可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN KEY约束 [英] may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints

问题描述

实体框架核心

在执行更新数据库时抛出错误

Throwing error while doing update-database

错误：-
在表'UserRoleRelationship'上引入FOREIGN KEY约束'FK_UserRoleRelationship_UserRoels_ParentUserRoleId'可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN KEY约束。
无法创建约束或索引。

Error:- Introducing FOREIGN KEY constraint 'FK_UserRoleRelationship_UserRoels_ParentUserRoleId' on table 'UserRoleRelationship' may cause cycles or multiple cascade paths. Specify ON DELETE NO ACTION or ON UPDATE NO ACTION, or modify other FOREIGN KEY constraints. Could not create constraint or index.

public class UserRoleRelationship 
{
    [Key]
    public int Id { get; set; }
    [Required]
    public Guid UserRoleRelationshipId { get; set; }

    public virtual UserRole ChildUserRole { get; set; }
    public int ChildUserRoleId { get; set; }

    public virtual UserRole ParentUserRole { get; set; }
    public int ParentUserRoleId { get; set; }

}

public class UserRole 
{
    [Key]
    public int Id { get; set; }
    [Required]
    public Guid UserRoleId { get; set; }
    public virtual Role Role { set; get; }
    public int RoleId { set; get; }
    public virtual U.User User { set; get; }
    public int UserId { set; get; }
}

推荐答案

用于您当前的模型设计，它将在下面创建迁移：

For your current model design, it will create migration below:

            migrationBuilder.AddForeignKey(
            name: "FK_UserRoleRelationship_UserRole_ChildUserRoleId",
            table: "UserRoleRelationship",
            column: "ChildUserRoleId",
            principalTable: "UserRole",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

        migrationBuilder.AddForeignKey(
            name: "FK_UserRoleRelationship_UserRole_ParentUserRoleId",
            table: "UserRoleRelationship",
            column: "ParentUserRoleId",
            principalTable: "UserRole",
            principalColumn: "Id",
            onDelete: ReferentialAction.Cascade);

FK_UserRoleRelationship_UserRole_ChildUserRoleId 和 FK_UserRoleRelationship_UserRole_ParentUserRoleId 都将在删除 UserRoleRelationship 时删除 UserRole 中的记录，这将导致多个级联删除。

FK_UserRoleRelationship_UserRole_ChildUserRoleId and FK_UserRoleRelationship_UserRole_ParentUserRoleId both will delete the records in UserRole when deleting UserRoleRelationship which will cause multiple cascade delete.

要解决此问题，请尝试将 int 设置为 int？如下所示：

For a workaround, try to make int as int? like below:

        public int? ParentUserRoleId { get; set; }

将创建

migrationBuilder.AddForeignKey(
                name: "FK_UserRoleRelationship_UserRole_ParentUserRoleId",
                table: "UserRoleRelationship",
                column: "ParentUserRoleId",
                principalTable: "UserRole",
                principalColumn: "Id",
                onDelete: ReferentialAction.Restrict);

注意

您需要删除 UserRole ，然后删除 UserRoleRelationship

这篇关于可能会导致循环或多个级联路径。指定ON DELETE NO ACTION或ON UPDATE NO ACTION，或修改其他FOREIGN KEY约束的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！