SELECT DISTINCT Company FROM Orders
SELECT * FROM Persons WHERE City='Beijing'
SELECT * FROM Persons WHERE firstname='Thomas' OR lastname='Carter'
SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber
INSERT INTO Persons VALUES ('Gates', 'Bill', 'Xuanwumen 10', 'Beijing')UPDATE Person SET FirstName = 'Fred' WHERE LastName = 'Wilson'
DELETE FROM Person WHERE LastName = 'Wilson'
SELECT TOP 2 * FROM Persons
SELECT * FROM Persons
WHERE City LIKE '%lon%'
SELECT * FROM Persons
WHERE FirstName LIKE '_eorge'
SELECT * FROM Persons
WHERE LastName IN ('Adams','Carter')SELECT * FROM Persons
WHERE LastName
BETWEEN 'Adams' AND 'Carter'
SELECT po.OrderID, p.LastName, p.FirstName
FROM Persons AS p, Product_Orders AS po
WHERE p.LastName='Adams' AND p.FirstName='John'
SELECT Product_Orders.OrderID, Persons.LastName, Persons.FirstName
FROM Persons, Product_Orders
WHERE Persons.LastName='Adams' AND Persons.FirstName='John'
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons, Orders
WHERE Persons.Id_P = Orders.Id_P
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons
INNER JOIN Orders
ON Persons.Id_P=Orders.Id_P
ORDER BY Persons.LastName
SELECT Persons.LastName, Persons.FirstName, Orders.OrderNo
FROM Persons
LEFT JOIN Orders
ON Persons.Id_P=Orders.Id_P
ORDER BY Persons.LastName
SELECT E_Name FROM Employees_China
UNION
SELECT E_Name FROM Employees_USA
SELECT INTO 语句从一个表中选取数据，然后把数据插入另一个表中
SELECT LastName,FirstName
INTO Persons_backup
FROM Persons
CREATE DATABASE database_name
CREATE TABLE Persons
(
Id_P int,
LastName varchar(255),
FirstName varchar(255),
Address varchar(255),
City varchar(255)
)
CREATE INDEX PersonIndex
ON Person (LastName)
SELECT Customer,SUM(OrderPrice) FROM Orders
GROUP BY Customer
SELECT Customer,SUM(OrderPrice) FROM Orders
GROUP BY Customer
HAVING SUM(OrderPrice)<2000
SELECT Customer FROM Orders
WHERE OrderPrice>(SELECT AVG(OrderPrice) FROM Orders)
