PHP MySQL删除数据

通过PHP函数mysqli_query执行SQL DELETE语句，可以从MySQL表中删除数据。下面是将删除test表记录的简单示例。要删除任何表中的记录，需要使用条件子句查找该记录。下面的示例使用主键来匹配test表中的记录。

<html>
   
   <head>
      <title>Delete a Record from MySQL Database</title>
   </head>
   
   <body>
      <?php
         if(isset($_POST['delete'])) {
            $dbhost = 'localhost';
            $dbuser = 'root';
            $dbpass = 'rootpassword';
            $conn = mysql_connect($dbhost, $dbuser, $dbpass);
            
            if(! $conn ) {
               die('Could not connect: ' . mysql_error());
            }
                                
            $emp_id = $_POST['emp_id'];
            
            $sql = "DELETE FROM employee WHERE emp_id = $emp_id" ;
            mysql_select_db('test_db');
            $retval = mysql_query( $sql, $conn );
            
            if(! $retval ) {
               die('Could not delete data: ' . mysql_error());
            }
            
            echo "Deleted data successfully\n";
            
            mysql_close($conn);
         }else {
            ?>
               <form method = "post" action = "<?php $_PHP_SELF ?>">
                  <table width = "400" border = "0" cellspacing = "1" 
                     cellpadding = "2">
                     
                     <tr>
                        <td width = "100">Employee ID</td>
                        <td><input name = "emp_id" type = "text" 
                           id = "emp_id"></td>
                     </tr>
                     
                     <tr>
                        <td width = "100"> </td>
                        <td> </td>
                     </tr>
                     
                     <tr>
                        <td width = "100"> </td>
                        <td>
                           <input name = "delete" type = "submit" 
                              id = "delete" value = "Delete">
                        </td>
                     </tr>
                     
                  </table>
               </form>
            <?php
         }
      ?>
      
   </body>
</html>