Question

我在aspnetusers表中又添加了2列，并添加了迁移。但是它失败并显示错误，表明FK_Projects_AspNetUsers_UserId'不是约束。无法删除约束。查看以前的错误。

public string NavbarBackGroundImagePath { get; set; }
public string NavbarBackGroundColorCode { get; set; }

添加了这两列。

migrationBuilder.DropForeignKey(
            name: "FK_Projects_AspNetUsers_UserId",
            table: "Projects");

        migrationBuilder.DropIndex(
            name: "IX_Projects_UserId",
            table: "Projects");

        migrationBuilder.DropColumn(
            name: "UserId",
            table: "Projects");

        migrationBuilder.AddColumn<int>(
            name: "WorkspaceId",
            table: "Projects",
            nullable: false,
            defaultValue: 0);

        migrationBuilder.AddColumn<string>(
            name: "NavbarBackGroundColorCode",
            table: "AspNetUsers",
            maxLength: 10,
            nullable: true);

        migrationBuilder.AddColumn<string>(
            name: "NavbarBackGroundImagePath",
            table: "AspNetUsers",
            maxLength: 200,
            nullable: true);

        migrationBuilder.CreateIndex(
            name: "IX_Projects_WorkspaceId",
            table: "Projects",
            column: "WorkspaceId");

        migrationBuilder.AddForeignKey(
            name: "FK_Projects_Workspaces_WorkspaceId",
            table: "Projects",
            column: "WorkspaceId",
            principalTable: "Workspaces",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

但是在迁移文件中，它占用了所有这些东西。

Answer 1

根据错误消息，如果Projects表不包含“ FK_Projects_AspNetUsers_UserId”约束或不包含“ UserId”，则当您要在Projects表中删除外键约束时，似乎发生此错误”属性，它将显示此错误。

因此，请检查数据库中的Projects表，是否已删除UerId列。以及Projects表是否具有AspNetUsers表的外键约束。如果Projects表不包含此约束，请尝试删除与DropForeignKey相关的代码：

   migrationBuilder.DropForeignKey(
        name: "FK_Projects_AspNetUsers_UserId",
        table: "Projects");

EF Core迁移将旧迁移与新列一起进行更改

1 个答案: