mysql查幫助手冊的技巧：help 你的命令；比如 help create;
>>顯示mysql中用戶：select host,user from mysql.user;
>>>創建用戶：mysql> create user 'zhangpeng'@'%' identified by 'oradt!@#&*(';
>>授權某個用戶擁有某個數據庫的任何權限：
GRANT ALL PRIVILEGES ON stock_info.* TO 'test'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;
創建數據庫： mysql> create database stock_info default charset utf8 collate utf8_general_ci;
>>> 查看用戶權限(顯示用戶權限): show grants from 用戶名; //show grants; 顯示當前自己的權限
修改用戶密碼-> 首先進入命令行下, 以root用戶登錄，命令：mysql -uroot -p 回車 輸入密碼再回車;
USER mysql;
UPADTE user set password=password('root') where user='root';
mysql> FLUSH PRIVILEGES;//記得要這句話
>>> mysql優化表(回收表占用的閑置數據庫空間),代碼如何：
REPAIR TABLE `table_name` 修復表
OPTIMIZE TABLE `table_name` 優化表
1.備份表結構(加上-d只備份表結構，不加此參數表結構、數據都備份)：
C:\Program Files\MySQL\MySQL Server 5.6\bin>mysqldump -hlocalhost -P3308 -uroot
-p -d stock_info>F:/stock_info.sql
Enter password: ******
備份單個表的數據(表必須不存在)：
create table st_pool_bak as SELECT id,code FROM `st_pool` ;
mysql 查看數據庫中所有表的記錄數(總記錄數)use information_schema;
select table_name,table_rows from tables
where TABLE_SCHEMA = 'imora_scan'
order by table_rows desc;
MySQL LIMIT分頁優化： SELECT * FROM `api_statistic` as apis
INNER JOIN (select id from api_statistic as ap2 limit 1410000,10 ) as c using(id);
把字段合並成一條記錄返回: select GROUP_CONCAT(COLUMN_NAME) from information_schema.COLUMNS where table_name = 'biz_employee_cards';
select COLUMN_NAME from information_schema.COLUMNS where table_name = 'your_table_name' and table_schema = 'your_db_name';
GROUP_CONCAT ( url SEPARATOR " @ " )