no_data_found query returned no rows — P0002

Symptoms

A PL/pgSQL SELECT … INTO STRICT returned no rows. PostgreSQL raises SQLSTATE P0002 (no_data_found).

• A STRICT INTO query found zero rows.
• STRICT requires exactly one row.
• Common when the lookup key doesn’t match.

What the server log shows

ERROR:  query returned no rows
CONTEXT:  PL/pgSQL function get_user(integer) line 5 at SQL statement

Why PostgreSQL raises this — what the manual says

Section 41.5.3 Executing a Command with a Single-Row Result:

“If the STRICT option is specified, the command must return exactly one row or a run-time error will be reported, either NO_DATA_FOUND (no rows) or TOO_MANY_ROWS (more than one row).”

With INTO STRICT, PL/pgSQL requires exactly one result row. When the query returns none, it raises P0002 so the missing-data case is handled explicitly.

Common causes

• The lookup key matched no rows.
• Filtering criteria excluded all rows.
• Expecting a row that was deleted/never inserted.

How to fix it

1. Handle the case with an EXCEPTION WHEN NO_DATA_FOUND block.
2. Use non-STRICT INTO and check NOT FOUND if zero rows is valid.
3. Verify the lookup key exists before the STRICT query.

Related & next steps

• SQLSTATE P0002 — No Data Found (full reference)
• Message: query returned more than one row
• Glossary: PL/pgSQL

Reference: PostgreSQL 18 Section 43.5 “Basic Statements”.