Diagnostics Exception — SQLSTATE 0Z000

SQLSTATE 0Z000 condition diagnostics_exception class 0Z — Diagnostics Exception severity ERROR
Reproduced & verified on PostgreSQL 14.23, 15.18, 16.14, 17.10 and 18.4 — identical message on every version.
Last reviewed 29 May 2025 · Reproduced live with the SQL on this page.

! Symptoms Free

The server reports SQLSTATE 0Z000 (diagnostics_exception), a condition in the Diagnostics Exception class.

  • The error is written to the server log and returned to the client carrying SQLSTATE 0Z000.
  • 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 diagnostics_exception THEN.

1 Environment & reproduce Free

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).

? Root cause Free

0Z000 belongs to Class 0Z — Diagnostics Exception. In this class, stacked diagnostics were accessed without an active handler.

The first two characters (0Z) identify the error class, so application code can match the whole class via 0Z000 when the specific code is not needed.

3 Recovery & verify Free

Only use GET STACKED DIAGNOSTICS inside a PL/pgSQL EXCEPTION handler.

Reference: PostgreSQL error codes — Class 0Z (Diagnostics Exception).