.Net Core3.1使用EFCore进行数据迁移（Migration）

开发环境

编译器：VS2019

运行环境

DotNet Core SDK(3.1.8) 

SqlServer迁移方式

依赖包

Microsoft.EntityFrameworkCore
Microsoft.EntityFrameworkCore.SqlServer

使用迁移命令需要的依赖包

Microsoft.EntityFrameworkCore.Tools
EntityFramework
Microsoft.EntityFrameworkCore.Design

迁移命令

1.创建第一个迁移 Add-Migration InitialCreate 2.创建数据库和架构 Update-Database 

如果在实体中需要新增CreatedTimestamp 字段

public class Blog { public int Id { get; set; } public string Name { get; set; } public DateTime CreatedTimestamp { get; set; } } 

执行如下命令创建新迁移：

Add-Migration AddBlogCreatedTimestamp

Update-Database

如果执行Update-Database异常需要删除上一个添加的迁移命令

删除上一个添加的迁移命令
Remove-Migration 

appsettings.json配置

新增ConnectionString节点

{
  "Logging": { "LogLevel": { "Default": "Information", "Microsoft": "Warning", "Microsoft.Hosting.Lifetime": "Information" } }, "AllowedHosts": "*", "ConnectionString": { "SqlServer": "server=.;database=NetCoreDemo;uid=sa;pwd=123" } } 

Startup.cs配置如下

public void ConfigureServices(IServiceCollection services) { string constr = Configuration.GetSection("ConnectionString:SqlServer").Value; services.AddDbContext<MyDbContext>(options => options.UseMySQL(connstr, m => m.MigrationsAssembly("User.API")); services.AddControllersWithViews(); } 

MySql迁移方式

依赖包

Microsoft.EntityFrameworkCore Microsoft.EntityFrameworkCore.Design Microsoft.EntityFrameworkCore.Tools MySql.Data.EntityFrameworkCore 

appsettings.json配置

新增ConnectionString节点

{
  "Logging": { "LogLevel": { "Default": "Information", "Microsoft": "Warning", "Microsoft.Hosting.Lifetime": "Information" } }, "AllowedHosts": "*", "ConnectionString": { "MySql": "Data Source=localhost;port=3306;database=NetCoreDemo;User Id=root;Password=12345" } } 

Startup.cs配置如下

public void ConfigureServices(IServiceCollection services) { var constr = Configuration.GetSection("ConnectionString:MySql").Value; services.AddDbContext<MyDbContext>( options.UseMySQL(connstr, m => m.MigrationsAssembly("User.API")); ); services.AddControllersWithViews(); } 

在依次执行上述迁移命令即可

注意执行命令时必须默认项目必须选择继承了DbContext 的那个程序集