如何使用适用于当前数据库的DbContext
(现在用于迁移)。
示例:
namespace Data.SqlServer.Migrations
{
[DbContext(typeof(MyDbContext))] // I want use this context
[Migration("CustomMigration_DataSeed")]
public partial class DataSeedMigration : Migration
{
protected override void Up(MigrationBuilder migrationBuilder)
{
// add some entities
_context.User.Add(new User());
}
protected override void Down(MigrationBuilder migrationBuilder)
{
}
}
}
感谢您的帮助!
答案 0 :(得分:2)
为迁移配置创建一个类:
internal sealed class Configuration : DbMigrationsConfiguration<MyDbContext>
{
public Configuration()
{
AutomaticMigrationsEnabled = true;
//On true you might be losing data be aware.
AutomaticMigrationDataLossAllowed = false;
ContextKey = "Path To Your DbContext";
}
protected override void Seed(MyDbContext context)
{
// This method will be called after migrating to the latest version.
// You can use the DbSet<T>.AddOrUpdate() helper extension method
// to avoid creating duplicate seed data. E.g.
//
// context.People.AddOrUpdate(
// p => p.FullName,
// new Person { FullName = "Andrew Peters" },
// new Person { FullName = "Brice Lambson" },
// new Person { FullName = "Rowan Miller" }
// );
//
}
}
然后将此引用到您的DbContext类:
public class MyDbContext : DbContext
{
public MyDbContext()
: base("name=MyConnection")
{
Database.SetInitializer(new MigrateDatabaseToLatestVersion<MyDbContext,Configuration>("MyConnection"));
}
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
//here you can MAP Your Models/Entities
}
}
请记住,如果您不想迁移多个POCO,请不要在OnModelCreating方法中添加它们并对其进行评论。