实体框架迁移重命名表和列

没关系，我把事情搞得太复杂了。

这就是我所需要的。重命名方法只生成对 Sp _ rename系统存储过程的调用，我猜这样就可以解决所有问题，包括具有新列名的外键。

public override void Up()
{
RenameTable("ReportSections", "ReportPages");
RenameTable("ReportSectionGroups", "ReportSections");
RenameColumn("ReportPages", "Group_Id", "Section_Id");
}


public override void Down()
{
RenameColumn("ReportPages", "Section_Id", "Group_Id");
RenameTable("ReportSections", "ReportSectionGroups");
RenameTable("ReportPages", "ReportSections");
}

我刚刚在 EF6(代码第一实体重命名)中尝试了同样的方法。我只是重命名了这个类，并使用包管理器控制台添加了一个迁移，瞧，使用 RenameTable (...)的迁移就自动为我生成了。我必须承认，我确定对实体的唯一改变是重命名，所以没有新的列或重命名的列，所以我不能确定这是一个 EF6的东西或只是 EF (总是)能够检测到这样简单的迁移。

如果你不喜欢手工编写/修改需要的迁移类代码，你可以采用两步法自动生成所需的 RenameColumn代码:

第一步 使用 ColumnAttribute引入新的列名，然后添加-迁移(例如 Add-Migration ColumnChanged)

public class ReportPages
{
[Column("Section_Id")]                 //Section_Id
public int Group_Id{get;set}
}

步骤-第二步 更改属性名，并再次应用于 Package Manager Console 中的相同迁移(例如 Add-Migration ColumnChanged -force)

public class ReportPages
{
[Column("Section_Id")]                 //Section_Id
public int Section_Id{get;set}
}

如果你看一下迁移类，你可以看到自动生成的代码是 RenameColumn。

为了扩展 Hossein Narimani Rad 的答案，您可以使用 System 重命名表和列。组件模型。数据注释。图式。属性和系统。组件模型。数据注释。图式。分别为 ColumnAttribute。

这有几个好处:

1. 这不仅会自动创建名称迁移，而且
2. 它还将删除所有外键，并根据新的表和列名重新创建它们，从而为外键和包含赋予恰当的名称。
3. 所有这些都不会丢失任何表数据

例如，添加 [Table("Staffs")]:

[Table("Staffs")]
public class AccountUser
{
public long Id { get; set; }


public long AccountId { get; set; }


public string ApplicationUserId { get; set; }


public virtual Account Account { get; set; }


public virtual ApplicationUser User { get; set; }
}

将产生迁移:

    protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.DropForeignKey(
name: "FK_AccountUsers_Accounts_AccountId",
table: "AccountUsers");


migrationBuilder.DropForeignKey(
name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
table: "AccountUsers");


migrationBuilder.DropPrimaryKey(
name: "PK_AccountUsers",
table: "AccountUsers");


migrationBuilder.RenameTable(
name: "AccountUsers",
newName: "Staffs");


migrationBuilder.RenameIndex(
name: "IX_AccountUsers_ApplicationUserId",
table: "Staffs",
newName: "IX_Staffs_ApplicationUserId");


migrationBuilder.RenameIndex(
name: "IX_AccountUsers_AccountId",
table: "Staffs",
newName: "IX_Staffs_AccountId");


migrationBuilder.AddPrimaryKey(
name: "PK_Staffs",
table: "Staffs",
column: "Id");


migrationBuilder.AddForeignKey(
name: "FK_Staffs_Accounts_AccountId",
table: "Staffs",
column: "AccountId",
principalTable: "Accounts",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);


migrationBuilder.AddForeignKey(
name: "FK_Staffs_AspNetUsers_ApplicationUserId",
table: "Staffs",
column: "ApplicationUserId",
principalTable: "AspNetUsers",
principalColumn: "Id",
onDelete: ReferentialAction.Restrict);
}


protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.DropForeignKey(
name: "FK_Staffs_Accounts_AccountId",
table: "Staffs");


migrationBuilder.DropForeignKey(
name: "FK_Staffs_AspNetUsers_ApplicationUserId",
table: "Staffs");


