SQList使用详解.txt

//DISTINCT 关键词 ,查询排除重复值 a,b,c,b -> a,b,c 
SELECT DISTINCT Company FROM Orders

//使用 WHERE 子句
//文本类型值要用''号括起来
SELECT * FROM Persons WHERE FirstName='Bush'
//数字类型不要
SELECT * FROM Persons WHERE Year>1965

//AND 运算符实例
SELECT * FROM Persons WHEREFirstName='Thomas' AND LastName='Carter'
//OR 运算符实例
SELECT * FROM Persons WHEREfirstname='Thomas' OR lastname='Carter'
结合 AND 和 OR 运算符
SELECT * FROM Persons WHERE (FirstName='Thomas' OR FirstName='William') AND LastName='Carter'

//ORDER BY 语句用于对结果集进行排序。
SELECT Company, OrderNumber FROM Orders ORDER BY Company
//双列查询,先用Company排序,再用OrderNumber排,默认升序(从A到Z,0到9)
SELECT Company, OrderNumber FROM Orders ORDER BY Company, OrderNumber
//降序关键字 DESC (从Z到A,9到0)
SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC
//双列查询,一列降序，一列升序
SELECT Company, OrderNumber FROM Orders ORDER BY Company DESC, OrderNumber ASC

//INSERT INTO 语句 
//插入新的行,所有列
INSERT INTO Persons VALUES ('Gates', 'Bill','Xuanwumen 10', 'Beijing')
//在指定的列中插入数据
INSERT INTO Persons (LastName, Address)VALUES ('Wilson', 'Champs-Elysees')