C# 无法跟踪实体类型的实例,因为另一个实例。。。更新数据库时发生EF核心错误
服务:C# 无法跟踪实体类型的实例,因为另一个实例。。。更新数据库时发生EF核心错误,c#,sql-server,entity-framework,C#,Sql Server,Entity Framework,服务: public Cart AddProductToCart(Product product, Cart cart) { var productExist = _dbContexet.CartProduct.Where(cp => cp.ProductId == product.Id).FirstOrDefault(); var quantityOfCart = _dbContexet.CartProduct.Where(cp => cp.CartId == ca
public Cart AddProductToCart(Product product, Cart cart)
{
var productExist = _dbContexet.CartProduct.Where(cp => cp.ProductId == product.Id).FirstOrDefault();
var quantityOfCart = _dbContexet.CartProduct.Where(cp => cp.CartId == cart.Id).FirstOrDefault().Quantity;
CartProduct cartProduct = new CartProduct();
cartProduct.CartId = cart.Id;
cartProduct.ProductId = product.Id;
if (productExist != null)
{
cartProduct.Quantity = quantityOfCart + 1;
_dbContexet.Attach(cartProduct).State = EntityState.Modified;
}
else
{
cartProduct.Cart = cart;
cartProduct.Product = product;
_dbContexet.CartProduct.Add(cartProduct);
}
_dbContexet.SaveChanges();
return cart;
}
完全错误:
InvalidOperationException:实体类型“CartProduct”的实例
无法跟踪,因为另一个实例的键值与
{'CartId','ProductId'}已被跟踪。连接时
现有实体,请确保只有一个实体实例具有给定的
随附关键值。考虑使用
“DbContextOptions Builder.EnableSensivedAtalogging”以查看
相互冲突的键值
我有多对多和表CartProduct
我想检查产品是否存在,如果存在只更新数量,但我得到这个错误
Eddit:
产品:
public partial class Product
{
public int Id { get; set; }
public string Name { get; set; }
public decimal Price { get; set; }
public string Category { get; set; }
public decimal CostToMake { get; set; }
public decimal FinalPrice { get; set; }
//public int? OrderId { get; set; }
public virtual Order Order { get; set; }
public List<CartProduct> CartProduct { get; set; }
}
弗伦塔皮:
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.HasAnnotation("Relational:Collation", "Cyrillic_General_CI_AS");
modelBuilder.Entity<Day>(entity =>
{
entity.Property(e => e.Date).HasColumnType("date");
entity.Property(e => e.MostCommonCategory)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(false);
entity.Property(e => e.MostCommonProduct)
.IsRequired()
.HasMaxLength(100)
.IsUnicode(false);
entity.Property(e => e.TotalMade).HasColumnType("decimal(18, 3)");
entity.Property(e => e.TotalSpent).HasColumnType("decimal(18, 3)");
});
modelBuilder.Entity<Order>(entity =>
{
entity.Property(e => e.Date).HasColumnType("date");
entity.Property(e => e.Status)
.IsRequired()
.HasMaxLength(100)
.IsUnicode(false);
entity.Property(e => e.Name).HasMaxLength(100);
entity.Property(e => e.Address).HasMaxLength(150);
entity.Property(e => e.PhoneNumber).HasMaxLength(20);
});
modelBuilder.Entity<Product>(entity =>
{
entity.HasIndex(e => e.OrderId, "IX_Products_OrderId");
entity.Property(e => e.Category)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(false);
entity.Property(e => e.CostToMake).HasColumnType("decimal(18, 3)");
entity.Property(e => e.FinalPrice).HasColumnType("decimal(18, 3)");
entity.Property(e => e.Name)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(false);
entity.Property(e => e.Price).HasColumnType("decimal(18, 3)");
entity.HasOne(d => d.Order)
.WithMany(p => p.Products)
.HasForeignKey(d => d.OrderId);
});
modelBuilder.Entity<Cart>(entity => {
entity.HasKey(e => e.Id);
entity.HasOne(e => e.User)
.WithOne(e => e.Cart)
.HasForeignKey<AppUser>(e => e.CartId);
});
modelBuilder.Entity<CartProduct>()
.HasKey(e => new { e.CartId, e.ProductId });
modelBuilder.Entity<CartProduct>()
.HasOne(t => t.Cart)
.WithMany(t => t.CartProduct)
.HasForeignKey(t => t.ProductId);
