建立数据库 3个表格及各自的属性 和join

CREATE TABLE Customers(cID INT PRIMARY KEY, cName VARCHAR(99));
CREATE TABLE Orders(Oid INT PRIMARY KEY,cID INT,CONSTRAINT FK_CID FOREIGN KEY (cID) REFERENCES Customers(cID))
CREATE TABLE OrderDetails(Odid INT PRIMARY KEY,Oid INT,CONSTRAINT FK_Oid FOREIGN KEY (Oid) REFERENCES Orders(Oid))
SELECT * FROM Customers c JOIN Orders O ON C.cID=O.cID
JOIN OrderDetails od ON o.Oid = od.Odid