0Z002ERRORTier 3 — Handle with care✅ HIGH confidence

stacked diagnostics accessed without active handler

Category: Diagnostics ExceptionVersions: All Postgres versions

What this means

SQLSTATE 0Z002 is raised when GET STACKED DIAGNOSTICS is used outside of an exception handler in PL/pgSQL. Stacked diagnostics are only available inside EXCEPTION blocks where there is an active error being handled.

Why it happens

1Calling GET STACKED DIAGNOSTICS outside of a PL/pgSQL EXCEPTION block

How to reproduce

GET STACKED DIAGNOSTICS used in normal (non-exception) flow.

trigger — this will ERROR

DO $
DECLARE msg TEXT;
BEGIN
  GET STACKED DIAGNOSTICS msg = MESSAGE_TEXT; -- not inside EXCEPTION block
END $;

ERROR: stacked diagnostics accessed without active handler

Fix 1: Move GET STACKED DIAGNOSTICS inside an EXCEPTION block

When inspecting error details from within PL/pgSQL.

fix

DO $
DECLARE msg TEXT;
BEGIN
  -- some statement
EXCEPTION WHEN OTHERS THEN
  GET STACKED DIAGNOSTICS msg = MESSAGE_TEXT;
  RAISE NOTICE 'Error: %', msg;
END $;

Why this works

Stacked diagnostics are populated only when an exception is being handled. They must be accessed inside the EXCEPTION block.

Sources

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

📚 Feature docs: https://www.postgresql.org/docs/current/plpgsql-control-structures.html#PLPGSQL-ERROR-TRAPPING

🔧 Source ref: Class 0Z — Diagnostics Exception

Confidence assessment

✅ HIGH confidence

Standard SQLSTATE. Behaviour well-documented in PL/pgSQL error trapping docs.