Fatal编程技术网
  • csharp/
  • C# EF Core无法在表中插入标识列的显式值

C# EF Core无法在表中插入标识列的显式值

c# asp.net-core entity-framework-core

C# EF Core无法在表中插入标识列的显式值,c#,asp.net-core,entity-framework-core,C#,Asp.net Core,Entity Framework Core,我已经看到了，但以下错误并未消失： 当identity\u insert设置为OFF时，无法在表“Products”中为identity列插入显式值 我试过的是： [Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] public int Id { get; set; } 此外，我还尝试设置为None： [DatabaseGenerated(DatabaseGeneratedOption.None)] public int Id

我已经看到了，但以下错误并未消失：

当identity\u insert设置为OFF时，无法在表“Products”中为identity列插入显式值

我试过的是：

[Key, DatabaseGenerated(DatabaseGeneratedOption.Identity)] 
public int Id { get; set; }
此外，我还尝试设置为
None
：

[DatabaseGenerated(DatabaseGeneratedOption.None)]
public int Id { get; set; }

T-SQL
代码如下所示：

CREATE TABLE Orders
(
    Id INT IDENTITY(1,1),
    DatePlaced datetime NOT NULL,   
    CONSTRAINT PK_Order_Id PRIMARY KEY (Id)
)

CREATE TABLE OrderItems
(
    Id INT IDENTITY(1,1),
    IdOrder INT NOT NULL
        CONSTRAINT FK_OrderItems_IdOrder__Orders_Id FOREIGN KEY(IdOrder) REFERENCES Orders(Id),
    IdProduct INT NOT NULL
        CONSTRAINT FK_OrderItems_IdProduct__Products_Id FOREIGN KEY(IdProduct) REFERENCES Products(Id),
    Quantity INT NOT NULL,
    TotalPrice decimal (18,2),  
    CONSTRAINT PK_OrderItem_Id PRIMARY KEY (Id)
)

CREATE TABLE Products
(
    Id INT IDENTITY(1,1),
    Name varchar(100), 
    CONSTRAINT PK_Product_Id PRIMARY KEY (Id)
)

public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public partial class OrderItem
{
    public int Id { get; set; }

    public int Quantity { get; set; }

    [Column(TypeName = "decimal(18,2)")]
    public decimal? TotalPrice { get; set; }

    public virtual Order Order { get; set; }
    public virtual Product Product { get; set; }
}

public partial class Product
{
    public Product() { }

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }       

    public string Name { get; set; }
}

public async Task Add(Order order)
{
    order.Customer = _context.Customers.Find(order.Customer.Id);    
    await _context.AddAsync(order);
    await _context.SaveChangesAsync();
}

public async Task Add(Order order)
{            
    _context.Attach(order.Customer);
    foreach (var orderItem in order.OrderItems)
    {
        _context.Attach(orderItem.Product);
    }            
    await _context.Orders.AddAsync(order);
}
模型类如下所示：

CREATE TABLE Orders
(
    Id INT IDENTITY(1,1),
    DatePlaced datetime NOT NULL,   
    CONSTRAINT PK_Order_Id PRIMARY KEY (Id)
)

CREATE TABLE OrderItems
(
    Id INT IDENTITY(1,1),
    IdOrder INT NOT NULL
        CONSTRAINT FK_OrderItems_IdOrder__Orders_Id FOREIGN KEY(IdOrder) REFERENCES Orders(Id),
    IdProduct INT NOT NULL
        CONSTRAINT FK_OrderItems_IdProduct__Products_Id FOREIGN KEY(IdProduct) REFERENCES Products(Id),
    Quantity INT NOT NULL,
    TotalPrice decimal (18,2),  
    CONSTRAINT PK_OrderItem_Id PRIMARY KEY (Id)
)

CREATE TABLE Products
(
    Id INT IDENTITY(1,1),
    Name varchar(100), 
    CONSTRAINT PK_Product_Id PRIMARY KEY (Id)
)

public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public partial class OrderItem
{
    public int Id { get; set; }

    public int Quantity { get; set; }

    [Column(TypeName = "decimal(18,2)")]
    public decimal? TotalPrice { get; set; }

    public virtual Order Order { get; set; }
    public virtual Product Product { get; set; }
}

public partial class Product
{
    public Product() { }

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }       

    public string Name { get; set; }
}

public async Task Add(Order order)
{
    order.Customer = _context.Customers.Find(order.Customer.Id);    
    await _context.AddAsync(order);
    await _context.SaveChangesAsync();
}

public async Task Add(Order order)
{            
    _context.Attach(order.Customer);
    foreach (var orderItem in order.OrderItems)
    {
        _context.Attach(orderItem.Product);
    }            
    await _context.Orders.AddAsync(order);
}
我想要的是保存
订单
和
订单项
。保存代码如下所示：

