Why PHP can't read Chinese characters in MySQL

Whether it is developing programs or websites, PHP and MySQL are often used together. However, you may encounter some problems if your MySQL database contains Chinese characters. Specifically, PHP cannot read Chinese characters in MySQL. This is a common problem between PHP and MySQL.

Why can’t PHP read Chinese characters in MySQL?

To understand this problem, you must have a deep understanding of encoding and character sets. Encoding is the process of converting characters into numbers that computers can understand and store. A character set is a set of rules that defines character encoding. The Chinese character set is a multi-byte character set in which a Chinese character may require two or more bytes to represent.

Since PHP and MySQL are two different systems, they may use different character encodings and character sets. If the two use different encodings, it may cause failure to read Chinese characters in MySQL. Because MySQL uses the Latin-1 character set by default, and most Chinese characters cannot be represented by the Latin-1 character set, PHP cannot read Chinese characters in MySQL by default.

how to solve this problem?

First of all, you can find a solution by checking the character set settings in MySQL and the character set settings of PHP.

1. Modify the MySQL database character set

To make MySQL support Chinese characters, you can change its character set to the utf8mb4 character set. This can be done with the following command:

ALTER DATABASE database_name CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci;

This command changes the database to use the utf8mb4 character set and utf8mb4_unicode_ci collation. In this way, MySQL can correctly store, display, and read Chinese characters.

2. Modify PHP’s character set

By default, PHP uses the Latin-1 character set. Therefore, to enable PHP to handle Chinese characters correctly, you need to add the following code to the PHP file to change the character set, for example:

header('Content-Type: text/html; charset=utf- 8');

This code will set the character set to utf-8 so that PHP can read and process Chinese characters correctly.

3. Set the character set when connecting to MySQL

Another method is to set the character set to utf8mb4 when connecting to MySQL. You can use the following code to achieve this:

$mysqli = new mysqli("localhost", "user", "password", "database");
if ($mysqli->connect_errno) {
    echo "Failed to connect to MySQL: " . $mysqli->connect_error;
    exit();
}

if (!$mysqli->set_charset("utf8mb4")) {
    printf("Error loading character set utf8mb4: %s\n", $mysqli->error);
    exit();
}

With this method, you can set the character set to utf8mb4 when connecting to the MySQL database to ensure that PHP can read and process Chinese characters correctly.

Summary

When using PHP and MySQL, it is very important to correctly handle Chinese characters. Since the two may use different character encodings and character sets, reading Chinese characters in MySQL may fail. By modifying the MySQL database character set, modifying PHP's character set, or setting the character set when connecting to MySQL, you can solve this problem and enable PHP to read and process Chinese characters correctly.

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