How do you handle database migrations?

Database migrations done right

1. schema change to add a nullable column.
2. update the software to write to the nullable column and handle nulls on read.
3. perform data migration to update the null columns to have the correct data.
4. execute a schema change to set the column to not-nullable.

When should you run database migrations?

Run the database migrations first, before you deploy the new code. This means the before code must work with both database schemas, but the after code can assume that the tables have already been added.

Why do we need database migration?

Database migration is important because it helps to save money. The benefit of database migration is that it helps move data from an outdated legacy system to a modernized software. Database migration helps to unify disparate data so that it is accessible by different systems.

Can the database be migrated if yes explain the process?

The process of database migration can involve multiple phases and iterations — including assessing the current databases and future needs of the company, migrating the schema, and normalizing and moving the data. Plus, testing, testing, and more testing.

How do you transfer data between databases?

1. Right click on the database you want to copy.
2. ‘Tasks’ > ‘Export Data’
3. Next, Next.
4. Choose the database to copy the tables to.
5. Mark ‘Copy data from one or more tables or views’
6. Choose the tables you want to copy.
7. Finish.

How do you migrate a database?

In order to migrate the database, there are two steps:

1. Step One—Perform a MySQL Dump. Before transferring the database file to the new VPS, we first need to back it up on the original virtual server by using the mysqldump command.
2. Step Two—Copy the Database. SCP helps you copy the database.
3. Step Three—Import the Database.

What are database migration scripts?

What is a Migration Script? Whereas a build script creates a database, a migration script, or ‘change’ script, alters a database. It is called a migration script because it changes all or part of a database from one version to another. It ‘migrates’ it between versions.