EF Core Database Migration (migration)

Introduction to Tools and environment

1. Development environment vs 2015

The 2.mysql EF Core supports the POMELO.ENTITYFRAMEWORKCORE.MYSQL source code address (https://github.com/PomeloFoundation/ POMELO.ENTITYFRAMEWORKCORE.MYSQL)

Scene

Design two tables user and posting table (user)

One user corresponds to multiple users

Coding Begin1. Create a new project (Create a new empty console project)

2. Add Nuget.config

Add two feeds, one is pomelo (MySQL EF core support), and the other is NuGet

The code is as follows:

<?xml version="1.0" encoding="utf-8"?>< configuration>  <packageSources>    <add key="pomelo" value="  Https://www.myget.org/F/pomelo/api/v3/index.json" />    <add key="  nuget.org "value="https://www.nuget.org/api/v2 "/ >  </packageSources></configuration>

3. Increase EF core dependency in Project.json while adding EF Tool (for database migrations)

{  "version":"1.0.0-*",  "buildoptions": {    "Emitentrypoint":true  },  "Dependencies": {    "Microsoft.NETCore.App": {      "type":"Platform",      "version":"1.0.0"    },    "POMELO.ENTITYFRAMEWORKCORE.MYSQL":"1.0.0",    "Microsoft.EntityFrameworkCore.Tools":"1.0.0-preview2-final"  },  "Tools": {    "Microsoft.EntityFrameworkCore.Tools":"1.0.0-preview2-final"  },  "Frameworks": {    "netcoreapp1.0": {      "Imports":"Dnxcore50"    }  }}

4. Add User,post entity and DB database context files

The code is as follows:

 Public classUser { Public intId {Set;Get; }  Public stringUserName {Set;Get; }  Public stringPassword {Set;Get; } } Public classpost{ Public intId {Set;Get; }  Public stringTitle {Set;Get; }  Public stringDescription {Set;Get; }  PublicDateTime CreatedDate {Set;Get; }  Public intUserId {Set;Get; }}  Public classDb:dbcontext { PublicDbset<user> Users {Set;Get; }  PublicDbset<post> Posts {Set;Get; } protected Override voidonmodelcreating (ModelBuilder ModelBuilder) {Base.        Onmodelcreating (ModelBuilder); }        protected Override voidonconfiguring (Dbcontextoptionsbuilder optionsbuilder)=Optionsbuilder. Usemysql (@"server=localhost;database=migrationtest;uid=root;pwd=password12!;");} 

5. Generating a database from migration

Enter the following two commands in the Package Manager console in VS
Add-migration Init (execute this command project to generate a directory (migration))
Update-database Init

Before executing

Execute add-migration init (Generate Migration folder)

Execute update-database Init

After the command is executed, the database generates

Post table

6. Inserting data into the database

7. Modify the Entity field, add a field to the post entity, and modify the name of a field

Post-modification posts are as follows

 Public classpost{ Public intId {Set;Get; }  Public stringTitle {Set;Get; }  Public stringHint {Set;Get; }  PublicDateTime CreatedDate {Set;Get; }  Public intUserId {Set;Get; }  Public stringRemark {Set;Get; } }

8. Execute the Migration command

Add-migration UpdateDB
Update-database UpdateDB

Post table after performing the migration

EF Core Database Migration (migration)