MongoDB findOne不返回任何东西 [英] MongoDB findOne not returning anything

问题描述

根据PHP的mongo页面findOne，这应该工作正常，但它不是。

  $ email = array 'email'=> $ _POST ['email']; 
 $ conn = new MongoClient（mongodb：// localhost：27017 /）; 
 $ xyz = $ conn-> > users; 
 $ cursor = $ xyz-> findOne（$ email）; 
 print_r（$ cursor）; 
   
 
当使用find方法而不是findOne时，这是工作。
  $ email = array（'email'=> $ _ POST ['email']）; 
 $ pass = $ _POST ['password']; 
 $ conn = new MongoClient（'localhost'）; 
 $ db = $ conn-> database; 
 $ collection = new MongoCollection（$ db，'users'）; 
 $ cursor = $ collection-> find（$ email）; 
 
 foreach（$ cursor as $ obj）{
 $ test = $ obj ['email']; 
 print_r（$ test）;} 
  
解决方案
 
 p> findOne（）不返回像find（）这样的游标 - 请在这里检查文档：
 
 
 
  http://www.php.net//manual/en/mongocollection.findone.php  
 
 
 
此外，你的代码中似乎有一个语法错误，你在第一行缺少一个右括号。此外，使用名为$ cursor的变量，当它不返回光标往往是一个坏主意，因为它导致混乱的那些查看代码。最后，你在两个代码示例之间使用不同的方法 - 不同的变量名，不同的字符串传递给MongoClient（），一个使用对MongoCollection（）的调用，一个
 
 
 
考虑到所有这一切，我会提出以下建议：
 ＃Add right）
 $ email = array（'email'=> $ _POST ['email']） ; 
 $ conn = new MongoClient（mongodb：// localhost：27017 /）; 
 $ db = $ conn-> database; 
 $ collection = new MongoCollection（$ db，'users'）; 
 $ findoneResult = $ collection-> findOne（$ email）; 
 print_r（$ findOneResult）; 
  
 
According to the PHP mongo page for findOne, this should be working fine but its not.
$email = array('email' => $_POST['email'];
$conn = new MongoClient("mongodb://localhost:27017/");
$xyz = $conn->database->users;
$cursor = $xyz->findOne($email); 
print_r ($cursor);
This is working when using the find method instead of findOne.
$email = array('email'=>$_POST['email']);
        $pass = $_POST['password'];
        $conn = new MongoClient( 'localhost' );
        $db = $conn->database;
        $collection = new MongoCollection($db, 'users');
        $cursor = $collection->find($email); 

        foreach ($cursor as $obj){
            $test = $obj['email'];
                    print_r($test); }
Can someone explain why this is happening ?
解决方案
findOne() does not return a cursor like find() does - please check the documentation here:

http://www.php.net//manual/en/mongocollection.findone.php

In addition you appear to have a syntax error in your code, you are missing a right parentheses in the first line. Also, using variables named "$cursor" when it's not returning a cursor tends to be a bad idea as it causes confusion for those viewing the code. 

Finally, you are using different approaches between your two code samples - different variable names, different strings passed to MongoClient(), one uses a call to MongoCollection() and one does not, etc - very easy for problems to crop up in those differences.

Taking all that into account, I'd propose the following:
# Add right ) at end of following statement
$email = array('email' => $_POST['email']);
$conn = new MongoClient("mongodb://localhost:27017/");
$db = $conn->database;
$collection = new MongoCollection($db, 'users');
$findoneResult = $collection->findOne($email); 
print_r ($findOneResult);


                        
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