c# - SQLite 不支持此迁移操作 ('AlterColumnOperation')

Question

这是我的 DbContext：

using DatingApp.API.Models;
using Microsoft.EntityFrameworkCore;

namespace DatingApp.API.Data
{
    public class DataContext : DbContext
    {
        public DataContext(DbContextOptions<DataContext> options) : base(options){ }

        public DbSet<Value> Values { get; set; }
        public DbSet<User> User { get; set; }
        public DbSet<Photo> Photos { get; set; }
    }
}

这是我生成的文件迁移：

using System;
using Microsoft.EntityFrameworkCore.Migrations;

namespace DatingApp.API.Migrations
{
    public partial class ExtendedUserClass : Migration
    {
        protected override void Up(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.AlterColumn<string>(
                name: "Username",
                table: "User",
                nullable: true,
                oldClrType: typeof(int));

            migrationBuilder.AddColumn<string>(
                name: "City",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<string>(
                name: "Country",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<DateTime>(
                name: "Created",
                table: "User",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));

            migrationBuilder.AddColumn<DateTime>(
                name: "DateOfBirth",
                table: "User",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));

            migrationBuilder.AddColumn<string>(
                name: "Gender",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<string>(
                name: "Interests",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<string>(
                name: "Introduction",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<string>(
                name: "KnownAs",
                table: "User",
                nullable: true);

            migrationBuilder.AddColumn<DateTime>(
                name: "LastActive",
                table: "User",
                nullable: false,
                defaultValue: new DateTime(1, 1, 1, 0, 0, 0, 0, DateTimeKind.Unspecified));

            migrationBuilder.AddColumn<string>(
                name: "LookingFor",
                table: "User",
                nullable: true);

            migrationBuilder.CreateTable(
                name: "Photos",
                columns: table => new
                {
                    Id = table.Column<int>(nullable: false)
                        .Annotation("Sqlite:Autoincrement", true),
                    Url = table.Column<string>(nullable: true),
                    Description = table.Column<string>(nullable: true),
                    DateAdded = table.Column<DateTime>(nullable: false),
                    IsMain = table.Column<bool>(nullable: false),
                    UserId = table.Column<int>(nullable: false)
                },
                constraints: table =>
                {
                    table.PrimaryKey("PK_Photos", x => x.Id);
                    table.ForeignKey(
                        name: "FK_Photos_User_UserId",
                        column: x => x.UserId,
                        principalTable: "User",
                        principalColumn: "Id",
                        onDelete: ReferentialAction.Cascade);
                });

            migrationBuilder.CreateIndex(
                name: "IX_Photos_UserId",
                table: "Photos",
                column: "UserId");
        }

        protected override void Down(MigrationBuilder migrationBuilder)
        {
            migrationBuilder.DropTable(
                name: "Photos");

            migrationBuilder.DropColumn(
                name: "City",
                table: "User");

            migrationBuilder.DropColumn(
                name: "Country",
                table: "User");

            migrationBuilder.DropColumn(
                name: "Created",
                table: "User");

            migrationBuilder.DropColumn(
                name: "DateOfBirth",
                table: "User");

            migrationBuilder.DropColumn(
                name: "Gender",
                table: "User");

            migrationBuilder.DropColumn(
                name: "Interests",
                table: "User");

            migrationBuilder.DropColumn(
                name: "Introduction",
                table: "User");

            migrationBuilder.DropColumn(
                name: "KnownAs",
                table: "User");

            migrationBuilder.DropColumn(
                name: "LastActive",
                table: "User");

            migrationBuilder.DropColumn(
                name: "LookingFor",
                table: "User");

            migrationBuilder.AlterColumn<int>(
                name: "Username",
                table: "User",
                nullable: false,
                oldClrType: typeof(string),
                oldNullable: true);
        }
    }
}

尝试删除我更新的数据库迁移，从头添加迁移，尝试执行 dotnet ef database update 命令并得到消息：

SQLite does not support this migration operation ('AlterColumnOperation'). For more information, see http://go.microsoft.com/fwlink/?LinkId=723262.

我不知道该怎么做才能在 SQL lite 中添加迁移，这就是问题出现的原因。

如何更改列？因为大概就是这样。

标签： c#asp.netasp.net-core

Answer 1

您可以删除数据库和所有现有迁移并再次运行，add-migration InitialCreate这将从头开始创建新迁移，因此不会有任何列需要更改。