SQLSTATE 42883 ERROR Class 42: Syntax Error or Access Rule Violation

undefined_function operator does not exist: … = … — 42883

PostgreSQL error "operator does not exist: … = …" (SQLSTATE 42883): what it means, common causes, and how to fix it.

PG 12, 13, 14, 15, 16, 17, 18 Official docs
Last reviewed May 2025 Grounded in source

Diagnostic Queries

Symptoms

An expression used an operator with operand types for which no matching operator exists (and no implicit cast bridges them). PostgreSQL raises SQLSTATE 42883 (undefined_function).

  • The message shows the operator and operand types (e.g. integer = text).
  • A HINT suggests adding explicit casts.
  • Common when comparing columns of different types.

What the server log shows

ERROR:  operator does not exist: integer = text
HINT:  No operator matches the given name and argument types. You might need to add explicit type casts.

Why PostgreSQL raises this — what the manual says

As Section 10.2 Operators explains:

The operand types supplied to the operator have no matching operator definition and cannot be implicitly converted to one; cast the operands to compatible types so a single operator can be resolved.

Operator resolution looks for an operator matching the name and operand types, possibly via implicit casts. When neither an exact operator nor a cast path exists, PostgreSQL reports 42883.

Common causes

  • Comparing or operating on mismatched types (e.g. integer vs text).
  • A removed/changed implicit cast across versions.
  • Calling an operator on a type that doesn’t define it.

How to fix it

  1. Add explicit casts to a common type (e.g. id = $1::integer).
  2. Bind parameters with the correct type in the driver.
  3. Define the operator/cast if you need it for custom types.

Related & next steps

Reference: PostgreSQL 18 Section 10.2 “Operators”.

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