检查CakePHP3.5中是否存在记录 [英] Check if record exists in CakePHP3.5

问题描述

以下代码仅返回错误：在用户表中找不到记录

The Following Code returns only a error :Record not found in table "users"

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

因为表为空，所以我想自定义表是否为空，并在浏览器中调用新页面

Because the Table is empty, i want to customize this if the table is empty, and call a new page in browser

推荐答案

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正确则抛出异常不存在，即它不返回查询，您不能在结果上调用 isEmpty（）。

Table::get() will immediately evaluate the query and return an entity, or throw an exception if the record with the given primary key doesn't exist, ie it doesn't return a query, you cannot call isEmpty() on the result.

如果您使用的是 Table :: get（），则可以捕获 RecordNotFoundException ：

If you are using Table::get() you can catch the RecordNotFoundException:

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

如果要使用 isEmpty（）， d需要使用常规查询：

If you wanted to use isEmpty(), you'd need to use a regular query:

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

如果实际上不需要结果，则可以使用 Table :: exists（）：

If you don't actually need the result, you can use Table::exists():

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

或 COUNT 查询：

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

另请参见

• Cookbook>数据库访问& ORM>检索数据和结果集>通过主键获取单个实体


• 菜谱>数据库访问& ORM>检索数据和结果集>检查查询或结果集是否为空


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


• 手册>数据库访问和ORM>查询生成器>返回记录总数

• 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

这篇关于检查CakePHP3.5中是否存在记录的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！