mysqli_stmt::$affected_rows

mysqli_stmt_affected_rows

(PHP 5)

mysqli_stmt::$affected_rows -- mysqli_stmt_affected_rows — Returns the total number of rows changed, deleted, or inserted by the last executed statement

说明

面向对象风格

int $mysqli_stmt->affected_rows ;

过程化风格

int mysqli_stmt_affected_rows ( mysqli_stmt $stmt )

Returns the number of rows affected by INSERT, UPDATE, or DELETE query.

This function only works with queries which update a table. In order to get the number of rows from a SELECT query, use mysqli_stmt_num_rows() instead.

参数

stmt: 仅以过程化样式：由 mysqli_stmt_init() 返回的 statement 标识。

返回值

An integer greater than zero indicates the number of rows affected or retrieved. Zero indicates that no records where updated for an UPDATE/DELETE statement, no rows matched the WHERE clause in the query or that no query has yet been executed. -1 indicates that the query has returned an error. NULL indicates an invalid argument was supplied to the function.

Note:

If the number of affected rows is greater than maximal PHP int value, the number of affected rows will be returned as a string value.

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();
}

 
 $mysqli -> query ( "CREATE TEMPORARY TABLE myCountry LIKE Country" );

 $query  =  "INSERT INTO myCountry SELECT * FROM Country WHERE Code LIKE ?" ;

 
 if ( $stmt  =  $mysqli -> prepare ( $query )) {

     
     $code  =  'A%' ;
     $stmt -> bind_param ( "s" ,  $code );

     
     $stmt -> execute ();

     printf ( "rows inserted: %d\n" ,  $stmt -> affected_rows );

     
     $stmt -> 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();
}

 
 mysqli_query ( $link ,  "CREATE TEMPORARY TABLE myCountry LIKE Country" );

 $query  =  "INSERT INTO myCountry SELECT * FROM Country WHERE Code LIKE ?" ;

 
 if ( $stmt  =  mysqli_prepare ( $link ,  $query )) {

     
     $code  =  'A%' ;
     mysqli_stmt_bind_param ( $stmt ,  "s" ,  $code );

     
     mysqli_stmt_execute ( $stmt );

     printf ( "rows inserted: %d\n" ,  mysqli_stmt_affected_rows ( $stmt ));

     
     mysqli_stmt_close ( $stmt );
}

 
 mysqli_close ( $link );
 ?>

以上例程会输出：

rows inserted: 17

参见

mysqli_stmt_num_rows() - Return the number of rows in statements result set
mysqli_prepare() - Prepare an SQL statement for execution

用户评论:

[#1] gerbawn at 163 dot com [2015-01-27 06:47:10]

I find should add $stmt->store_result() after $stmt->execute(), otherwise you can't get right results when use $stmt->affected_rows

[#2] Chuck [2007-04-28 22:51:16]

I'm not sure whether or not this is the intended behavior, but I noticed through testing that if you were to use transactions and prepared statements together and you added a single record to a database using a prepared statement, but later rolled it back, mysqli_stmt_affected_rows will still return 1.

[#3] Carl Olsen [2005-12-27 10:34:42]

It appears that an UPDATE prepared statement which contains the same data as that already in the database returns 0 for affected_rows. I was expecting it to return 1, but it must be comparing the input values with the existing values and determining that no UPDATE has occurred.