CREATE TABLE Orders
(
    Id INT IDENTITY(1,1),
    DatePlaced datetime NOT NULL,   
    CONSTRAINT PK_Order_Id PRIMARY KEY (Id)
)

CREATE TABLE OrderItems
(
    Id INT IDENTITY(1,1),
    IdOrder INT NOT NULL
        CONSTRAINT FK_OrderItems_IdOrder__Orders_Id FOREIGN KEY(IdOrder) REFERENCES Orders(Id),
    IdProduct INT NOT NULL
        CONSTRAINT FK_OrderItems_IdProduct__Products_Id FOREIGN KEY(IdProduct) REFERENCES Products(Id),
    Quantity INT NOT NULL,
    TotalPrice decimal (18,2),  
    CONSTRAINT PK_OrderItem_Id PRIMARY KEY (Id)
)

CREATE TABLE Products
(
    Id INT IDENTITY(1,1),
    Name varchar(100), 
    CONSTRAINT PK_Product_Id PRIMARY KEY (Id)
)

public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public partial class OrderItem
{
    public int Id { get; set; }

    public int Quantity { get; set; }

    [Column(TypeName = "decimal(18,2)")]
    public decimal? TotalPrice { get; set; }

    public virtual Order Order { get; set; }
    public virtual Product Product { get; set; }
}

public partial class Product
{
    public Product() { }

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }       

    public string Name { get; set; }
}

public async Task Add(Order order)
{
    order.Customer = _context.Customers.Find(order.Customer.Id);    
    await _context.AddAsync(order);
    await _context.SaveChangesAsync();
}

public async Task Add(Order order)
{            
    _context.Attach(order.Customer);
    foreach (var orderItem in order.OrderItems)
    {
        _context.Attach(orderItem.Product);
    }            
    await _context.Orders.AddAsync(order);
}
和
OrderService
class:

    public async Task<OrderDto> Add(OrderDto orderDto)
    {
        var order = _mapper.Map<Order>(orderDto);
        await _orderRepository.Add(order);        
        orderDto.Id = order.Id;
        return orderDto;

    }

公共异步任务添加（OrderDto到OrderDto）
{
var order=\u mapper.Map（orderDto）；
wait_orderRepository.Add（订单）；
orderDto.Id=order.Id；
返回订单到；
}
请告诉我我做错了什么？请不要关闭我的问题，因为它不是重复的。

这种行为的原因是
Automapper
创建了一个新实例，实体框架认为POCO都是应该插入的新实体

因此，解决方案是
将现有实体附加到`DbContext

因此，解决方案如下所示：


CREATE TABLE Orders
(
    Id INT IDENTITY(1,1),
    DatePlaced datetime NOT NULL,   
    CONSTRAINT PK_Order_Id PRIMARY KEY (Id)
)

CREATE TABLE OrderItems
(
    Id INT IDENTITY(1,1),
    IdOrder INT NOT NULL
        CONSTRAINT FK_OrderItems_IdOrder__Orders_Id FOREIGN KEY(IdOrder) REFERENCES Orders(Id),
    IdProduct INT NOT NULL
        CONSTRAINT FK_OrderItems_IdProduct__Products_Id FOREIGN KEY(IdProduct) REFERENCES Products(Id),
    Quantity INT NOT NULL,
    TotalPrice decimal (18,2),  
    CONSTRAINT PK_OrderItem_Id PRIMARY KEY (Id)
)

CREATE TABLE Products
(
    Id INT IDENTITY(1,1),
    Name varchar(100), 
    CONSTRAINT PK_Product_Id PRIMARY KEY (Id)
)



public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public partial class OrderItem
{
    public int Id { get; set; }

    public int Quantity { get; set; }

    [Column(TypeName = "decimal(18,2)")]
    public decimal? TotalPrice { get; set; }

    public virtual Order Order { get; set; }
    public virtual Product Product { get; set; }
}

public partial class Product
{
    public Product() { }

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }       

    public string Name { get; set; }
}



public async Task Add(Order order)
{
    order.Customer = _context.Customers.Find(order.Customer.Id);    
    await _context.AddAsync(order);
    await _context.SaveChangesAsync();
}



public async Task Add(Order order)
{            
    _context.Attach(order.Customer);
    foreach (var orderItem in order.OrderItems)
    {
        _context.Attach(orderItem.Product);
    }            
    await _context.Orders.AddAsync(order);
}


