How to add column in table in existing application in react native?

Question

I am using "react-native-sqlite-storage", for local database in react native, the application is already live on play store. But now I want to alter the table and add two new columns in the existing database table in such a way that the application will not crash for existing user.

Please help me.

Answer 1

When you will add column to existing table you will get error like

error: {"message":"no such column: todoStar","code":5} // todoStar is column name

In error block you can alter the table and add your column. Make sure you write the code inside error block

  if (error.message.indexOf('no such column: todoStar') > -1) {
          dbConnection.transaction(function (tx2) {
            let query = 'ALTER TABLE todos ADD todoStar Int(32);'; // todos is tableName
            tx2.executeSql(
              query,
              '',
              async (tx3) => {
                console.log('new column added');
              },
              (error) => {
                console.error(
                  'error: while adding column' + JSON.stringify(error),
                );
              },
            );
          });
        }

Answer 2

If I understand you correctly, you want to receive a notification to your server whenever a calendar event changes.

If that's the case, consider using push notifications:

• First, set up a URL where notifications will be received.
• Second, call Events: watch to set up the notification channel.

Take a look at push notifications for a complete guide on this, and Events: watch for documentation on the method you'll have to call after setting up the webhook.