Question

尽管已将其设置为on-delete：外键“ FK_TeamMember_Teams_TeamId”上的“ ReferentialAction.Restrict”，但是在尝试从TeamMember表中删除记录时，它会出现以下错误。您能帮我摆脱这个错误吗？

Microsoft.EntityFrameworkCore.DbUpdateException: An error occurred while updating the entries. 
See the inner exception for details.
---> Microsoft.Data.SqlClient.SqlException (0x80131904): The DELETE statement conflicted with the
REFERENCE constraint "FK_TeamMember_Teams_TeamId". The conflict occurred in database "mot", table 
"dbo.TeamMember", column 'TeamId'. The statement has been terminated.

以下是迁移代码块

  migrationBuilder.CreateTable(
            name: "TeamMember",
            columns: table => new
            {
                Id = table.Column<Guid>(nullable: false),
                MarketingOfficerId = table.Column<Guid>(nullable: false),
                TeamId = table.Column<Guid>(nullable: true)
            },
            constraints: table =>
            {
                table.PrimaryKey("PK_TeamMember", x => x.Id);
                table.ForeignKey(
                    name: "FK_TeamMember_Employees_MarketingOfficerId",
                    column: x => x.MarketingOfficerId,
                    principalTable: "Employees",
                    principalColumn: "Id",
                    onDelete: ReferentialAction.Cascade);
                table.ForeignKey(
                    name: "FK_TeamMember_Teams_TeamId",
                    column: x => x.TeamId,
                    principalTable: "Teams",
                    principalColumn: "Id",
                    onDelete: ReferentialAction.Restrict);
            });

OnModelCreating方法我也使用了以下方法。

modelBuilder.Entity<Team>()
       .HasMany(i => i.TeamMembers)
       .WithOne(i=>i.Team)
       .OnDelete(DeleteBehavior.Restrict);

谢谢

Answer 1

我认为这种行为是正确的，因为当主表删除记录时，它应该删除明细表中的相关记录。保留它毫无意义。数据将是冗余的。但是，如果我们要制作这样的场景，尽管我们在migration.cs中将CascadeDelete设置为Restrict，但它不会按预期工作。下面的文章将有助于理解其行为。

https://docs.microsoft.com/en-us/ef/core/saving/cascade-delete

实体框架核心级联删除错误

1 个答案: