cakephp - 检查 CakePHP3.5 中是否存在记录

Question

以下代码仅返回错误:在表“用户”中找不到记录

if($this->Users->get($uid)->isEmpty()) {
            //do something
        }

因为表是空的，如果表是空的，我想自定义这个，并在浏览器中调用一个新页面

Answer 1

Table::get()将立即评估查询并返回一个实体，或者如果具有给定主键的记录不存在则抛出异常，即它不返回查询，您不能调用 isEmpty()结果上。

如果您正在使用 Table::get()你可以 catch RecordNotFoundException :

try {
    $user = $this->Users->get($uid);
    // ...
} catch (\Cake\Datasource\Exception\RecordNotFoundException $exeption) {
    // record doesn't exist
}

如果您想使用 isEmpty() ，您需要使用常规查询:

$query = $this->Users->findById($uid);
if ($query->isEmpty()) {
    // record doesn't exist
}

如果您实际上不需要结果，可以使用 Table::exists() :

$exists = $this->Users->exists(['id' => $uid]);
if ($exists !== true) {
    // record doesn't exist
}

或 COUNT询问:

$count = $this->Users->findById($uid)->count();
if ($count !== 1) {
    // record doesn't exist
}

也可以看看

Cookbook > Database Access & ORM > Retrieving Data & Results Sets > Getting a Single Entity by Primary Key

Cookbook > Database Access & ORM > Retrieving Data & Results Sets > Checking if a Query or ResultSet is Empty

API > \Cake\Datasource\RepositoryInterface::exists()

Cookbook > Database Access & ORM > Query Builder > Returning the Total Count of Records