Using PHP mysqli_query to Execute MySQL Queries

MySQL is a widely used relational database management system, and when developing web applications developers often need to perform various queries. PHP, a common server‑side language, provides functions to connect to and operate MySQL databases, with mysqli_query being a primary function for executing queries.

The mysqli_query function can execute many types of MySQL statements, including SELECT, INSERT, UPDATE, and DELETE. It accepts two parameters: the database connection object and the SQL query string. Below is an example that performs a SELECT query.

';
}

// 释放结果集
mysqli_free_result($result);

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

The example code first creates a database connection and checks its success, then runs a SELECT query and stores the result in $result . It iterates over $result to output each row’s ID, name, and age, finally freeing the result set and closing the connection.

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

It is important to note that mysqli_query returns a result set object for SELECT queries; you can retrieve rows using functions like mysqli_fetch_assoc , mysqli_fetch_row , or mysqli_fetch_array to obtain different result formats.

In summary, using PHP’s mysqli_query function provides a convenient and efficient way to perform common database operations, making it a valuable tool for backend developers working with MySQL.