Calling save on a model for which no changes have been made generates invalid sql

[dob9601]

Description

Calling save on a model for which no changes have been made generates invalid sql which causes an unclear error message.

Tested against MariaDB, but have reason to believe it should occur with all database backends

This behaviour seems to be originating from within the Update::one() method

Steps to Reproduce

let db = Database::connect("mysql://some_connection_url").await.unwrap();

// UserActive in this case is an alias to an ActiveModel
let user = UserActive { ... }
user.insert(&db).await.unwrap()

// Some quantity of code that may or may not change the user.

let active_user: UserActive = user.into();

active_user.save(&db).await.unwrap();

Expected Behavior

Either a clearer error message stating that the model hasn't changed - thus save cannot be called or no error at all and the call to save to be a no-op

Actual Behavior

Raises:

You have an error in your SQL syntax; check the manual that corresponds to your MariaDB server version for the right syntax to use near 'WHERE `users`.`id` = ?' at line 1"

Reproduces How Often

100%

Versions

MariaDB: Ver 15.1 Distrib 10.9.4-MariaDB, for Linux (x86_64) using readline 5.1
sea-orm: 0.10.5

Additional Information

[tyt2y3]

This is a duplicate to #1376