USE xu;
CREATE TABLE ma(
id INT PRIMARY KEY AUTO_INCREMENT,
sname VARCHAR(500),
age INT,
sex VARCHAR(500),
gongzi DOUBLE
);
INSERT INTO ma VALUES( 1,'一一',19,'男',1100 );
INSERT INTO ma VALUES( 2,'二二',19,'女',1200);
INSERT INTO ma VALUES( 3,'三三',21,'男',1300);
INSERT INTO ma VALUES( 4,'四四',18,'女',1400 );
INSERT INTO ma VALUES( 5,'五五',15,'男',1500 );
INSERT INTO ma VALUES( 6,'六六',19,'女',1600 );
INSERT INTO ma VALUES( 7,'七七',22,'男',1700 );
INSERT INTO ma VALUES( 8,'八八',16,'女',1800 );
INSERT INTO ma VALUES( 9,'九九',17,'男',1900 );
INSERT INTO ma VALUES(10,'十十',20,'女',2000 );
INSERT INTO ma VALUES( 11,'五五',15,'男',1500 );
INSERT INTO ma VALUES( 12,'六六',19,'女',1600 );
INSERT INTO ma VALUES( 13,'七七七',22,'男',1700 );
SELECT id FROM ma;
SELECT sname FROM ma;
SELECT DISTINCT sname FROM ma;/*去掉 sname 重复的那一行*/
SELECT gongzi AS gz FROM ma; /*别名 关键字as*/
SELECT sname,gongzi+1000 FROM ma;/*对列进行运算*/
SELECT *FROM ma WHERE gongzi>=1500;/*筛选出大于等于1500*/
/*取值在1200到1800之间 between 。。。and*/
SELECT *FROM ma WHERE gongzi BETWEEN 1200 AND 1800;
/*模糊查询*/
SELECT *FROM ma WHERE sname LIKE '四四';
SELECT * FROM ma WHERE sex LIKE'男';
SELECT * FROM ma WHERE sname LIKE'___';/*下划线有几个查找几个字的哪一行*/
/*排序查询*/
SELECT * FROM ma ORDER BY gongzi ASC;/*asc 升序*/
SELECT * FROM ma ORDER BY gongzi DESC;/*desc 降序*/