The instance ID is the name of the instance. It is used to uniquely identify your instance within the project

Connect to your instance with instance ID myinstance:

gcloud sql connect myinstance --user=root

Create a SQL database called guestbook on your Cloud SQL instance:

CREATE DATABASE guestbook;

Insert the following sample data into the guestbook database:

USE guestbook;
CREATE TABLE entries (guestName VARCHAR(255), content VARCHAR(255),
    entryID INT NOT NULL AUTO_INCREMENT, PRIMARY KEY(entryID));
    INSERT INTO entries (guestName, content) values ("first guest", "I got here!");
INSERT INTO entries (guestName, content) values ("second guest", "Me too!");

Now retrieve the data:

SELECT * FROM entries;

Switch Database in a session: