Empty body on update generates an MySQL error

[A-Corregidor]

Steps to reproduce

Generate a new project (ex: loopback example todo-list), change DB from memory objecto to MySQL, create MySQL database and config connector. Seed database with some data.

Make a PATCH request that uses updateById repository's method, with an empty body (ex: updatebyId(existingId, {}).

Current Behavior

Query fails with an SQL syntax error: "Error: ER_PARSE_ERROR: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'WHERE id='3db97b64-a616-11ec-8940-0db8a28d8117'".

This error does not occur when using a memory database.

Query sent to DB (without params) is: "UPDATE ModelA SET WHERE id=?"

Expected Behavior

A - No query should be sent to DB B - Send correct (but useless) query to DB

[A-Corregidor]

Up!

[Habbiton]

Up!