添加多个 class 到购物车 class .net mvc 5
Adding multiple classes to a shopping cart class .net mvc 5
我正在尝试开发一个汽车服务预订应用程序，它允许人们既可以预订汽车进行服务，也可以购买一些零件，这不是必需的，但我收到一个错误，内容如下如下：
SqlException: The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.BasketLines_dbo.Parts_PartID". The conflict occurred in database "aspnet-Noir-20190224082924", table "dbo.Parts", column 'PartId'.
The statement has been terminated.
我的类如下：
部分
public class Part
{
[Key]
public int PartId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public byte[] ImageFile { get; set; }
public string ImageFilePath { get; set; }
public decimal Price { get; set; }
public virtual ICollection<ServicePartMapping>
ServicePartMappings { get; set;}
}
服务
public class Service
{
public int ServiceId { get; set; }
public string Name { get; set; }
public string Type { get; set; }
public decimal Price { get; set; }
public ICollection<Part> Parts { get; set; }
}
ServicePartMapping
public class ServicePartMapping
{
public int ServicePartMappingID { get; set; }
public int PartNumber { get; set; }
public int? ServiceId { get; set; }
public int? ServicePartId { get; set; }
public virtual Service Service { get; set; }
public virtual ServicePart ServicePart { get;
set; }
}
购物篮
public class Basket
{
public int Id { get; set; }
private string BasketID { get; set; }
private const string BasketSessionKey =
"BasketID";
private ApplicationDbContext db = new
ApplicationDbContext();
private string GetBasketID()
{
if
(HttpContext.Current.Session[BasketSessionKey]
== null)
{
if
(!string.IsNullOrWhiteSpace
(HttpContext.Current
.User.Identity.Name))
{
HttpContext.Current
.Session[BasketSessionKey] =
HttpContext.Current
.User.Identity.Name;
}
else
{
Guid tempBasketID = Guid.NewGuid()
HttpContext.Current
.Session[BasketSessionKey]
= tempBasketID.ToString();
}
}
return
HttpContext.Current
.Session[BasketSessionKey].ToString();
}
public static Basket GetBasket()
{
Basket basket = new Basket();
basket.BasketID = basket.GetBasketID();
return basket;
}
public void AddServiceToBasket(int serviceID,
int quantity)
{
var basketLine =
db.BasketLines.FirstOrDefault(b =>
b.BasketID == BasketID && b.ServiceID
== serviceID);
if (basketLine == null)
{
basketLine = new BasketLine
{
ServiceID = serviceID,
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
}
else
{
basketLine.Quantity += quantity;
}
db.SaveChanges();
}
public void AddPartToBasket(int partID, int
quantity)
{
var basketLine =
db.BasketLines.FirstOrDefault(b =>
b.BasketID == BasketID && b.PartId
== partID);
if (basketLine == null)
{
basketLine = new BasketLine
{
PartId = partID,
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
}
else
{
basketLine.Quantity += quantity;
}
db.SaveChanges();
}
public void RemoveLine(int ID)
{
var basketLine = db.BasketLines.FirstOrDefault(b => b.BasketID == BasketID && b.ServiceID
== ID || b.PartId == ID);
if (basketLine != null)
{
db.BasketLines.Remove(basketLine);
}
db.SaveChanges();
}
public void UpdateBasket(List<BasketLine> lines)
{
foreach (var line in lines)
{
var basketLine = db.BasketLines.FirstOrDefault(b => b.BasketID == BasketID &&
b.ServiceID == line.ServiceID);
if (basketLine != null)
{
if (line.Quantity == 0)
{
RemoveLine(line.ServiceID);
}
else
{
basketLine.Quantity = line.Quantity;
}
}
}
db.SaveChanges();
}
public void EmptyBasket()
{
var basketLines = db.BasketLines.Where(b => b.BasketID == BasketID);
foreach (var basketLine in basketLines)
{
db.BasketLines.Remove(basketLine);
}
db.SaveChanges();
}
public List<BasketLine> GetBasketLines()
{
return db.BasketLines.Where(b => b.BasketID == BasketID).ToList();
}
public decimal GetTotalCost()
{
decimal basketTotal = decimal.Zero;
decimal serviceTotal = decimal.Zero;
decimal partTotal = decimal.Zero;
if (GetBasketLines().Count > 0)
{
serviceTotal = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Service.Price
