Migration Anatomy of EF Code First Database migration

1. Introduction

The Entity Framework's code First approach provides a way to write model models, generate model changes, and modify databases based on model changes.

And since its environment is a strong nuget, if it is VS2010 a classmate, please do not look down, there will be no benefit.

2. Operation Step 1) Establish or modify model, i.e. entity class;

Here is a demonstration of the modification:

 Public classbootstraplists { Public intID {Get;Set; }  Public stringTitle {Get;Set; } [DataType (Datatype.multilinetext)] Public stringDescription {Get;Set; } /// <summary>        ///Add a Time field/// </summary>         PublicDateTime CreateDate {Get;Set; } }

2) Establish or modify modelmap;

 Public classBootstraplistsmap:entitytypeconfiguration<bootstraplists>{     PublicBootstraplistsmap () {ToTable (""); Haskey (ZW= Zw.id). Property (ZW = Zw.id). Hascolumnname ("ID"); Property (ZW= ZW. Title). Hascolumnname ("Title"); Property (ZW= ZW. Description). Hascolumnname ("Description"); //NewProperty (ZW = ZW). CreateDate). Hascolumnname ("CreateDate"); }}

3) Add map to Onmodelcreate;

 Public Get Set ; }         protected Override void onmodelcreating (Dbmodelbuilder modelBuilder)        {            modelBuilder.Configurations.Add (new  bootstraplistsmap ());             // dynamically load all configuration

4) using the command add-migration

If you are using it for the first time, first use:

Enable-migrations

The files and folders shown in the red box are generated

To continue using the command:

Add-migration Tests

Where tests is the custom name;

To generate a migration file:

5) using the command update-database

Update-database

Migration Principle : Query the database table, __migrationhistory, traverse all files under the Migrations folder, if the file is not in the __migrationhistory table, then perform the migration.

Eg: If 20141104233562_tests is not in the database, the migration is performed.

11) Initial Database:

22) Execution:

33) After executing the database:

To modify the results of a table:

6) Dig deep

 public  partial  class   tests:dbmigration{ public  override  void   up () {ADD Column (  " dbo. bootstraplists   ", "  createdate  " , C = C.datetime (nullable: true   public  override  void   down () {}}  

Class, Dbmigration mail a lot of API, you can directly modify the database!

Migration Anatomy of EF Code First Database migration