实体框架数据库迁移

Question

In my Application I have used Entity Framework Database First approach. Currently my application is in Dev Environment, now it need to be moved into Test Environment and later into Production Environment.

So is there anyway that I can use .net feature or Entity framework feature to migrate/create database in Test environment. Other than using SQL feature of restoring the database. Also note that if any enhancement comes then Database structure can change, table schema can change.

So can you suggest me the best way to easily migrate database schema in different environment without losing existing Data.

Answer 1

With Database First, the easiest way to copy a schema is to extract a data tier application in management studio, create an empty database on the target, register it as a data tier application with the same name, and upgrade the empty database using the upgraded file. You can repeat this step to manage schema changes.

Having said that, going forward you're really better off switching your Database First to Code First as it will make change management across your deployments much easier.

Answer 2

Migrations are best way to deal with it
Preferred way to update production db is to first generate sql file and then run the sql file in production environment.

MS had a very good artical on this

http://msdn.microsoft.com/en-in/data/jj591621.aspx#script

Answer 3

If you want to take advantage of EF-Migrations feature, you must convert your application to Code First with Existing Database http://msdn.microsoft.com/en-us/data/jj200620.aspx

If you are unable to convert to code first then you must create the update script by hand.

1. Use a schema compare tool , compare the development and production server.
2. For each difference found, create an update query.
3. Once the entire script is finished, test it on the staging server.

Automating the migration is very risky, it depends on the type and size changes you made to the schema. You can't trust any single feature or tool specially if the changes requires data motion (moving data around).

The following links might help you:

• How to do Migrations in DB first approach
• EF Migrations for Database-first approach?