Using PHP mysqli_query to Execute MySQL Queries

MySQL is a widely used relational database management system, and when developing web applications it is common to execute various queries. PHP, a popular server‑side language, offers many functions for connecting to and operating MySQL databases, among which the mysqli_query function is frequently used to run queries.

The mysqli_query function can execute all types of MySQL statements, including SELECT, INSERT, UPDATE, and DELETE. It takes two arguments: the database connection object and the SQL query string. The following example demonstrates using mysqli_query to perform a SELECT query.

';
}

// 释放结果集
mysqli_free_result($result);

// 关闭数据库连接
mysqli_close($connection);
?>

The script first creates a database connection and verifies its success. It then runs a SELECT statement with mysqli_query , storing the result in the $result variable. By looping over $result with mysqli_fetch_assoc , each row’s ID, name, and age are printed. Finally, the result set is freed and the connection closed.

Beyond SELECT, mysqli_query can execute other statements such as INSERT, UPDATE, and DELETE by passing the appropriate SQL as the second argument.

Note that mysqli_query returns a result‑set object for queries that produce results. You can retrieve rows using functions like mysqli_fetch_assoc , mysqli_fetch_row , or mysqli_fetch_array , depending on the desired format.

In summary, the PHP mysqli_query function provides a convenient way to interact with MySQL databases for a variety of operations, making it easy to perform SELECT, INSERT, UPDATE, and DELETE tasks.