Update multiple rows with different values in one query

[nandi95]

Would this be possible to implement? It would mean a single query instead of looping over and updating.
It could look something like:

Model::updateMultiple([
    [
        // the primary key name of the model
        'id' => 1,
        // the rest is what should be updated how
        'key' => 'value-for-id-1',
        'key2' => 'value2-for-id-1',
    ],
    [
        // the primary key name of the model
        'id' => 2,
        // the rest is what should be updated how
        'key' => 'value-for-id-2',
        'key2' => 'value2-for-id-2',
    ]
]);

There is a sql CASE statement with WHEN and THEN keywords: tutorial
If possible, what are the limitations? Is there a statement max length?