How to solve the problem of Chinese in sql query statement in php

In PHP programming, when using SQL statements for database queries, you may encounter problems with Chinese characters. This situation, if not handled correctly, can lead to errors or exceptions in the query. So, how to correctly handle Chinese characters in query statements in PHP?

1. Compatibility issues with Chinese characters

In the traditional GB2312 encoding environment, Chinese characters generally do not have problems in query statements. However, in the UTF-8 encoding environment, because Chinese characters occupy different numbers of bytes, special processing is required.

In PHP, the mysql_query function is often used to execute SQL query statements. This function contains an optional parameter charset, which is used to specify the character set. If not set, MySQL defaults to latin1.

If the query contains Chinese characters, you need to set the charset to utf8 to ensure the consistency of the character set. Otherwise, the query results will be garbled.

2. Solutions

In response to the above problems, some solutions can be adopted:

1. Set the character set

Before executing the query operation, you can First execute the following command to set the connection character set

$conn = mysql_connect($server, $user, $pass);
mysql_select_db($database, $conn);
mysql_query(" set names utf8", $conn);

2. Convert character set

After connecting to the database, transcode the Chinese characters in the query statement to ensure the correct display of the query results.

$chinese = iconv("gb2312", "utf-8", $chinese);

3. Use PDO to operate the database

PDO is the abbreviation of PHP Data Objects . It is an object-oriented database operation module that supports multiple database types. When using PDO to operate the database, you can set the database connection character set in the following way:

$dbh = new PDO('mysql:host=localhost;dbname=testdb;charset=utf8', 'username', ' password', array(

PDO::ATTR_PERSISTENT => true

));

Since manual transcoding is not required when using PDO, it is easier to prevent SQL injection attacks.

4. Use mysqli extension

Mysqli extension is an extension provided after PHP5.0 version to operate MySQL database. When using the mysqli_query function in the mysqli extension for query operations, you can set the connection character set in the following way:

mysqli_query("set names 'utf8'");

Conclusion:

For the problem of Chinese characters in the query statement, we can use the above method to set or transcode to ensure the accuracy of the query results. Whether it is setting the character set, converting the character set, using PDO to operate the database, or using the mysqli extension, we should pay more attention during the code writing process to ensure the correctness and safety of the program.

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