mysql必知必会

   day1
 1 mac mysql 安装
 2 for bash：
 3 alias mysql=/usr/local/mysql/bin/mysql
 4 alias mysqladmin=/usr/local/mysql/bin/mysqladmin
 5 
 6 登录 mysql -u root - p
 7 改密码 mysqladmin -u root -p password
 8 USE database;
 9 SHOW DATABASES;
10 SHOW TABLES;
11 SHOW COLUMNS FROM table_name;(= DESCRIBE table_name;)
12 SHOW STATUS;
13 SHOW GRANTS;
14 SHOW ERRORS; SHOW WARNINGS;
15 
16 SELECT column_name FROM table_name;
17 SELECT column_name1, column_name2, column_name3 FROM table_name;
18 SELECT * FROM table_name;
19 SELECT DISTINCT column_name FROM table_name;
20 SELECT column_name FROM table_name LIMIT 5;(前5行，即0-4行)
21 SELECT column_name FROM table_name LIMIT 5,6;(第五行开始的6行）=
22 SELECT column_name FROM table_name LIMIT 6 OFFSET 5;
23 SELECT table_name.column_name FROM table_name;
24 SELECT table_name.column_name FROM database_name.table_name;
25 SELECT column_name FROM table_name ORDER BY column_name;
26 SELECT column_name1, column_name2, column_name3 FROM table_name ORDER BY column_name1, column_name2;
27 SELECT column_name1, column_name2, column_name3 FROM table_name ORDER BY column_name1 DESC, column_name2;(column_name1降序排列 ASC 升序，默认的)