mysql常用操作（持续更新）_mysql varchar unixtime-优快云博客

本文介绍了一系列MySQL实用操作，包括下载表数据、设置启动脚本、查询系统时间、设置时区、输出表信息、创建和修改表结构等核心技能。

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1.下载表

mysql -h 127.0.0.1 -P 3306 -u root -p123456 data_yjx_normal -e "select * from task;" > task.txt

2.设置sql常用启动脚本

[jingsia@localhost ~]$ cat bin/sql 
mysql -h 127.0.0.1 -P 3306 -u jingsia -p123456

3.查询系统时间方法

mysql>  select current_date as Systemtime;
+------------+
| Systemtime |
+------------+
| 2017-01-22 |
+------------+

mysql> select now();
+---------------------+
| now()               |
+---------------------+
| 2017-01-22 14:37:35 |
+---------------------+

mysql> select sysdate();
+---------------------+
| sysdate()           |
+---------------------+
| 2017-01-22 14:38:44 |
+---------------------+

4.设置时间东八区

set time_zone = '+8:00'

5.查看时区

mysql> show variables like "%time_zone%";
+------------------+--------+
| Variable_name    | Value  |
+------------------+--------+
| system_time_zone | PST    |
| time_zone        | +08:00 |
+------------------+--------+

vim /etc/my.cnf
在mysqld段里添加如下字段
default-time_zoen = '+8:00'

6.输出表具体信息

show full fields from 表名称;

7.创建表

DROP TABLE IF EXISTS `gov_exploit`;                                                                                       
CREATE TABLE `gov_exploit`(
    `id` tinyint(3) unsigned NOT NULL DEFAULT '0',
    `type` tinyint(3) unsigned NOT NULL DEFAULT '0',
    `openLevel` tinyint(3) unsigned NOT NULL DEFAULT '0',
    `growLevel` varchar(255) NOT NULL,
    `bonus` varchar(255) NOT NULL,
    `cost` varchar(255) NOT NULL,
    PRIMARY KEY(`id`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8;

8.增删改查表

alter TABLE `equip` add column `hp` int(10) NOT NULL DEFAULT '0' after `id`;                                              
alter table `equip` change  column `konck` `knock` int(10);

alter table `equip` drop KEY id;

alter table `equip` drop column hp;

select * from `equip`;

查看列：desc 表名;
修改表名：alter table t_book rename to bbb;
添加列：alter table 表名 add column 列名 varchar(30);
删除列：alter table 表名 drop column 列名;
修改列名： alter table bbb change nnnnn hh int;
修改列属性：alter table t_book modify name varchar(22);

9.时间戳函数unix_timestamp和from_unixtime

->将时间转换为时间戳，没参数则当前时间

mysql> select unix_timestamp();
+------------------+
| unix_timestamp() |
+------------------+
|       1485070742 |
+------------------+

->将时间戳转化为date

mysql> select from_unixtime(1484323200);
+---------------------------+
| from_unixtime(1484323200) |
+---------------------------+
| 2017-01-14 00:00:00       |
+---------------------------+