Using PHP mysqli_query to Execute MySQL Queries

MySQL is a widely used relational database management system, and when developing web applications PHP provides several functions to connect to and operate MySQL databases. Among them, the mysqli_query function is a common way to execute query operations.

The mysqli_query function can run various types of MySQL statements, including SELECT, INSERT, UPDATE, DELETE, etc. It accepts two parameters: the database connection object and the SQL query string. Below is a complete example that demonstrates a SELECT query.

';
}

// Free result set
mysqli_free_result($result);

// Close connection
mysqli_close($connection);
?>

The code first creates a database connection and verifies it, then uses mysqli_query to run a SELECT statement and stores the result in the $result variable. It iterates over $result with mysqli_fetch_assoc to print each row's ID, name, and age, and finally frees the result set and closes the connection.

Beyond SELECT, mysqli_query can execute other statements such as INSERT to add data, UPDATE to modify data, and DELETE to remove data; you simply pass the appropriate SQL as the second argument.

When mysqli_query runs a SELECT statement, it returns a result set object. You can retrieve rows from this object using functions like mysqli_fetch_assoc , mysqli_fetch_row , or mysqli_fetch_array , depending on the desired format.

In summary, using PHP's mysqli_query function provides a convenient and efficient way to perform MySQL operations such as SELECT, INSERT, UPDATE, and DELETE within web applications.