | Value |
| --- | --- |
| SQLSTATE | `22019` |
| Condition | `invalid_escape_character` |
| Status | `active` |
| Known present by | `7.4` |
| Locked snapshots | `9.0.23, 9.1.24, 9.2.24, 9.3.25, 9.4.26, 9.5.25, 9.6.24, 10.23, 11.22, 12.22, 13.23, 14.24, 15.19, 16.15, 17.11, 18.6, 19beta3` |
| Macros | `ERRCODE_INVALID_ESCAPE_CHARACTER` |
| Aliases | `—` |

<!-- source facts: data/errcodes/22019.json -->
<!-- END SQLSTATE FACTS -->

## Meaning {#meaning}
The relevant rule belongs to the consumer of `ESCAPE`. PostgreSQL's LIKE and SIMILAR documentation permits a one-character escape, allows `ESCAPE ''` to disable escaping, and distinguishes that behavior from the SQL standard's zero-length rule. Another consumer may require one character, reject a character class, or apply its own empty-string rule. Therefore `22019` cannot be explained by one universal length or character check without an emitting path.

## Diagnosis {#diagnosis}
Identify the consumer and read its complete diagnostic before changing the value. Check the escape expression's resolved type and character length, whether the value is an empty string, and whether the chosen character has a special meaning in that pattern language. Keep SQL string-literal quoting separate from pattern escaping, and distinguish this bounded definition from `2200C` SIMILAR separator syntax and `2200D` invalid octets.

## Response {#response}
Use the consumer's documented escape representation: a valid single character where that consumer requires one, or the explicitly supported empty string (ESCAPE '') where it disables escaping. Re-encode the SQL literal as needed, then validate the same consumer; do not apply a LIKE rule to an unrelated parser.

## Versions {#versions}
The locked catalogue records this condition from 7.4; fixed source coverage is PostgreSQL 18.6. The exact implementation introduction date and native emitter remain unresolved by this bounded review.

## Related {#related}
[`2200C`](../2200c/), [`2200D`](../2200d/)

## Sources {#sources}
- The fixed definition is confirmed in `errcodes.txt`; no occurrence of `ERRCODE_INVALID_ESCAPE_CHARACTER` was resolved in the bounded PostgreSQL 18.6 source scan.
- Same-tag [pattern-matching documentation](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/doc/src/sgml/func.sgml#L5551-L5662) documents LIKE's one-character/default/empty escape behavior, and [`#L5724-L5830`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/doc/src/sgml/func.sgml#L5724-L5830) documents the corresponding SIMILAR rules. These are consumer rules, not a claimed `22019` emitter.

Runtime verification is `not_run`; this page does not assert a primary template, severity, or transaction effect. The structured [evidence record](../data/evidence/22019.json) retains the definition, documentation scope, and bounded-emitter limitation.