EF代码优先：INSERT语句与FOREIGN KEY约束冲突 [英] EF Code First: The INSERT statement conflicted with the FOREIGN KEY constraint

问题描述

这是我使用微风/角度/ EF的试用项目。我不明白为什么会收到此错误，因为我认为我以前使用过相同的结构。

This is my trial project using breeze/angular/EF. I don't understand why I get this error because I thought I had the same structure working before.

public class TshirtOrder
{
    public int Id { get; set; }
    public string Name { get; set; }
    public virtual ICollection<OrderItem> OrderItems { get; set; }
}

public class OrderItem
{
    public int Id { get; set; }
    [ForeignKey("Type")]
    public int TshirtTypeId { get; set; }
    public virtual TshirtType Type { get; set; }
    [ForeignKey("Size")]
    public int TshirtSizeId { get; set; }
    public virtual TshirtSize Size { get; set; }
    public double UnitPrice { get; set; }
    public int Quantity { get; set; }

    [ForeignKey("TshirtOrder")]
    public int TshirtOrderId { get; set; }
    public TshirtOrder TshirtOrder { get; set; }
}

表定义如下：

CREATE TABLE [dbo].[TshirtOrder] (
    [Id]         INT            IDENTITY (1, 1) NOT NULL,
    [Name]       NVARCHAR (MAX) NULL,
    CONSTRAINT [PK_dbo.TshirtOrder] PRIMARY KEY CLUSTERED ([Id] ASC)
);

CREATE TABLE [dbo].[OrderItem] (
    [Id]            INT        IDENTITY (1, 1) NOT NULL,
    [TshirtTypeId]  INT        NOT NULL,
    [TshirtSizeId]  INT        NOT NULL,
    [UnitPrice]     FLOAT (53) NOT NULL,
    [Quantity]      INT        NOT NULL,
    [TshirtOrderId] INT        NOT NULL,
    CONSTRAINT [PK_dbo.OrderItem] PRIMARY KEY CLUSTERED ([Id] ASC),
    CONSTRAINT [FK_dbo.OrderItem_dbo.TshirtType_TshirtTypeId] FOREIGN KEY ([TshirtTypeId]) REFERENCES [dbo].[TshirtType] ([Id]) ON DELETE CASCADE,
    CONSTRAINT [FK_dbo.OrderItem_dbo.TshirtSize_TshirtSizeId] FOREIGN KEY ([TshirtSizeId]) REFERENCES [dbo].[TshirtSize] ([Id]) ON DELETE CASCADE,
    CONSTRAINT [FK_dbo.OrderItem_dbo.TshirtOrder_TshirtOrderId] FOREIGN KEY ([TshirtOrderId]) REFERENCES [dbo].[TshirtOrder] ([Id]) ON DELETE CASCADE
);

这是如何将其保存在Breeze数据上下文中的：

This is how it gets saved in Breeze datacontext:

function _createTshirtOrder() {
    var order = manager.createEntity("TshirtOrder");

    order.orderItems.push(createOrderItem(lookups.tshirtTypes[0], lookups.tshirtSizes[0], 10));
    common.saveEntity(order);
    return order;

    function createOrderItem(type, size, unitPrice) {
        var item = manager.createEntity("OrderItem");
        item.type = type;
        item.size = size;
        item.unitPrice = unitPrice;
        item.quantity = 0;
        return item;
    }
}

这里是确切的错误：

{"The INSERT statement conflicted with the FOREIGN KEY constraint \"FK_dbo.OrderItem_dbo.TshirtOrder_TshirtOrderId\". The conflict occurred in database \"dbbb\", table \"dbo.TshirtOrder\", column 'Id'.\r\nThe statement has been terminated."}

那么，问题出在哪里？

推荐答案

我不知道您的 saveEntity方法是什么样的，但是我猜它叫

I don't know what your "saveEntity" method looks like but I'm guessing it calls

entityManager.saveChanges([order]);

如果是这样，那么问题是您只保存订单，而不是orderItem，因为您告诉它只保存一个订单。 Breeze会跟踪对entityManager的任何更改，因此通常更好的解决方案是让Breeze为您解决问题。即

If so, then the problem is that you are only saving the order and NOT the orderItem as well, because you told it to only save the one order. Breeze tracks any changes to the entityManager so a better solution is usually to just let Breeze figure it out for you. i.e.

entityManager.saveChanges();  or entityManager.saveChanges(null, ... );

这会将所有添加，修改或删除的记录保存在entityManager中。

Which will save all added, modified or deleted records in the entityManager.

或者，您可以指定要保存的所有实体。

Alternately you can specify all of the entities you want saved.

entityManager.saveChanges([order, orderItem1, orderItem2, ... ]);

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