42P13

At a glance

42P13 (invalid_function_definition) Function, aggregate, and trigger declarations can fail validation before execution.

Meaning

Function-definition validation uses this condition for incompatible declarations. Selected core paths cover a polymorphic aggregate transition type that cannot be determined (with a caller-generated internal DETAIL), a function return-type mismatch when the final statement is not a compatible SELECT or DML RETURNING, and trigger functions declaring arguments.

Diagnosis

Classify the message before editing the function: aggregate transition-type inference and its dynamic DETAIL, final statement/RETURNING result versus declared return type, or trigger argument declaration. Compare the stored signature and return type with the body and the trigger contract; a non-returning DML statement or utility command is a different final-statement failure from a bad scalar coercion.

Response

Correct the declaration or body that the message identifies. Supply a determinable aggregate transition type, make the final function statement return the declared type, and read trigger arguments through TG_NARGS/TG_ARGV instead of declaring them. Recreate or replace only after checking dependent callers. If an ERROR is raised inside an explicit transaction, ROLLBACK or ROLLBACK TO a pre-error savepoint before issuing another DDL command.

Messages

Representative source messages include: message: cannot determine transition data type; errdetail_internal: %s; message: return type mismatch in function declared to return %s; DETAIL: Function's final statement must be SELECT or INSERT/UPDATE/DELETE/MERGE RETURNING.; message: trigger functions cannot have declared arguments; HINT: The arguments of the trigger can be accessed through TG_NARGS and TG_ARGV instead.. Placeholders are filled by the actual object, column, or parameter.

Versions

The locked catalogue shows this condition by PostgreSQL 7.4; behavior here is fixed to PostgreSQL 18.6 source. Catalogue presence is a range boundary, not proof that every message or feature began in that release.

Related

• 42P18
• 42804

Sources

Source messages, line anchors, and evidence limits are recorded in authored evidence.

• src/backend/catalog/pg_aggregate.c:142-145 (fixed source)
• src/backend/executor/functions.c:2222-2226 (fixed source)
• src/pl/plpgsql/src/pl_comp.c:493-496 (fixed source)

Source evidence

Evidence belongs to the frozen source and runtime versions listed here. It is not a runtime verification of the selected manual version.

• src/backend/utils/errcodes.txt · REL_18_6 · line 394
  724edf9bde9d356724ad384a2e196edc3c9f80f7
• src/backend/catalog/pg_aggregate.c · REL_18_6 · lines 142-145
  724edf9bde9d356724ad384a2e196edc3c9f80f7
• src/backend/executor/functions.c · REL_18_6 · lines 2222-2226
  724edf9bde9d356724ad384a2e196edc3c9f80f7
• src/pl/plpgsql/src/pl_comp.c · REL_18_6 · lines 493-496
  724edf9bde9d356724ad384a2e196edc3c9f80f7
• raw/calls/REL_18_6.jsonl · ·

Message templates

cannot determine transition data type

%s

%s

return type mismatch in function declared to return %s

Function's final statement must be SELECT or INSERT/UPDATE/DELETE/MERGE RETURNING.

Function's final statement must be SELECT or INSERT/UPDATE/DELETE/MERGE RETURNING.

trigger functions cannot have declared arguments

The arguments of the trigger can be accessed through TG_NARGS and TG_ARGV instead.

The arguments of the trigger can be accessed through TG_NARGS and TG_ARGV instead.

Reproduction & repair cases

No reproduction case is attached to this condition.

Recorded runtime evidence

No runtime observation is attached to this entry.