modelBuilder.Entity<CartProduct>()
.HasOne(t => t.Product)
.WithMany(t => t.CartProduct)
.HasForeignKey(t => t.CartId);
OnModelCreatingPartial(modelBuilder);
}
模型创建时受保护的覆盖无效(ModelBuilder ModelBuilder)
{
基于模型创建(modelBuilder);
HasAnnotation(“关系:排序规则”、“西里尔文”通用词“);
modelBuilder.Entity(Entity=>
{
entity.Property(e=>e.Date).HasColumnType(“日期”);
属性(e=>e.MostCommonCategory)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(假);
Property(e=>e.MostCommonProduct)
.IsRequired()
.HasMaxLength(100)
.IsUnicode(假);
Property(e=>e.totalmake.HasColumnType(“decimal(18,3)”);
Property(e=>e.totalExplored).HasColumnType(“decimal(18,3)”);
});
modelBuilder.Entity(Entity=>
{
entity.Property(e=>e.Date).HasColumnType(“日期”);
entity.Property(e=>e.Status)
.IsRequired()
.HasMaxLength(100)
.IsUnicode(假);
Property(e=>e.Name).HasMaxLength(100);
Property(e=>e.Address).HasMaxLength(150);
Property(e=>e.PhoneNumber).HasMaxLength(20);
});
modelBuilder.Entity(Entity=>
{
entity.HasIndex(e=>e.OrderId,“IX_产品_OrderId”);
entity.Property(e=>e.Category)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(假);
Property(e=>e.CostToMake).HasColumnType(“decimal(18,3)”);
Property(e=>e.FinalPrice).HasColumnType(“decimal(18,3)”);
entity.Property(e=>e.Name)
.IsRequired()
.HasMaxLength(50)
.IsUnicode(假);
Property(e=>e.Price).HasColumnType(“decimal(18,3)”);
entity.HasOne(d=>d.Order)
.有许多(p=>p.产品)
.HasForeignKey(d=>d.OrderId);
});
modelBuilder.Entity(Entity=>{
entity.HasKey(e=>e.Id);
entity.HasOne(e=>e.User)
.WithOne(e=>e.Cart)
.HasForeignKey(e=>e.CartId);
});
modelBuilder.Entity()
.HasKey(e=>new{e.CartId,e.ProductId});
modelBuilder.Entity()
.HasOne(t=>t.Cart)
.WithMany(t=>t.CartProduct)
.HasForeignKey(t=>t.ProductId);
modelBuilder.Entity()
.HasOne(t=>t.Product)
.WithMany(t=>t.CartProduct)
.HasForeignKey(t=>t.CartId);
OnModelCreatingPartial(modelBuilder);
}
您的错误是因为:
cartProduct.CartId = cart.Id;
cartProduct.ProductId = product.Id;
在现实中,这与:
cartProduct.Cart = cart;
cartProduct.Product = product;
因此,只需从代码中删除:
cartProduct.Cart = cart;
cartProduct.Product = product;
您可以使用EF功能以不同的方式执行某些操作
public Cart AddProductToCart(Product product, Cart cart)
{
var product = _dbContexet.Product.Where(cp => cp.ProductId == product.Id).Include(x => x.CartProduct).FirstOrDefault();
var quantityOfCart = _dbContexet.CartProduct.Where(cp => cp.CartId == cart.Id).FirstOrDefault().Quantity;
var cartProduct = product.CartProduct.Where(x=>x.CartId == cart.id).FirstOrDefault();
if (cartProduct != null)
{
cartProduct.Quantity = quantityOfCart + 1;
}
else
{
product.CartProduct.Add(new CartProduct { CartId = cart.id });
}
//_dbContexet.Update(product) if you are using QueryTrackingBehavior.NoTracking
_dbContexet.SaveChanges();
return cart;
}
你能提供类
Cart
,Product
,CartProduct
?@OxQ我用类和fluent api编辑了这篇文章。
cartProduct.Cart = cart;
cartProduct.Product = product;
public Cart AddProductToCart(Product product, Cart cart)
{
var product = _dbContexet.Product.Where(cp => cp.ProductId == product.Id).Include(x => x.CartProduct).FirstOrDefault();
var quantityOfCart = _dbContexet.CartProduct.Where(cp => cp.CartId == cart.Id).FirstOrDefault().Quantity;
var cartProduct = product.CartProduct.Where(x=>x.CartId == cart.id).FirstOrDefault();
if (cartProduct != null)
{
cartProduct.Quantity = quantityOfCart + 1;
}
else
{
product.CartProduct.Add(new CartProduct { CartId = cart.id });
}
//_dbContexet.Update(product) if you are using QueryTrackingBehavior.NoTracking
_dbContexet.SaveChanges();
return cart;
}