mysqli_result::fetch_object

mysqli_fetch_object

(PHP 5)

mysqli_result::fetch_object -- mysqli_fetch_object — Returns the current row of a result set as an object

说明

面向对象风格

object mysqli_result::fetch_object ([ string $class_name = "stdClass" [, array $params ]] )

过程化风格

object mysqli_fetch_object ( mysqli_result $result [, string $class_name = "stdClass" [, array $params ]] )

The mysqli_fetch_object() will return the current row result set as an object where the attributes of the object represent the names of the fields found within the result set.

Note that mysqli_fetch_object() sets the properties of the object before calling the object constructor.

参数

result: 仅以过程化样式：由 mysqli_query() ， mysqli_store_result() 或 mysqli_use_result() 返回的结果集标识。
class_name: The name of the class to instantiate, set the properties of and return. If not specified, a stdClass object is returned.
params: An optional array of parameters to pass to the constructor for class_name objects.

返回值

Returns an object with string properties that corresponds to the fetched row or NULL if there are no more rows in resultset.

Note: 此函数返回的字段名大小写敏感。

Note: 此函数将 NULL 字段设置为 PHP NULL 值。

范例

Example #1 面向对象风格

  <?php
$mysqli  = new  mysqli ( "localhost" ,  "my_user" ,  "my_password" ,  "world" );

 
 if ( mysqli_connect_errno ()) {
     printf ( "Connect failed: %s\n" ,  mysqli_connect_error ());
    exit();
}
 
 $query  =  "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 50,5" ;

if ( $result  =  $mysqli -> query ( $query )) {

     
     while ( $obj  =  $result -> fetch_object ()) {
         printf  ( "%s (%s)\n" ,  $obj -> Name ,  $obj -> CountryCode );
    }

     
     $result -> close ();
}

 
 $mysqli -> close ();
 ?>

Example #2 过程化风格

  <?php
$link  =  mysqli_connect ( "localhost" ,  "my_user" ,  "my_password" ,  "world" );

 
 if ( mysqli_connect_errno ()) {
     printf ( "Connect failed: %s\n" ,  mysqli_connect_error ());
    exit();
}

 $query  =  "SELECT Name, CountryCode FROM City ORDER by ID DESC LIMIT 50,5" ;

if ( $result  =  mysqli_query ( $link ,  $query )) {

     
     while ( $obj  =  mysqli_fetch_object ( $result )) {
         printf  ( "%s (%s)\n" ,  $obj -> Name ,  $obj -> CountryCode );
    }

     
     mysqli_free_result ( $result );
}

 
 mysqli_close ( $link );
 ?>

以上例程会输出：

Pueblo (USA)
Arvada (USA)
Cape Coral (USA)
Green Bay (USA)
Santa Clara (USA)

参见

mysqli_fetch_array() - Fetch a result row as an associative, a numeric array, or both
mysqli_fetch_assoc() - Fetch a result row as an associative array
mysqli_fetch_row() - Get a result row as an enumerated array
mysqli_query() - 对数据库执行一次查询
mysqli_data_seek() - Adjusts the result pointer to an arbitrary row in the result

用户评论:

[#1] me at philkershaw dot me [2014-03-28 17:02:09]

As a best practice, if you intend to use a defined class when using fetching_object(). Put the data obtaining code within a static method of the defined class. Otherwise, wherever you include the file (if not using an autoloader) the data connection will occur whether you want it to or not.

For example:

<?php class User { public $name; public static function getUser($id) { $conn = new mysqli('localhost', 'username', 'password', 'database'); if ($result = $conn->query("SELECT * FROM users WHERE id = {$id} LIMIT 1")) { return $result->fetch_object('User'); $result->close(); } } } ?>

Call the static method to obtain an instance of the User class with your data applied to it.

<?php $user = User::getUser('31'); echo $user->name; // echo's 'Phil' ?>

[#2] Driek [2012-06-26 17:18:46]

As indicated in the user comments of the mysql_fetch_object, it is important to realize that class fields get values assigned to them BEFORE the constructor is called.
For example;
<?php class Employee { private $id; public function __construct($id = 0) { $this->id = $id; } } // some code for creating a database connection... i.e. mysqli object .... $result = $con->query("select id, name from employees"); $anEmployee = $result->fetch_object("Employee"); ?>
will result in the ID being 0 because it is overridden by the constructor. Therefore, it is useful to check if the class field is already set.
I.e.
<?php class Employee { private $id; public function __construct($id = 0) { if (!$this->id) { $this->id = $id } } } ?>
Also note that the fields which will be assigned by fetch_object are case sensitive. If your table has the field "ID", it will result in the class field $ID being set. A simple work-around is to use aliases. I.e. "SELECT *, ID as id FROM myTable"
I hope this helps some people.

[#3] Alex [2012-01-27 04:36:32]

Make sure to specify the full namespace for the "string $class_name" parameter and not a partial one, as it won't find it. For example:

<?php namespace Root(backslash)FirstLevel { public static function Test($result) { return mysqli_fetch_object($result, 'SecondLevel\\MyClass'); } } ?>

... will not work but this will:

<?php namespace Root(backslash)FirstLevel { public static function Test($result) { return mysqli_fetch_object($result, 'Root\\FirstLevel\\SecondLevel\\MyClass'); } } ?>

[#4] benpptung at tacol dot biz [2009-08-08 20:04:09]

I don't know why no one talk about this.
fetch_object is very powerful since you can instantiate an Object which has the methods you wanna have.

You can try like this..

<?php class PowerfulVO extends AbstractWhatEver { public $field1; private $field2; // note : private is ok public function method(){ // method in this class } } $sql = "SELECT * FROM table ..." $mysqli = new mysqli(........); $result = $mysqli->query($sql); $vo = $result->fetch_object('PowerfulVO'); ?>

Note : if the field is not defined in the class, fetch_object will add this field for you as public.

The method is very powerful, especially if you want to use a VO design pattern or class mapping feature with Flex Remoting Object( Of course, you need to have ZendAMF or AMFPHP ..framework)

Hope this help and open new possibilities for you

[#5] peterbelm at g[oogle]mail dot com [2008-08-18 07:10:32]

If your SQL code selects columns with empty names like so:

SELECT id as ``...

You will get a fatal error "Cannot access empty property", this took me a while to track down!

Obviously your SQL really shouldn't do that, and should be fixed but I'm going to submit a feature request to ask for a better error message for that.