Eloquent关系同步也会删除吗？

Question

更新模型并同步关系时,如果我没有传入已存在的所有ID,是否会删除该关系？

Answer 1

您决定:sync具有默认的第二个参数true并负责分离:

$model->relationship()->sync([1,2,3]);

$model->relationship()->sync([4,5,6]); // attached [4,5,6], detached [1,2,3]
$model->relationship()->getRelatedIds(); // [4,5,6]

// but:
$model->relationship()->sync([4,5,6], false); // attached [4,5,6], detached []
$model->relationship()->getRelatedIds(); // [1,2,3,4,5,6]