* b.Quantity);
partTotal = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Part.Price
* b.Quantity);
basketTotal = serviceTotal + partTotal;
}
return basketTotal;
}
public int GetNumberOfItems()
{
int numberOfItems = 0;
if (GetBasketLines().Count > 0)
{
numberOfItems = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Quantity);
}
return numberOfItems;
}
public void MigrateBasket(string userName)
{
//find the current basket and store it in memory using ToList()
var basket = db.BasketLines.Where(b => b.BasketID == BasketID).ToList();
//find if the user already has a basket or not and store it in memory using ToList()
var usersBasket = db.BasketLines.Where(b => b.BasketID == userName).ToList();
//if the user has a basket then add the current items to it
if (usersBasket != null)
{
//set the basketID to the username
string prevID = BasketID;
BasketID = userName;
//add the lines in anonymous basket to the user's basket
foreach (var line in basket)
{
AddServiceToBasket(line.ServiceID, line.Quantity);
AddPartToBasket(line.PartId, line.Quantity);
}
//delete the lines in the anonymous basket from the database
BasketID = prevID;
EmptyBasket();
}
else
{
//if the user does not have a basket then just migrate this one
foreach (var basketLine in basket)
{
basketLine.BasketID = userName;
}
db.SaveChanges();
}
HttpContext.Current.Session[BasketSessionKey] = userName;
}
public decimal CreateOrderLines(int orderID)
{
decimal orderTotal = 0;
var basketLines = GetBasketLines();
foreach (var item in basketLines)
{
BillLine BillLine = new BillLine
{
Service = item.Service,
ServiceID = item.ServiceID,
ServiceName = item.Service.Name,
Quantity = item.Quantity,
ServicePrice = item.Service.Price,
BillID = orderID
};
orderTotal += (item.Quantity * item.Service.Price);
db.BillLines.Add(BillLine);
}
db.SaveChanges();
EmptyBasket();
return orderTotal;
}
}
篮筐线
public class BasketLine
{
public int ID { get; set; }
public string BasketID { get; set; }
public int ServiceID { get; set; }
public int PartId { get; set; }
[Range(0, 50, ErrorMessage = "Please enter a quantity between 0 and 50")]
public int Quantity { get; set; }
public DateTime DateCreated { get; set; }
public virtual Service Service { get; set; }
public virtual Part Part { get; set; }
}
假设使用了 EF Code First，异常消息表明您在 BasketLines table 中使用了外键约束，它引用了 [=15] 中的 PartId 主键列=] table，而您正试图在 BasketLines.PartId 列中插入一个值，而该值在 Parts table 中不存在，在此语句中：
basketLine = new BasketLine
{
PartId = partID, // this assignment is the problem source
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
根据检查，您试图在 Service、Part 和 BasketLine 实体之间建立关系，因此我建议为 [=22 添加 ForeignKeyAttribute =] 和 PartId 属性 在 BasketLine 实体中：
public class BasketLine
{
public int ID { get; set; }
public string BasketID { get; set; }
[ForeignKey("Service")]
public int ServiceID { get; set; }
[ForeignKey("Part")]
public int PartId { get; set; }
[Range(0, 50, ErrorMessage = "Please enter a quantity between 0 and 50")]
public int Quantity { get; set; }
public DateTime DateCreated { get; set; }
public virtual Service Service { get; set; }
public virtual Part Part { get; set; }
}
此外，由于声明 BasketLine 需要 Service 和可选的 Part，您也可以尝试像这样修改 DbContext 中的 OnModelCreating() 方法:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<BasketLine>()
.HasOptional(x => x.Part) // can save BasketLine without specifying Part
.WithRequired(x => x.Service); // cannot save BasketLine without using Service
}
相关问题：
Configure One-to-One Relationships in EF Code First
我正在尝试开发一个汽车服务预订应用程序，它允许人们既可以预订汽车进行服务，也可以购买一些零件，这不是必需的，但我收到一个错误，内容如下如下：
SqlException: The INSERT statement conflicted with the FOREIGN KEY constraint "FK_dbo.BasketLines_dbo.Parts_PartID". The conflict occurred in database "aspnet-Noir-20190224082924", table "dbo.Parts", column 'PartId'. The statement has been terminated.
