-- SELECT 查询

-- 查询表中所

SELECT *FROM student;

-- 查询单列

SELECT sname FROM student;

-- 查询多列

SELECT sname,age FROM student;

-- 给列名设置别名  as  可以省略不写

SELECT sname AS 姓名,age AS 芳龄 FROM student;

-- 条件查询  where 查询姓名为张三的信息

SELECT *FROM student WHERE sname = '张三';

-- 查询性别为男的信息

SELECT *FROM student WHERE sex = '男';

-- 多条件查询   

-- 查询性别为男而且姓名为亚瑟的信息  and

SELECT *FROM student WHERE sex = '男'AND sname = '亚瑟';

-- 查询性别为男或者姓名为李四的信息or

SELECT *FROM student WHERE sex = '男'OR sname = '李四';

-- > < >= <= != <>

-- 查询年龄在17-36岁之间的信息

SELECT *FROM student WHERE age >= 17 AND age <= 36;

-- 范围查询 between... and ...

SELECT *FROM student WHERE age BETWEEN 17 AND 23 OR sex = '女';

-- 性别不为男的信息

SELECT *FROM student WHERE sex<>'男';

SELECT *FROM student WHERE sname > '张三';