# 2200F — zero_length_character_string

> Source-backed reference for PostgreSQL SQLSTATE 2200F.
---

# 2200F

## At a glance {#at-a-glance}
The condition identifies an operation that rejects an empty character string. In the fixed `fuzzystrmatch` path, `metaphone` returns empty text immediately for empty input; only after that early return does it read `reqlen`, and a non-positive requested output length raises `output cannot be empty string`. A separate core `array_to_tsvector` path rejects an empty lexeme, so the message and function matter.

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

| Field | Value |
| --- | --- |
| SQLSTATE | `2200F` |
| Condition | `zero_length_character_string` |
| 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_ZERO_LENGTH_CHARACTER_STRING` |
| Aliases | `—` |

<!-- source facts: data/errcodes/2200F.json -->
<!-- END SQLSTATE FACTS -->

## Meaning {#meaning}
This condition is reserved for an operation whose contract does not permit an empty character string. The fixed paths have different guards: `metaphone(text, reqlen)` first returns empty text when its input text is empty; after that early return, a non-positive `reqlen` on non-empty input raises 2200F. `array_to_tsvector(text[])` independently rejects an element whose length is zero. Neither path proves that every empty SQL string is a 2200F error.

## Messages {#messages}

The `metaphone` guard raises `ERROR` with primary `output cannot be empty string`. The `array_to_tsvector` lexeme guard raises `ERROR` with primary `lexeme array may not contain empty strings`. These paths have no separate DETAIL or HINT in the cited branches.

## Diagnosis {#diagnosis}
If the message names `metaphone`, inspect the supplied text and requested output length: empty input returns an empty result before `reqlen` is checked, while a non-positive length on non-empty input triggers 2200F. If the message names `array_to_tsvector`, inspect every lexeme for an empty string and distinguish NULL lexemes, which use 22004. For a different message, identify the named subsystem first; do not pad arbitrary output merely to silence the condition.

## Response {#response}
Handle the named function’s input requirement explicitly: choose a positive `metaphone` output length for non-empty input, or remove/repair empty lexemes before `array_to_tsvector`. Preserve intended empty input semantics where the function permits them; do not pad data merely to suppress the code.

When this branch raises `ERROR`, an explicit transaction must first be recovered with `ROLLBACK` or `ROLLBACK TO SAVEPOINT` for a savepoint established before the statement; in autocommit, retry only the corrected action after the failed statement completes. See the [transaction and retry guide](../guides/) for this boundary rule.

## Versions {#versions}
The locked catalogue records this condition from 7.4; fixed source coverage is PostgreSQL 18.6.

## Related {#related}
[`22001`](../22001/), [`22000`](../22000/)

## Sources {#sources}
Fixed `metaphone` source: [`fuzzystrmatch.c#L253-287`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/contrib/fuzzystrmatch/fuzzystrmatch.c#L253-L287); the separate core lexeme guard is [`tsvector_op.c#L741-777`](https://github.com/postgres/postgres/blob/724edf9bde9d356724ad384a2e196edc3c9f80f7/src/backend/utils/adt/tsvector_op.c#L741-L777). The structured [evidence record](../data/evidence/2200f.json) retains both messages and scope boundaries. No natural runtime was run; SQLSTATE selection and message text remain the deciding evidence.