mysql基本查询语句

-- 使用星号查询表中的全部内容
SELECT * FROM tb_students_info;

-- 使用字段名查询表中全部字段
SELECT id,name,dept_id,age,sex,height,login_date
FROM tb_students_info;

-- 查询表中指定的字段
SELECT name FROM tb_students_info;

-- 去除结果中的重复行
SELECT  DISTINCT age
FROM tb_students_info;

-- 给表设置别名
SELECT stu.name,stu.height
FROM tb_students_info AS stu;

-- 给列设置别名
SELECT name AS student_name,
age AS student_age
FROM tb_students_info;

-- 指定查询结果的行数
SELECT * FROM tb_students_info LIMIT 4;

-- 根据位置偏移量指定查询行数
SELECT * FROM tb_students_info LIMIT 3,5;

-- 对查询结果进行排序
SELECT * FROM tb_students_info ORDER BY height;

-- 对查询结果的多列进行排序
SELECT name,height
FROM tb_students_info
ORDER BY height,name;

-- 单一条件的查询语句
SELECT name,height
FROM tb_students_info
WHERE height=170;

-- 多条件的查询语句
SELECT * FROM tb_students_info
WHERE age>21 AND height>=175;

-- 使用百分号通配符进行模糊查询
SELECT name FROM tb_students_info
WHERE name LIKE 'T%';

-- 使用下划线通配符进行模糊查询
SELECT name FROM tb_students_info
WHERE name LIKE '____y';

-- 使用比较运算符设置日期条件
SELECT * FROM tb_students_info
WHERE login_date<'2016-01-01';

-- 使用BETWEEN AND运算符设置日期条件
SELECT * FROM tb_students_info
WHERE login_date
BETWEEN '2015-10-01'
AND '2016-05-01';