问题描述
我在这里拉出我的头发。我见过的解决方案，在这里关闭级联删除上，但我不能执行。我不知道我做错了什么，但我不断收到以下错误：
System.Data.Entity.ModelConfiguration.EntityTypeConfiguration'不包含'WillCascadeOnDelete'，没有扩展方法'WillCascadeOnDelete接受型System.Data.Entity.ModelConfiguration.EntityTypeConfiguration'的第一个参数的定义可以发现（是否缺少using指令或程序集引用？）
我已经添加了必要的命名空间，但我不认为这是一个选项中的任意位置智能感知，我不成气候搜索。我在VS 2010 MVC 3
使用系统;
使用System.Collections.Generic;
使用System.Linq的;
使用的System.Web;
使用vf2.Models;
使用vf2.Models.LinkTables;
使用vf2.Models.Requests;
使用System.Data.Entity的;
使用System.Data.Entity.ModelConfiguration.Conventions;
使用System.Data.Entity.ModelConfiguration.Configuration;
使用System.Data.Entity.ModelConfiguration;
使用vf2.Models.Reporting;
使用vf2.Models.POSObj;命名空间vf2.Models
{
公共类vfContext：的DbContext
{
公共DbSet＆LT;应用＆GT;应用{搞定;组; }
公共DbSet＆LT;产地＆GT;起源{搞定;组; }
公共DbSet＆LT; WineType＆GT; WineTypes {搞定;组; }
公共DbSet＆LT; VarType函数＆GT; VarTypes {搞定;组; }
公共DbSet＆LT;葡萄酒与GT;葡萄酒{搞定;组; }
公共DbSet＆LT;复古与GT;年份{搞定;组; } 公共DbSet＆LT;分发商GT;经销商{搞定;组; }
公共DbSet＆LT;进口商和GT;进口商{搞定;组; }
公共DbSet＆LT;生产者＆GT;生产者{搞定;组; }
公共DbSet＆LT;刊物及GT;出版物{搞定;组; }
公共DbSet＆LT;回顾与GT;评论{搞定;组; }
公共DbSet＆LT;＆用户类型GT; UserTypes {搞定;组; }
公共DbSet＆LT;餐厅＆GT;餐馆{搞定;组; } 公共DbSet＆LT; WineListChangeRate＆GT; WineListChangeRates {搞定;组; }
公共DbSet＆LT; MenuChangeRate＆GT; MenuChangeRates {搞定;组; }
公共DbSet＆LT; WineListCount＆GT; WineListCounts {搞定;组; } 公共DbSet＆LT; UserObj＆GT; UserObjs {搞定;组; }
公共DbSet＆LT; ProducerUser＆GT; ProducerUsers {搞定;组; }
公共DbSet＆LT; DistributorUser＆GT; DistributorUsers {搞定;组; }
公共DbSet＆LT; RestaurantUser＆GT; RestaurantUsers {搞定;组; } 公共DbSet＆LT; ProducerEditRequest＆GT; ProducerEditRequests {搞定;组; }
公共DbSet＆LT; RequestStatus＆GT; RequestStatuses {搞定;组; }
公共DbSet＆LT; VOAVIRequest＆GT; VOAVIRequests {搞定;组; } 公共DbSet＆LT; POS＆GT; POSS {搞定;组; }
公共DbSet＆LT;购物车和GT;车{搞定;组; }
公共DbSet＆LT; FutureUser＆GT; FutureUsers {搞定;组; }
公共DbSet＆LT;＆文件GT;文档{搞定;组; }
公共DbSet＆LT;！DOCTYPE＆GT;文档类型{搞定;组; } 公共DbSet＆LT; WineVisit＆GT; WineVisits {搞定;组; }
保护覆盖无效OnModelCreating（DbModelBuilder模型构建器）
{ modelBuilder.Entity＆LT;回顾及GT;（）WillCascadeOnDelete（假）。
//错误在这里！ base.OnModelCreating（模型构建器）;
}
}
}
级联删除是一个关系的构造实体/表不。因此， WillCascadeOnDelete 是 CascadableNavigationPropertyConfiguration 的方法。使用案例：
modelBuilder.Entity＆LT;回顾及GT;（）
.HasRequired（R =＆GT; r.Wine）
.WithMany（）
.WillCascadeOnDelete（假）;
这意味着，如果酒是从目录中的数据库中删除，这是审查不应与酒一起删除。这就是这个特定的关系的性质，而不是评论表。
在这种情况下尝试删除有评论将导致违反外键约束，当然异常的酒，但是那是你平时想如果禁用级联删除所需关系（不允许以删除有评论葡萄酒，只允许其用于哪些还没有任何葡萄酒...）。
I'm pulling out my hair here. I've seen the solutions to turning off cascade on delete here, but I can't implement it. I don't know what I'm doing wrong here, but I keep getting the below error:
'System.Data.Entity.ModelConfiguration.EntityTypeConfiguration' does not contain a definition for 'WillCascadeOnDelete' and no extension method 'WillCascadeOnDelete' accepting a first argument of type 'System.Data.Entity.ModelConfiguration.EntityTypeConfiguration' could be found (are you missing a using directive or an assembly reference?)
