null_value_not_allowed Null Value Not Allowed — SQLSTATE 22004

A NULL value was supplied where a non-null value is required.

• The error is written to the server log and returned to the client carrying SQLSTATE 22004.
• Any driver (libpq, JDBC, psycopg, npgsql, pgx) surfaces this code in its error object so you can branch on it programmatically.
• PL/pgSQL can trap it by name: EXCEPTION WHEN null_value_not_allowed THEN.

Severity: ERROR  |  PostgreSQL versions: 12, 13, 14, 15, 16, 17

Reproduce with the exact statement and read the full message in the server log (raise log_min_messages / set log_min_error_statement for more context).

A function argument or assignment received NULL but the context does not allow it.

Steps to resolve 22004:

1. Provide a non-null value, or default it with COALESCE(value, fallback).
2. Validate inputs before the call.

Reference: PostgreSQL error codes — Class 22 (Data Exception).