migrationBuilder.DropPrimaryKey(
name: "PK_Staffs",
table: "Staffs");


migrationBuilder.RenameTable(
name: "Staffs",
newName: "AccountUsers");


migrationBuilder.RenameIndex(
name: "IX_Staffs_ApplicationUserId",
table: "AccountUsers",
newName: "IX_AccountUsers_ApplicationUserId");


migrationBuilder.RenameIndex(
name: "IX_Staffs_AccountId",
table: "AccountUsers",
newName: "IX_AccountUsers_AccountId");


migrationBuilder.AddPrimaryKey(
name: "PK_AccountUsers",
table: "AccountUsers",
column: "Id");


migrationBuilder.AddForeignKey(
name: "FK_AccountUsers_Accounts_AccountId",
table: "AccountUsers",
column: "AccountId",
principalTable: "Accounts",
principalColumn: "Id",
onDelete: ReferentialAction.Cascade);


migrationBuilder.AddForeignKey(
name: "FK_AccountUsers_AspNetUsers_ApplicationUserId",
table: "AccountUsers",
column: "ApplicationUserId",
principalTable: "AspNetUsers",
principalColumn: "Id",
onDelete: ReferentialAction.Restrict);
}

表名和列名可以作为 DbContext映射的一部分指定。那么在迁移中就没有必要这样做了。

public class MyContext : DbContext
{
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Restaurant>()
.HasMany(p => p.Cuisines)
.WithMany(r => r.Restaurants)
.Map(mc =>
{
mc.MapLeftKey("RestaurantId");
mc.MapRightKey("CuisineId");
mc.ToTable("RestaurantCuisines");
});
}
}

在 EF Core 中，我使用以下语句来重命名表和列:

至于表的重命名:

    protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameTable(
name: "OldTableName",
schema: "dbo",
newName: "NewTableName",
newSchema: "dbo");
}


protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameTable(
name: "NewTableName",
schema: "dbo",
newName: "OldTableName",
newSchema: "dbo");
}

至于重命名列:

    protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameColumn(
name: "OldColumnName",
table: "TableName",
newName: "NewColumnName",
schema: "dbo");
}


protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameColumn(
name: "NewColumnName",
table: "TableName",
newName: "OldColumnName",
schema: "dbo");
}

在 efcore 中，您可以更改在添加迁移之后创建的迁移。然后更新数据库。以下是一个样本:

protected override void Up(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameColumn(name: "Type", table: "Users", newName: "Discriminator", schema: "dbo");
}


protected override void Down(MigrationBuilder migrationBuilder)
{
migrationBuilder.RenameColumn(name: "Discriminator", table: "Users", newName: "Type", schema: "dbo");
}

对于 EFCoremigrationBuilder.RenameColumn通常工作良好，但有时你必须处理索引以及。

migrationBuilder.RenameColumn(name: "Identifier", table: "Questions", newName: "ChangedIdentifier", schema: "dbo");

更新数据库时的错误消息示例:

Microsoft.Data.SqlClient.SqlException (0x80131904) : 索引 ‘ IX _ questions _ Identifier’取决于列‘ Identifier’。

索引‘ IX _ questions _ Identifier’依赖于列‘ Identifier’。

RENAME 列标识符失败，因为一个或多个对象访问 本专栏。

在这种情况下，您必须这样重命名:

migrationBuilder.DropIndex(
name: "IX_Questions_Identifier",
table: "Questions");


migrationBuilder.RenameColumn(name: "Identifier", table: "Questions", newName: "ChangedIdentifier", schema: "dbo");


migrationBuilder.CreateIndex(
name: "IX_Questions_ChangedIdentifier",
table: "Questions",
column: "ChangedIdentifier",
unique: true,
filter: "[ChangedIdentifier] IS NOT NULL");

侯赛因 · 纳里马尼 · 拉德(Hossein Narimani Rad)的回答非常好，也非常直截了当。但它不适用于 EF 核心。因为 dotnet ef migration add没有 --force选项。