42P14ERRORTier 2 — Caution✅ HIGH confidence

invalid prepared statement definition

Category: Syntax Error or Access Rule ViolationVersions: All Postgres versions

What this means

SQLSTATE 42P14 is raised when a PREPARE statement contains a query that cannot be prepared — for example, a multi-statement string or a statement type that does not support parameters.

Why it happens

1Preparing a statement that contains multiple SQL commands (only one is allowed per PREPARE)
2Preparing a DDL statement type that does not support parameterisation

How to reproduce

PREPARE with a multi-statement body.

trigger — this will ERROR

PREPARE bad_stmt AS SELECT 1; SELECT 2; -- two statements

ERROR: cannot insert multiple commands into a prepared statement

Fix 1: Prepare only a single SQL statement

When using PREPARE/EXECUTE.

fix

PREPARE stmt1 AS SELECT 1;
PREPARE stmt2 AS SELECT 2;

Why this works

PREPARE accepts exactly one SQL statement. Split multi-statement strings into individual PREPARE calls.

Sources

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

🔧 Source ref: Class 42 — Syntax Error or Access Rule Violation (Postgres-specific)

Confidence assessment

✅ HIGH confidence

Postgres-specific. Stable across versions.