SQL数据库外键问题（INSERT语句与外键约束“ FK__Orders__Employee__0F624AF8”冲突

Question

任何帮助将不胜感激，因为这是我的第一个sql项目。我以正确的顺序创建了表，但是当我尝试将数据插入到orders表中时会引发错误。 插入订单时，请检查最后一张桌子。 谢谢

CREATE TABLE Suppliers (
SupplierId int IDENTITY (1,1) NOT NULL,
CompanyName nvarchar(50) NOT NULL,
ContactName nvarchar(50) NOT NULL,
City  nvarchar(20) NOT NULL,
Phone nvarchar(20) NOT NULL,
Homepage ntext NOT NULL
CONSTRAINT PK_Suppliers PRIMARY KEY (SupplierId)

 )  
  INSERT INTO Suppliers
(CompanyName,ContactName,City,Phone,Homepage)
VALUES
('GardenWorld','JimL','Dublin','085-1588902','Gardenworld.ie'),
('HomeFixLtd','AnneG','Cork','087-1584402','HomeFix.ie'),
('PleasureDome','PaulH','Dublin','086-3248902','PleasureDome.ie'),
('BuildBase','GarthN','Belfast','004485-1588902','BuildBase.co.uk'),
('RenewTools','HarryH','Galway','087-4567835','RenewTools.ie')

CREATE TABLE Products
(
  ProductID int IDENTITY(1,1) NOT NULL PRIMARY KEY,
  ProductName nvarchar(50) NOT NULL,
  SupplierId int NOT NULL,
  Category   nvarchar(50) NOT NULL,
 UnitPrice money NOT NULL,
 UnitsInStock smallint NOT NULL,
  UnitsOnOrder smallint NOT NULL,
  ReOrderLevel smallint NOT NULL,
 FOREIGN KEY (SupplierId) REFERENCES Suppliers (SupplierId)

)
 INSERT INTO dbo.Products
    (ProductName,SupplierId,Category,UnitPrice,UnitsInStock,UnitsOnOrder,ReOrderLeve   l)
VALUES

('Fork Handles','1','Garden','10.00','125','0','25'),
 ('Hammer','2','DIY','3.00','129','0','40'),
('Bucket','4', 'Garden','5.00','25','30','30'),
('Solar Battery','2','DIY','15.00','112','0','35'), 
('Lawnmower','1','Garden','150.00','24','8','25'),
('Kitchen Sink','4','DIY','80.00','115','0','30'),
('Cement Bag','4','DIY','10.00','130','0','25'),
('Compost Bag','1','Garden','5.00','135','0','20'),
('Chainsaw','1','Garden','100.00','11','15','15'),
('Sun Lounger','3','Leisure','30.00','4','30','10'),
('Light Bulb','4','DIY','5.00','17','50','35'),
('Paint Set','5','DIY','10.00','25','0','30'),
('Ladder','2','DIY','28.00','5','20','10'),
 ('Wheel Barrow','1','Garden','50.00','125','0','24'),
 ('Dinghy','3','Leisure','100.00','4','20','10')

    CREATE TABLE Customers(
CustomerId int IDENTITY (1,1) NOT NULL,
FirstName nvarchar(50) NOT NULL,
LastName nvarchar(50) NOT NULL,
CompanyName nvarchar(40) NOT NULL,
City nvarchar(20) NOT NULL,
Country nvarchar(20) NOT NULL,
Phone nvarchar(25) NOT NULL,
Email nvarchar(25) NOT NULL
   CONSTRAINT PK_Customers PRIMARY KEY (CustomerId))

  INSERT INTO Customers

   (FirstName,LastName,CompanyName,City,Country,Phone,Email)

  VALUES

  ('Edgar','Codd','n/a','Galway','Eire','085-1233456','ec@yahoo.com'),
  ('John','Byrne','JB Landscapes','Limerick','Eire','086-2347656','jc@gmail.com'),
  ('Jane','Ryan','n/a','Dublin','Eire','087-1569846','jr@live.com'),
  ('Bill','Bates','n/a','Cork','Eire','085-1245356','bb@yahoo.com'),
  ('Ridley','Scott','RS Carpentry','Galway','Eire','085-8933456','rs@yahoo.com'),
 ('Anne','Smith','n/a','Dublin','Eire','087-7988456','as@yahoo.com'),
  ('Paul','Jones','PJ Plumbers','Belfast','UK','085-          6723456','PJ@yahoo.com'),
  ('James','Ryan','JR Bros','London','UK','085-6723456','jr@yahoo.com'),
 ('Jim','Reilly','n/a','Cork','Eire','085-6888456','jj@yahoo.com'),
 ('Emily','Rigby','n/a','London','UK','085-6778946','er@gmail.com')

