Can I use a MySQL database with an App Engine application

Question

I know that App Engine has its own datastore. This is great for most cases and fairly easy to used. However, we have a MySQL database that we use for several applications an

Answer 1

Yes, you can.

Read about int https://cloud.google.com/sql/docs

You can use it with any language supported by GAE and connect over it from outside GAE too.

Answer 2

Using a Local MySQL Instance During Development:

 


 import com.google.appengine.api.rdbms.AppEngineDriver;
    public static void makeConnection() {
        try {
            if (conn == null || !conn.isValid(0)) {
                String url = "localhost/databasename";
                String username = "root";
                String password = "password";
                DriverManager.registerDriver(new AppEngineDriver());
                String urlForConnection = "jdbc:mysql://" + url;
                conn = DriverManager.getConnection(urlForConnection, username, password);
            }
        } catch (SQLException e) {
            e.printStackTrace();
        }
    }

// in web.xml
    <filter>
        <filter-name>_ah_DevSocketFilter</filter-name>
        <filter-class>com.google.appengine.api.socket.dev.DevSocketFilter</filter-class>
        <init-param>
            <param-name>use-native-sockets</param-name>
            <param-value>true</param-value>
        </init-param>
    </filter>

    <filter-mapping>
        <filter-name>_ah_DevSocketFilter</filter-name>
        <url-pattern>/*</url-pattern>
    </filter-mapping>

Using cloud

 

    DriverManager.registerDriver(new AppEngineDriver());
              c = DriverManager.getConnection("jdbc:google:rdbms://instance_name/guestbook");