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c# - 在模型 .net Core 2.2 中将数据类型从 int 更改为 long 的关键属性

问题描述

我想将 ASP.Net core 2.2 中模型主键的数据类型从 int 更改为 long，因为它即将超出 int 范围。该应用程序是代码优先完成的，并使用 SQL 服务器作为数据库。

更改模型中的数据类型并运行 Add-Migration 也可以，但 Update-Database 失败并出现错误：

System.Data.SqlClient.SqlException (0x80131904): The index 'IX_tblMTransactions_OriginalTransactionId' is dependent on column 'OriginalTransactionId'.
The object 'FK_tblMTransactions_tblMTransactions_OriginalTransactionId' is dependent on column 'OriginalTransactionId'.

所以我读到了它，似乎需要对迁移进行一些调整，比如在列更改之前删除外键和索引，然后再将它们带回来。不幸的是，我在 .net core 2.2 中找不到任何有用的信息，我找到的最接近的是这个问题，但它谈到了 .net core 2.1 和选项DropForeignKey，并DropIndex 提到那里似乎不再可用.net core 2.2 根据这篇文章。

这是迁移类：

public partial class _20190817_1746 : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.AlterColumn<long>(
            name: "OriginalTransactionId",
            table: "tblMTransactions",
            nullable: true,
            oldClrType: typeof(int),
            oldNullable: true);

        migrationBuilder.AlterColumn<long>(
            name: "Id",
            table: "tblMTransactions",
            nullable: false,
            oldClrType: typeof(int))
            .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn)
            .OldAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.AlterColumn<int>(
            name: "OriginalTransactionId",
            table: "tblMTransactions",
            nullable: true,
            oldClrType: typeof(long),
            oldNullable: true);

        migrationBuilder.AlterColumn<int>(
            name: "Id",
            table: "tblMTransactions",
            nullable: false,
            oldClrType: typeof(long))
            .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn)
            .OldAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
    }
}

这是该表的列、键和索引的屏幕截图： 桌子

有人知道如何调整 .NET Core 2.2 中的迁移类以使其正常工作吗？

谢谢

标签： c#asp.net-core-mvcentity-framework-core-2.2

解决方案

感谢Ivan Stoev，我能够找到解决方案。我必须像这样手动添加索引和键的删除和创建：

public partial class _20190817_2317 : Migration
{
    protected override void Up(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.DropForeignKey(
            name: "FK_tblMTransactions_tblMTransactions_OriginalTransactionId",
            table: "tblMTransactions");

        migrationBuilder.DropIndex(
            name: "IX_tblMTransactions_OriginalTransactionId",
            table: "tblMTransactions");

        migrationBuilder.DropPrimaryKey(
            name: "PK_tblMTransactions",
            table: "tblMTransactions");

        migrationBuilder.AlterColumn<long>(
            name: "OriginalTransactionId",
            table: "tblMTransactions",
            nullable: true,
            oldClrType: typeof(int),
            oldNullable: true);

        migrationBuilder.AlterColumn<long>(
            name: "Id",
            table: "tblMTransactions",
            nullable: false,
            oldClrType: typeof(int))
            .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn)
            .OldAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);

        migrationBuilder.AddPrimaryKey(
            name: "PK_tblMTransactions",
            table: "tblMTransactions",
            column: "Id");

        migrationBuilder.CreateIndex(
            name: "IX_tblMTransactions_OriginalTransactionId",
            table: "tblMTransactions",
            column: "OriginalTransactionId");

        migrationBuilder.AddForeignKey(
            name: "FK_tblMTransactions_tblMTransactions_OriginalTransactionId",
            table: "tblMTransactions",
            column: "OriginalTransactionId",
            principalTable: "tblMTransactions",
            principalColumn: "Id",
            onDelete: ReferentialAction.Restrict);
    }

    protected override void Down(MigrationBuilder migrationBuilder)
    {
        migrationBuilder.AlterColumn<int>(
            name: "OriginalTransactionId",
            table: "tblMTransactions",
            nullable: true,
            oldClrType: typeof(long),
            oldNullable: true);

        migrationBuilder.AlterColumn<int>(
            name: "Id",
            table: "tblMTransactions",
            nullable: false,
            oldClrType: typeof(long))
            .Annotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn)
            .OldAnnotation("SqlServer:ValueGenerationStrategy", SqlServerValueGenerationStrategy.IdentityColumn);
    }
}

再次感谢，伊万！

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