Close connection

When we are finished querying the database, it is recommended to close the connection to free up resources.

Object oriented style

$conn->close();

Procedural style

mysqli_close($conn);

Note: The connection to the server will be closed as soon as the execution of the script ends, unless it’s closed earlier by explicitly calling the close connection function.

Use Case: If our script has a fair amount of processing to perform after fetching the result and has retrieved the full result set, we definitely should close the connection. If we were not to, there’s a chance the MySQL server will reach its connection limit when the web server is under heavy use.