我的类如下：
部分
public class Part
{
[Key]
public int PartId { get; set; }
public string Name { get; set; }
public string Description { get; set; }
public byte[] ImageFile { get; set; }
public string ImageFilePath { get; set; }
public decimal Price { get; set; }
public virtual ICollection<ServicePartMapping>
ServicePartMappings { get; set;}
}
服务
public class Service
{
public int ServiceId { get; set; }
public string Name { get; set; }
public string Type { get; set; }
public decimal Price { get; set; }
public ICollection<Part> Parts { get; set; }
}
ServicePartMapping
public class ServicePartMapping
{
public int ServicePartMappingID { get; set; }
public int PartNumber { get; set; }
public int? ServiceId { get; set; }
public int? ServicePartId { get; set; }
public virtual Service Service { get; set; }
public virtual ServicePart ServicePart { get;
set; }
}
购物篮
public class Basket
{
public int Id { get; set; }
private string BasketID { get; set; }
private const string BasketSessionKey =
"BasketID";
private ApplicationDbContext db = new
ApplicationDbContext();
private string GetBasketID()
{
if
(HttpContext.Current.Session[BasketSessionKey]
== null)
{
if
(!string.IsNullOrWhiteSpace
(HttpContext.Current
.User.Identity.Name))
{
HttpContext.Current
.Session[BasketSessionKey] =
HttpContext.Current
.User.Identity.Name;
}
else
{
Guid tempBasketID = Guid.NewGuid()
HttpContext.Current
.Session[BasketSessionKey]
= tempBasketID.ToString();
}
}
return
HttpContext.Current
.Session[BasketSessionKey].ToString();
}
public static Basket GetBasket()
{
Basket basket = new Basket();
basket.BasketID = basket.GetBasketID();
return basket;
}
public void AddServiceToBasket(int serviceID,
int quantity)
{
var basketLine =
db.BasketLines.FirstOrDefault(b =>
b.BasketID == BasketID && b.ServiceID
== serviceID);
if (basketLine == null)
{
basketLine = new BasketLine
{
ServiceID = serviceID,
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
}
else
{
basketLine.Quantity += quantity;
}
db.SaveChanges();
}
public void AddPartToBasket(int partID, int
quantity)
{
var basketLine =
db.BasketLines.FirstOrDefault(b =>
b.BasketID == BasketID && b.PartId
== partID);
if (basketLine == null)
{
basketLine = new BasketLine
{
PartId = partID,
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
}
else
{
basketLine.Quantity += quantity;
}
db.SaveChanges();
}
public void RemoveLine(int ID)
{
var basketLine = db.BasketLines.FirstOrDefault(b => b.BasketID == BasketID && b.ServiceID
== ID || b.PartId == ID);
if (basketLine != null)
{
db.BasketLines.Remove(basketLine);
}
db.SaveChanges();
}
public void UpdateBasket(List<BasketLine> lines)
{
foreach (var line in lines)
{
var basketLine = db.BasketLines.FirstOrDefault(b => b.BasketID == BasketID &&
b.ServiceID == line.ServiceID);
if (basketLine != null)
{
if (line.Quantity == 0)
{
RemoveLine(line.ServiceID);
}
else
{
basketLine.Quantity = line.Quantity;
}
}
}
db.SaveChanges();
}
public void EmptyBasket()
{
var basketLines = db.BasketLines.Where(b => b.BasketID == BasketID);
foreach (var basketLine in basketLines)
{
db.BasketLines.Remove(basketLine);
}
db.SaveChanges();
}
public List<BasketLine> GetBasketLines()
{
return db.BasketLines.Where(b => b.BasketID == BasketID).ToList();
}
public decimal GetTotalCost()
{
decimal basketTotal = decimal.Zero;
decimal serviceTotal = decimal.Zero;
decimal partTotal = decimal.Zero;
if (GetBasketLines().Count > 0)
{
serviceTotal = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Service.Price
* b.Quantity);
