Can’t add new command when connection is in closed state

When you receive the error message “can’t add new command when connection is in closed state”, it means that the connection to the database or server has been closed, and you are trying to execute a new command on a closed connection. This can happen for various reasons, such as a timeout, manually closing the connection, or an error occurred during the connection process.

To resolve this issue, you need to ensure that the connection is open before executing any commands. Here is an example of how to properly handle connections with the MySQLi PHP extension:

        // Establish a connection
        $conn = new mysqli("localhost", "username", "password", "database");
        
        // Check if the connection was successful
        if ($conn->connect_errno) {
            die("Failed to connect to MySQL: " . $conn->connect_error);
        }
        
        // Execute commands on the open connection
        $result = $conn->query("SELECT * FROM table");
        
        // Check if the query was successful
        if (!$result) {
            die("Failed to execute query: " . $conn->error);
        }
        
        // Process the query result
        
        // Close the connection
        $conn->close();
    

In this example, we first establish a connection to the MySQL database using the mysqli class. We then check if the connection was successful using the “connect_errno” property. If the connection fails, we terminate the script and display an error message.

After ensuring the connection is open, we proceed to execute queries on the connection using the “query” method. If the query fails, we display an error message using the “error” property of the connection object.

Finally, we process the query result as needed, and then close the connection using the “close” method. It is important to always close the connection after you have finished using it to free up system resources and prevent memory leaks.