In PHP, you can execute a query in a MySQL database using the mysqli_query function.

In PHP, you can use the mysqli_query function to execute a query in a MySQL database. This function takes two parameters: the connection object and the SQL query. It returns a result object that can be used to fetch data or perform other database operations. It's important to note that the mysqli_query function is part of the mysqli extension in PHP and should be used with prepared statements or proper escaping techniques to prevent SQL injection vulnerabilities.