  CREATE TABLE Employees(
EmployeeId int IDENTITY (1,1) PRIMARY KEY NOT NULL,
FirstName nvarchar(50) NOT NULL,
LastName nvarchar(50) NOT NULL,
Department nvarchar(20) NOT NULL,
City nvarchar(20) NOT NULL,
Age smallint NOT NULL,
Salary int NOT NULL,
Commission_Pct decimal(2,2) NOT NULL
  )

   INSERT INTO Employees
   (FirstName,LastName,Department,City,Age,Salary,Commission_Pct)
  VALUES
  ('John','Cusack','Garden','Dublin','44','30000','0.00'),
  ('Todd','Louiso','DIY','Dublin','32','25000','0.05'),
   ('Jack','Black','Garden','Galway','22','22000','0.20'),
   ('Joan','Barrett','DIY','Dublin', '34','30000','0.05'),
   ('Barry','Behan','DIY', 'Belfast','55','35000','0.00')


 CREATE TABLE Orders
 (
  OrderID int IDENTITY(1,1)NOT NULL PRIMARY KEY,
  CustomerID int NOT NULL,
  ProductID int NOT NULL,
  UnitPrice money NOT NULL,
  Quantity smallint NOT NULL,   
  EmployeeID int NOT NULL,
  OrderDate date NOT NULL,
  DispatchDate date NOT NULL,  
  FOREIGN KEY (ProductID) REFERENCES Products(ProductID),
  FOREIGN KEY(CustomerID) REFERENCES Customers(CustomerId),
  FOREIGN KEY(EmployeeID) REFERENCES Employees(EmployeeId)
 )

这是Orders表上的INSERT问题

  INSERT INTO Orders
(CustomerID,ProductID,UnitPrice,Quantity,EmployeeID,OrderDate,DispatchDate)
 VALUES
('2','1','3.00','5','3','2017-05-19','2017-05-23'),
('3','4','15.00','2','4','2017-05-10','2017-05-19'),
('7','3','5.00','10','4','2017-05-14','2017-05-17'),
 ('5','9','100.00','3','8','2017-05-05','2017-05-11'),
('6','10','30.00','4','9','2017-05-05','2017-05-09'),
('1','8','5.00','10','4','2017-05-05','2017-05-07'),
('3','11','5.00','15','5','2017-05-11','2017-05-17'),
('7','13','28.00','3','2','2017-05-15','2017-05-19'),
('4','6','80.00','10','5','2017-05-15','2017-05-19'),
('10','5','150.00','2','1','2017-05-15','2017-05-18')

这将产生以下错误。

The INSERT statement conflicted with the FOREIGN KEY constraint "FK__Orders__Employee__0F624AF8". The conflict occurred in database "Billy Joes Hardware/Assignment", table "dbo.Employees", column 'EmployeeId'. The statement has been terminated.

Answer 1

看来您实际上有2行会违反约束。

('5','9','100.00','3','8','2017-05-05','2017-05-11'),
('6','10','30.00','4','9','2017-05-05','2017-05-09')

如果运行SELECT EmployeeId FROM Employees ，则会得到此信息。

EmployeeId
-----------
1
2
3
4
5

或者，您可以SELECT MAX(EmployeeId) FROM Employees运行SELECT MAX(EmployeeId) FROM Employees并得到5作为结果。

您收到此错误的原因是，插入的第四行的EmployeeId为8 ，插入的第五行的EmployeeId为9 。 由于Employees表中只有5行，因此8和9是无效的EmployeeId 。 您需要更改插入中的EmployeeId或将更多行插入到Employees表中

我创建了这张表的图表。 这将显示您的外键关系。 这应该可以帮助您了解另一个表中需要一个表中的有效值。

Answer 2

在要插入EmployeeId的表Orders中，检查第5个值为9：

('6','10','30.00','4','9','2017-05-05','2017-05-09'),

而且您只在Employees表上插入了5条记录，我非常确定您的最大id为5，因为在Employees上不存在，所以不能对Orders表使用Employeeid = 9。 并且您对Orders表有以下限制： FOREIGN KEY(EmployeeID) REFERENCES Employees(EmployeeId) 。

解

在插入“订单”之前，请先检查“员工”表上可用的“ EmployeesId”。 要检查这一点，请使用SELECT * FROM EMPLOYEES

（不推荐）如果要无限制地插入任何EmployeesId值，则应删除此行： FOREIGN KEY(EmployeeID) REFERENCES Employees(EmployeeId)

希望这可以帮助