整个代码如下所示

服务层：


public async Task<OrderDto> Add(OrderDto orderDto)
{
    var order = _mapper.Map<Order>(orderDto);
    await _orderRepository.Add(order);        
    orderDto.Id = order.Id;
    return orderDto;
}



这种行为的原因是
Automapper
创建了一个新实例，实体框架认为POCO都是应该插入的新实体

因此，解决方案是
将现有实体附加到`DbContext

因此，解决方案如下所示：


CREATE TABLE Orders
(
    Id INT IDENTITY(1,1),
    DatePlaced datetime NOT NULL,   
    CONSTRAINT PK_Order_Id PRIMARY KEY (Id)
)

CREATE TABLE OrderItems
(
    Id INT IDENTITY(1,1),
    IdOrder INT NOT NULL
        CONSTRAINT FK_OrderItems_IdOrder__Orders_Id FOREIGN KEY(IdOrder) REFERENCES Orders(Id),
    IdProduct INT NOT NULL
        CONSTRAINT FK_OrderItems_IdProduct__Products_Id FOREIGN KEY(IdProduct) REFERENCES Products(Id),
    Quantity INT NOT NULL,
    TotalPrice decimal (18,2),  
    CONSTRAINT PK_OrderItem_Id PRIMARY KEY (Id)
)

CREATE TABLE Products
(
    Id INT IDENTITY(1,1),
    Name varchar(100), 
    CONSTRAINT PK_Product_Id PRIMARY KEY (Id)
)



public partial class Order
{
    public Order()
    {
        OrderItems = new HashSet<OrderItem>();
    }

    public int Id { get; set; }

    public DateTime DatePlaced { get; set; }

    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public partial class OrderItem
{
    public int Id { get; set; }

    public int Quantity { get; set; }

    [Column(TypeName = "decimal(18,2)")]
    public decimal? TotalPrice { get; set; }

    public virtual Order Order { get; set; }
    public virtual Product Product { get; set; }
}

public partial class Product
{
    public Product() { }

    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int Id { get; set; }       

    public string Name { get; set; }
}



public async Task Add(Order order)
{
    order.Customer = _context.Customers.Find(order.Customer.Id);    
    await _context.AddAsync(order);
    await _context.SaveChangesAsync();
}



public async Task Add(Order order)
{            
    _context.Attach(order.Customer);
    foreach (var orderItem in order.OrderItems)
    {
        _context.Attach(orderItem.Product);
    }            
    await _context.Orders.AddAsync(order);
}


整个代码如下所示

服务层：


public async Task<OrderDto> Add(OrderDto orderDto)
{
    var order = _mapper.Map<Order>(orderDto);
    await _orderRepository.Add(order);        
    orderDto.Id = order.Id;
    return orderDto;
}



另一个解决方案是使用
\u mapper.Map（sourceProperty，destinationProperty）。这不会更改引用。但是，在设置配置时，请确保忽略不希望映射的属性（即主键）

e、 g.在映射配置文件类的构造函数下：


CreateMap<SourceType, DestinationType>()
.ForMember(destination => destination.PK, options => options.Ignore());



CreateMap（）
.ForMember（destination=>destination.PK，options=>options.Ignore（））；

另一种解决方案是使用
\u mapper.Map（sourceProperty，destinationProperty）。这不会更改引用。但是，在设置配置时，请确保忽略不希望映射的属性（即主键）

e、 g.在映射配置文件类的构造函数下：


CreateMap<SourceType, DestinationType>()
.ForMember(destination => destination.PK, options => options.Ignore());



CreateMap（）
.ForMember（destination=>destination.PK，options=>options.Ignore（））；

该错误适用于
产品
表，但您显示的代码适用于
订单
和
订单项
表。你能展示一下
产品的代码吗？@devNull，请看我更新的问题。插入产品本身似乎是一个错误。我不是EF专家，我会评论而不是回答，但我相信
AddAsync
会将实体添加到添加状态的上下文中，因此它会尝试插入它。它已经有了一个id，因为您刚刚（大概）找到了它的
。我认为您可以删除
Add（）
方法中的第二行代码。@GertArnold您的意思是再次插入产品吗？错误是针对
Products
表的，但您显示的代码是针对
Orders
和
OrderItems
表的。你能展示一下
产品的代码吗？@devNull，请看我更新的问题。插入产品本身似乎是一个错误。我不是EF专家，我会评论而不是回答，但我相信
AddAsync
会将实体添加到添加状态的上下文中，因此它会尝试插入它。它已经有了一个id，因为您刚刚（大概）找到了它的
。我想您可以删除
Add（）
方法中的第二行代码。@GertArnold您是说产品会再次插入吗？