3157
MariaDBERRORNotableJSONHIGH confidence
Invalid JSON type
Production Risk
Medium — query fails at runtime on invalid JSON data.
What this means
A JSON function received a value of an unsupported or invalid JSON type. MySQL JSON functions expect properly typed JSON values and will error on mismatches.
Why it happens
- 1Passing a non-JSON value to a function that requires a specific JSON type.
- 2Using JSON_TYPE() on a malformed or NULL JSON document.
How to reproduce
trigger — this will error
trigger — this will error
SELECT JSON_TYPE('not valid json');expected output
ERROR 3157 (HY000): Invalid JSON type: 'not valid json'.
Fix
Validate JSON before passing to JSON functions
Validate JSON before passing to JSON functions
SELECT IF(JSON_VALID(col), JSON_TYPE(col), NULL) FROM t1;
Why this works
JSON_VALID() pre-checks the document, preventing type errors.
What not to do
✕
Sources
Official documentation ↗
MySQL 8.0 — 3157 ER_INVALID_JSON_TYPE
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