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How DB migration is done?
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.
When should you run DB 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.
What is a migration script?
Migration scripts are customizable SQL scripts created by user through ApexSQL Source Control containing any specific configuration changes, or overrides that need to be executed before or after applying an object change from source control, or they can be executed instead of a change.
How can we use database migration during development?
The following steps show how we can use database migration during development: Tim creates a new migration (e.g. create a new table) Tim commits the new migration into source control system (e.g. SVN, GIT) Yii supports database migration via the yiic migrate command line tool.
How does database migration work in PHP framework?
If you confirm to apply the migrations, it will run the up () method in every new migration class, one after another, in the order of the timestamp value in the class name. After applying a migration, the migration tool will keep a record in a database table named tbl_migration.
How to change the number of migrations in PHP?
Changing the value 3 will allow us to change the number of migrations to be applied. We can also migrate the database to a specific version with the following command: That is, we use the timestamp part of a migration name to specify the version that we want to migrate the database to.
How to do migrations in a branching system?
We just have a pile of SQL and XML scripts that we apply to the baseline to get a current system (migrations, essentially, but not designed to be run incrementally). Updating or switching branches is then very simple: nuke the database, load a dump to establish the baseline, run the scripts.