How to handle MySQL query errors in PHP?

Handling MySQL query errors in PHP is very important. There are several ways to do this, including using the mysqli_error() and mysqli_errno() functions to get the error message and code, and using exceptions. Enabling error reporting, logging errors, and using prepared statements are also helpful suggestions.

Handling MySQL query errors in PHP

When using PHP to process MySQL queries, you may encounter errors. Handling these errors is critical to ensuring your application is robust and stable.

Error handling methods

PHP provides a variety of methods to handle MySQL errors:

1. mysqli_error():Get the error message of the latest query.
2. mysqli_errno(): Get the error code of the latest query.
3. mysqli_error_list(): Get all known MySQL error codes and their descriptions.
4. Exception: Exceptions can be caught using the mysqli_* function.

Practical case

The following is an example of using the mysqli_error() and mysqli_errno() functions to handle errors Example:

<?php

// 连接数据库
$conn = new mysqli("localhost", "root", "password", "my_database");

// 设置错误处理
$conn->setAttribute(MYSQLI_ATTR_ERRNO_REPORT, true);
$conn->setAttribute(MYSQLI_ATTR_CONNECTION_ERROR, true);

// 执行查询
$result = $conn->query("SELECT * FROM users");

if (!$result) {
    echo "查询错误： " . $conn->error . " (" . $conn->errno . ")";
} else {
    // 处理查询结果
}

?>

Other suggestions

• Enable error reporting: You can enable it using the ini_set() function PHP error reporting. This will help with debugging and finding errors.
• Using Exceptions: Handling MySQL errors using exceptions is more convenient because they provide more information about the error.
• Logging Errors: Logging error information can help you troubleshoot and track issues.
• Use prepared statements: Prepared statements can prevent SQL injection attacks and simplify error handling.

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