You need to perform a one-time migration of data from a running Cloud SQL for...

Create and run a Dataflow job that uses JdbcIO to copy data from one Cloud SQL instance to another.

Create two Datastream connection profiles, and use them to create a stream from one Cloud SQL instance to another.

Create a SQL dump file in Cloud Storage using a temporary instance, and then use that file to import into a new instance.

Create a CSV file by running the SQL statement SELECT...INTO OUTFILE, copy the file to a Cloud Storage bucket, and import it into a new instance.