2F004ERRORTier 2 — Caution✅ HIGH confidence

reading SQL data not permitted

Category: SQL Routine ExceptionVersions: All Postgres versions

What this means

SQLSTATE 2F004 is raised when a SQL function declared as NO SQL or CONTAINS SQL (without read data permission) attempts to execute a SELECT or other read statement.

Why it happens

1A SQL function with NO SQL or inappropriate data access attribute attempts to read data with a SELECT

How to reproduce

Function with NO SQL attempting a SELECT.

trigger — this will ERROR

ERROR: reading SQL-data not permitted

Fix 1: Change the function attribute to READS SQL DATA or CONTAINS SQL

When the function needs to read data.

fix

CREATE OR REPLACE FUNCTION my_fn() RETURNS INT
LANGUAGE SQL
READS SQL DATA
AS $ SELECT COUNT(*) FROM orders; $;

Why this works

READS SQL DATA permits SELECT statements in the function body.

Sources

📚 Official docs: https://www.postgresql.org/docs/current/errcodes-appendix.html

🔧 Source ref: Class 2F — SQL Routine Exception

Confidence assessment

✅ HIGH confidence

Standard SQLSTATE. Stable across versions.