What is the purpose of database migrations?
Database migration is the process of migrating data from one or more source databases to one or more destination databases using a database migration service. When a migration completes, the data set from the source databases resides entirely, though possibly restructured, in the target databases.
Table of Contents
When should you run database migrations?
Run the database migrations first, before deploying the new code. This means that the code above should work with both database schemas, but the code below can assume that the tables have already been added.
Should I use database migrations?
Migrations are useful because they allow database schemas to evolve as requirements change. They help developers safely plan, validate, and apply schema changes to their environments. The database schema and the application’s assumptions about that structure can evolve in tandem.
How do you handle database migrations?
Database migrations done right
- schema change to add a nullable column.
- update the software to write to the nullable column and handle nulls on read.
- perform the data migration to update the null columns to have the correct data.
- run a schema change to set the column to non-nullable.
Why do you need EF Core database migration?
What is EF Core Database Migration? Suppose you submitted an application that creates a database that contains a table with two columns. As you develop the next version, you realize that you will need to modify the database structure to add the wonderful features you are working on.
What do you need to know about database migration?
That’s where database migration comes into play. The migration consists of modifying the database from version x to version and maintaining the previous data as much as possible. Common tasks performed in a migration process are: add or remove a column, add or remove a table, etc.
How to add migration to DotNet EF migrations?
dotnet ef migrations add InitialMigration (create first migration) After running these commands, the database becomes aware of the migration and can handle future updates to its structure. The last step here is to tell EF Core in the code to create the database with the migration in mind.
What is the best database migration tool for Java?
Join the hundreds of thousands of delighted users. Database migrations are something Java developers struggle with, and Flyway provides a nice tool that anyone with basic SQL knowledge can use. That’s why it has become the Spring Boot team’s favorite migration tool.