PostgreSQL 00000 Error: Causes and Solutions Complete Guide

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PostgreSQL SQLSTATE 00000: Successful Completion

PostgreSQL SQLSTATE 00000 is not an error — it indicates that a query or command completed successfully without any issues. It belongs to SQLSTATE class 00 and serves as the baseline "all good" signal from the database engine. Problems arise when developers mishandle this code in exception blocks or application-level error routing logic.

Top 3 Causes

1. Attempting to CATCH SQLSTATE '00000' in PL/pgSQL

Since 00000 is a success code, it can never be raised as an exception. Trying to catch it in an EXCEPTION block results in dead code that never executes.

-- WRONG: This exception block will NEVER fire for 00000
DO $$
BEGIN
    INSERT INTO payments (id, amount) VALUES (42, 100.00);
EXCEPTION
    WHEN SQLSTATE '00000' THEN
        RAISE NOTICE 'Success!'; -- This line is unreachable
END;
$$;

-- CORRECT: Handle real error conditions only
DO $$
BEGIN
    INSERT INTO payments (id, amount) VALUES (42, 100.00);
    RAISE NOTICE 'Insert succeeded.';
EXCEPTION
    WHEN unique_violation THEN
        RAISE WARNING 'Duplicate ID: %', SQLERRM;
    WHEN others THEN
        RAISE EXCEPTION 'Unexpected error: % [%]', SQLERRM, SQLSTATE;
END;
$$;

2. Misreading SQLSTATE in Application Drivers

Legacy application code sometimes checks SQLSTATE as a plain string and mistakenly treats '00000' as an error pattern, triggering unnecessary rollbacks or retries.

-- Function that explicitly returns SQLSTATE for the application layer
CREATE OR REPLACE FUNCTION safe_insert_user(
    p_user_id INTEGER,
    p_email   TEXT
)
RETURNS TABLE(ok BOOLEAN, code TEXT, msg TEXT)
LANGUAGE plpgsql AS $$
DECLARE
    v_state TEXT;
    v_msg   TEXT;
BEGIN
    INSERT INTO users (user_id, email) VALUES (p_user_id, p_email);
    -- Return explicit success signal
    RETURN QUERY SELECT TRUE, '00000'::TEXT, 'User created successfully.'::TEXT;
EXCEPTION
    WHEN unique_violation THEN
        GET STACKED DIAGNOSTICS v_state = RETURNED_SQLSTATE, v_msg = MESSAGE_TEXT;
        RETURN QUERY SELECT FALSE, v_state::TEXT, v_msg::TEXT;
    WHEN others THEN
        GET STACKED DIAGNOSTICS v_state = RETURNED_SQLSTATE, v_msg = MESSAGE_TEXT;
        RETURN QUERY SELECT FALSE, v_state::TEXT, v_msg::TEXT;
END;
$$;

-- Call and check result in application
SELECT * FROM safe_insert_user(1, 'user@example.com');

3. Batch Jobs Not Logging SQLSTATE Outcomes Properly

In ETL pipelines and batch procedures, failing to distinguish between 00000 (success) and actual error states leads to silent failures or false alerts.

-- Audit log table for batch jobs
CREATE TABLE IF NOT EXISTS job_audit (
    id           SERIAL PRIMARY KEY,
    job_name     TEXT        NOT NULL,
    ran_at       TIMESTAMPTZ DEFAULT NOW(),
    succeeded    BOOLEAN     NOT NULL,
    sqlstate     TEXT,
    detail       TEXT,
    rows_changed INTEGER     DEFAULT 0
);

-- Batch procedure with proper SQLSTATE logging
CREATE OR REPLACE PROCEDURE archive_old_orders()
LANGUAGE plpgsql AS $$
DECLARE
    v_count    INTEGER;
    v_state    TEXT;
    v_msg      TEXT;
BEGIN
    WITH moved AS (
        DELETE FROM orders
        WHERE  created_at < NOW() - INTERVAL '1 year'
          AND  status = 'CLOSED'
        RETURNING *
    ),
    inserted AS (
        INSERT INTO orders_archive SELECT * FROM moved
        RETURNING order_id
    )
    SELECT COUNT(*) INTO v_count FROM inserted;

    INSERT INTO job_audit (job_name, succeeded, sqlstate, detail, rows_changed)
    VALUES ('archive_old_orders', TRUE, '00000', 'Archival complete', v_count);

    COMMIT;
EXCEPTION
    WHEN others THEN
        GET STACKED DIAGNOSTICS v_state = RETURNED_SQLSTATE, v_msg = MESSAGE_TEXT;
        INSERT INTO job_audit (job_name, succeeded, sqlstate, detail)
        VALUES ('archive_old_orders', FALSE, v_state, v_msg);
        ROLLBACK;
        RAISE;
END;
$$;

CALL archive_old_orders();

Quick Fix Solutions

Remove any WHEN SQLSTATE '00000' clauses from exception blocks — they are unreachable and indicate a misunderstanding of PostgreSQL's error model.
Use GET STACKED DIAGNOSTICS inside EXCEPTION blocks to capture the real SQLSTATE and message text for logging.
Return structured results from functions (success flag + SQLSTATE + message) so application drivers don't need to parse raw SQLSTATE strings.

Prevention Tips

Standardize error handling templates. Create a team-wide PL/pgSQL function template that always uses GET STACKED DIAGNOSTICS and writes to a central audit log. Include a code review checklist item: "No success codes in EXCEPTION blocks."
Automate testing with pgTAP. Use pgTAP to write unit tests that verify both the happy path (00000) and error paths of your stored procedures. Integrate these tests into your CI/CD pipeline to catch bad exception-handling logic before deployment.

-- Example pgTAP test for verifying success path
SELECT plan(2);

SELECT lives_ok(
    $$ SELECT safe_insert_user(999, 'test@example.com') $$,
    'safe_insert_user should not throw'
);

SELECT results_eq(
    $$ SELECT code FROM safe_insert_user(999, 'test@example.com') $$,
    $$ VALUES ('00000') $$,
    'Should return SQLSTATE 00000 on success'
);

SELECT * FROM finish();

Related Error Codes

SQLSTATE	Name	Notes
`01000`	Warning	Success with a warning message attached
`02000`	No Data	Query succeeded but returned no rows
`P0001`	Raise Exception	User-defined exception via `RAISE EXCEPTION`
`40001`	Serialization Failure	Concurrent transaction conflict; retry needed

📖 Want a more detailed guide?
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