I've added the necessary namespaces, but I don't see it as an option anywhere in the intellisense and I'm not getting anywhere searching. I'm in VS 2010 MVC 3
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using vf2.Models;
using vf2.Models.LinkTables;
using vf2.Models.Requests;
using System.Data.Entity;
using System.Data.Entity.ModelConfiguration.Conventions;
using System.Data.Entity.ModelConfiguration.Configuration;
using System.Data.Entity.ModelConfiguration;
using vf2.Models.Reporting;
using vf2.Models.POSObj;
namespace vf2.Models
{
public class vfContext : DbContext
{
public DbSet<App> Apps { get; set; }
public DbSet<Origin> Origins { get; set; }
public DbSet<WineType> WineTypes { get; set; }
public DbSet<VarType> VarTypes { get; set; }
public DbSet<Wine> Wines { get; set; }
public DbSet<Vintage> Vintages { get; set; }
public DbSet<Distributor> Distributors { get; set; }
public DbSet<Importer> Importers { get; set; }
public DbSet<Producer> Producers { get; set; }
public DbSet<Publication> Publications { get; set; }
public DbSet<Review> Reviews { get; set; }
public DbSet<UserType> UserTypes { get; set; }
public DbSet<Restaurant> Restaurants { get; set; }
public DbSet<WineListChangeRate> WineListChangeRates { get; set; }
public DbSet<MenuChangeRate> MenuChangeRates { get; set; }
public DbSet<WineListCount> WineListCounts { get; set; }
public DbSet<UserObj> UserObjs { get; set; }
public DbSet<ProducerUser> ProducerUsers { get; set; }
public DbSet<DistributorUser> DistributorUsers { get; set; }
public DbSet<RestaurantUser> RestaurantUsers { get; set; }
public DbSet<ProducerEditRequest> ProducerEditRequests { get; set; }
public DbSet<RequestStatus> RequestStatuses { get; set; }
public DbSet<VOAVIRequest> VOAVIRequests { get; set; }
public DbSet<POS> POSs { get; set; }
public DbSet<Cart> Carts { get; set; }
public DbSet<FutureUser> FutureUsers { get; set; }
public DbSet<Doc> Docs { get; set; }
public DbSet<DocType> DocTypes { get; set; }
public DbSet<WineVisit> WineVisits { get; set; }
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<Review>().WillCascadeOnDelete(false);
//error here!
base.OnModelCreating(modelBuilder);
}
}
}
"Cascading delete" is a configuration of a relationship, not of an entity/table. Hence WillCascadeOnDelete is a method of CascadableNavigationPropertyConfiguration. Use case example:
modelBuilder.Entity<Review>()
.HasRequired(r => r.Wine)
.WithMany()
.WillCascadeOnDelete(false);
It means that if a wine is deleted from the catalog in the database, it's reviews should not be deleted together with the wine. That's a property of this specific relationship, not of the Reviews table.
In this case trying to delete a wine which has reviews would result in a foreign key constraint violation and exception of course, but that is what you usually want when you disable cascading delete on a required relationship ("Don't allow to delete a wine which has reviews, only allow it for wines which haven't any...").
这篇关于设置表级WillCascadeOnDelete不可用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！