partTotal = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Part.Price
* b.Quantity);
basketTotal = serviceTotal + partTotal;
}
return basketTotal;
}
public int GetNumberOfItems()
{
int numberOfItems = 0;
if (GetBasketLines().Count > 0)
{
numberOfItems = db.BasketLines.Where(b => b.BasketID == BasketID).Sum(b => b.Quantity);
}
return numberOfItems;
}
public void MigrateBasket(string userName)
{
//find the current basket and store it in memory using ToList()
var basket = db.BasketLines.Where(b => b.BasketID == BasketID).ToList();
//find if the user already has a basket or not and store it in memory using ToList()
var usersBasket = db.BasketLines.Where(b => b.BasketID == userName).ToList();
//if the user has a basket then add the current items to it
if (usersBasket != null)
{
//set the basketID to the username
string prevID = BasketID;
BasketID = userName;
//add the lines in anonymous basket to the user's basket
foreach (var line in basket)
{
AddServiceToBasket(line.ServiceID, line.Quantity);
AddPartToBasket(line.PartId, line.Quantity);
}
//delete the lines in the anonymous basket from the database
BasketID = prevID;
EmptyBasket();
}
else
{
//if the user does not have a basket then just migrate this one
foreach (var basketLine in basket)
{
basketLine.BasketID = userName;
}
db.SaveChanges();
}
HttpContext.Current.Session[BasketSessionKey] = userName;
}
public decimal CreateOrderLines(int orderID)
{
decimal orderTotal = 0;
var basketLines = GetBasketLines();
foreach (var item in basketLines)
{
BillLine BillLine = new BillLine
{
Service = item.Service,
ServiceID = item.ServiceID,
ServiceName = item.Service.Name,
Quantity = item.Quantity,
ServicePrice = item.Service.Price,
BillID = orderID
};
orderTotal += (item.Quantity * item.Service.Price);
db.BillLines.Add(BillLine);
}
db.SaveChanges();
EmptyBasket();
return orderTotal;
}
}
篮筐线
public class BasketLine
{
public int ID { get; set; }
public string BasketID { get; set; }
public int ServiceID { get; set; }
public int PartId { get; set; }
[Range(0, 50, ErrorMessage = "Please enter a quantity between 0 and 50")]
public int Quantity { get; set; }
public DateTime DateCreated { get; set; }
public virtual Service Service { get; set; }
public virtual Part Part { get; set; }
}
假设使用了 EF Code First，异常消息表明您在 BasketLines table 中使用了外键约束，它引用了 [=15] 中的 PartId 主键列=] table，而您正试图在 BasketLines.PartId 列中插入一个值，而该值在 Parts table 中不存在，在此语句中：
basketLine = new BasketLine
{
PartId = partID, // this assignment is the problem source
BasketID = BasketID,
Quantity = quantity,
DateCreated = DateTime.Now
};
db.BasketLines.Add(basketLine);
根据检查，您试图在 Service、Part 和 BasketLine 实体之间建立关系，因此我建议为 [=22 添加 ForeignKeyAttribute =] 和 PartId 属性 在 BasketLine 实体中：
public class BasketLine
{
public int ID { get; set; }
public string BasketID { get; set; }
[ForeignKey("Service")]
public int ServiceID { get; set; }
[ForeignKey("Part")]
public int PartId { get; set; }
[Range(0, 50, ErrorMessage = "Please enter a quantity between 0 and 50")]
public int Quantity { get; set; }
public DateTime DateCreated { get; set; }
public virtual Service Service { get; set; }
public virtual Part Part { get; set; }
}
此外，由于声明 BasketLine 需要 Service 和可选的 Part，您也可以尝试像这样修改 DbContext 中的 OnModelCreating() 方法:
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
modelBuilder.Entity<BasketLine>()
.HasOptional(x => x.Part) // can save BasketLine without specifying Part
.WithRequired(x => x.Service); // cannot save BasketLine without using Service
}
相关问题：
Configure One-to-One Relationships in EF Code First