MySQL操作汇总

CREATE TABLE goods2 (
  NAME VARCHAR(10),
  price DOUBLE,
  sales_volume INT,
  produced_date DATE,
  category VARCHAR(20)
);

INSERT INTO goods2 VALUES 
('华为P40',5999,1000,'2020-08-20','手机'),
('小米11',4999,5000,'2020-12-28','手机'),
('红米K30',2999,22000,'2020-03-11','手机'),
('糯米',8.99,200,'2016-06-08','食物'),
('米糊',7.99,30,'2013-11-22','食物'),
('iPhone 12',6799,12000,'2020-10-28','手机'),
('DELL 7590',8799,300,'2019-06-18','电脑'),
('立白洗衣粉',12.9,39000,'2018-02-13','日用品'),
('立白洗衣粉',12.9,39000,'2018-02-13','日用品'),
(NULL,88,666,NULL,NULL),
('联想电脑',8799,700,'2017-03-13','电脑'),
('惠普电脑',8799,50,'2008-12-13','电脑');

登录格式1：登录本机的MySQL
    mysql -u用户名 -p密码
    示例:mysql -uroot -proot

登录格式2：登录远程的MySQL
    mysql -u用户名 -p密码 –h远程主机ip
    示例:mysql -uroot -proot -h127.0.0.1

退出MySQL
    exit 或 quit

MySQL常见数据类型

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 count(*):分组里面所有数量