从ERD创建SQL表，实现所有约束

Question

This is the ERD digram from which I'm to write and SQL query for .

Answer 1

这是给Oracle的。您可以类似地创建PRODUCT表，而无需FOREIGN KEY：

  CREATE TABLE Orders (
        OrderID int NOT NULL,
        OrderDate date,
        ProductID int,
        PRIMARY KEY (OrderID),
        CONSTRAINT FK_PersonOrder FOREIGN KEY (ProductID)
        REFERENCES PRODUCT(ProductID)
    );

Answer 2

Sql Server

产品表

CREATE TABLE product 
  ( 
     productid   INT PRIMARY KEY IDENTITY(1, 1), 
     productname VARCHAR(50), 
     unitprice   NUMERIC(17, 2) 
  ) 

订单表

CREATE TABLE orders 
  ( 
     orderid     INT PRIMARY KEY IDENTITY(1, 1), 
     productname VARCHAR(50), 
     productid   INT, 
     FOREIGN KEY (productid) REFERENCES product(productid) 
  )