关于php:PHP如何使用mysqlirealescapestring函数用法示例

mysqli_real_escape_string()函数是PHP中的内置函数, 用于本义所有特殊字符以用于SQL查问。在将字符串插入数据库之前应用它, 因为它删除了可能烦扰查问操作的任何特殊字符。

当应用简略的字符串时, 它们中可能蕴含特殊字符, 例如反斜杠和撇号(尤其是当它们间接从输出了此类数据的表单中获取数据时)。这些被认为是查问字符串的一部分, 并且会烦扰其失常运行。

<?php
  
$connection = mysqli_connect(
     "localhost" , "root" , "" , "Persons" ); 
         
// Check connection 
if (mysqli_connect_errno()) { 
     echo "Database connection failed." ; 
} 
   
$firstname = "Robert'O" ;
$lastname = "O'Connell" ;
   
$sql ="INSERT INTO Persons (FirstName, LastName) 
             VALUES ( '$firstname' , '$lastname' )";
   
   
if (mysqli_query( $connection , $sql )) {
      
     // Print the number of rows inserted in
     // the table, if insertion is successful
     printf( "%d row inserted.n" , $mysqli ->affected_rows);
}
else {
      
     // Query fails because the apostrophe in 
     // the string interferes with the query
     printf( "An error occurred!" );
}
   
?>

在下面的代码中, 查问失败, 因为应用mysqli_query()执行撇号时, 会将撇号视为查问的一部分。解决方案是在查问中应用字符串之前应用mysqli_real_escape_string()。

<?php
   
$connection = mysqli_connect(
         "localhost" , "root" , "" , "Persons" ); 
  
// Check connection 
if (mysqli_connect_errno()) { 
     echo "Database connection failed." ; 
} 
       
$firstname = "Robert'O" ;
$lastname = "O'Connell" ;
   
// Remove the special characters from the
// string using mysqli_real_escape_string
   
$lastname_escape = mysqli_real_escape_string(
                     $connection , $lastname );
                      
$firstname_escape = mysqli_real_escape_string(
                     $connection , $firstname );
   
$sql ="INSERT INTO Persons (FirstName, LastName)
             VALUES ( '$firstname' , '$lastname' )";
  
if (mysqli_query( $connection , $sql )) {
      
     // Print the number of rows inserted in
     // the table, if insertion is successful
     printf( "%d row inserted.n" , $mysqli ->affected_rows);
}
   
?>

输入如下：

1 row inserted.

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