mysql learning note

1 login: mysql -u root  -p
   
2 exit : quit


3 step of operation to mysql:
  create a database      :    mysql> create database lwjbase;
  then checked if success:    mysql>show databases;
  then changed to lwjbase:    mysql> use lwjbase;
  then create table      :    mysql>create table worker (nid INT UNIQUE,name VARCHAR(20),address VARCHAR(200),salary float,level int);
  then insert data to    :    mysql>insert into worker values(100,'tom','beijing',2000.0,0);
  then lookup data       :    mysql>select * from worker;
  then delete data       :    mysql>delete  from worker where nid=100;
  then updata data       :    mysql>update worker set level=2,salary=6999.0 where nid=100;
  then delete table      :    mysql>drop table lwjbase;
  then delete datebase   :    mysql>drop datebase lwjbase;

4:  three method to insert note
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