MySQL一些命令

hailai

1:使用SHOW语句找出在服务器上当前存在什么数据库：
mysql> SHOW DATABASES;
2:2、创建一个数据库MYSQLDATA
mysql> CREATE DATABASE MYSQLDATA;
drop database mydb;

3:选择你所创建的数据库
mysql> USE MYSQLDATA; //(按回车键出现Database changed 时说明操作成功！)
4:查看现在的数据库中存在什么表
mysql> SHOW TABLES;
5:创建一个数据库表
mysql> CREATE TABLE MYTABLE (name VARCHAR(20), sex CHAR(1));
6:显示表的结构：
mysql> DESCRIBE MYTABLE;
7:往表中加入记录
mysql> insert into MYTABLE values (”hyq”,”M”);
8:用文本方式将数据装入数据库表中（例如D:/mysql.txt）
mysql> LOAD DATA LOCAL INFILE “D:/mysql.txt” INTO TABLE MYTABLE;
9:导入.sql文件命令（例如D:/mysql.sql）
mysql>use database;
mysql>source d:/mysql.sql;
导入数据可能需要在未登录mysql下
linux> mysql -usrs -padmin --host=10.10.0.1 -D srstest < /home/test.sql
10:删除表
mysql>drop TABLE MYTABLE;
11:清空表
mysql>delete from MYTABLE;
12:更新表中数据
mysql>update MYTABLE set sex=”f” where name=’hyq’;
13:修改表
mysql>ALTER TABLE `orgs` ADD COLUMN `COUNTRY`  int(11) NULL AFTER `COUNTRY_ID`;
mysql>ALTER TABLE `orgs` DROP COLUMN `COUNTRY`;

14:库对库传数据：
mysql>mysqldump -h '10.10.2.120' -usrsadmin -padmin123 --opt --compress fromdbname --skip-lock-tables | mysql -h '10.10.2.231' -usrs -padmin123 todbname //第一个-h为源数据库fromdbname为数据库名


mysql> show variables like '%timeout%';
mysql> show variables like '%max_allowed%';
mysql> set wait_timeout = 36000;
mysql> show variables like '%character%';
mysql> set character_set_client = utf8;
mysql> UPDATE action SET `ORG` = CONVERT(CAST(CONVERT( `ORG` USING latin1) AS BINARY) USING utf8); #解决双重编码问题
http://stackoverflow.com/questio ... s-in-an-utf-8-table
linux> mysql --help | grep my.cnf

linux> service mysqld restart
linux> vi /etc/mysql/my.cnf  // >cat /etc/my.cnf
  在[client]和[mysqld]下面添加 default-character-set=utf8

对于mysql编码的处理。MySQL默认latin1编码，建表时候用的utf8，导致中午或其他语言乱码，导出数据直接查看也是乱码。
可先通过.sql文件导入导出

mysql -uadmin -padmin --host=10.10.250.100 -D table_from_uat < ./table_from_qa_20131217_01.sql
set names utf8;
select * from table1;//可正常显示中文，如果有中文乱码可能需要二次转码
UPDATE t_label SET `VALUE` = CONVERT(CAST(CONVERT(`VALUE` USING latin1) AS BINARY) USING utf8);


SELECT OPEN_DATE,CLOSED_DATE,PENDING_CONFIRMATION_DATE,
(IFNULL(IFNULL(CLOSED_DATE,PENDING_CONFIRMATION_DATE),NOW()))AS aged,
TIMESTAMPDIFF(SECOND,OPEN_DATE,
IFNULL(IFNULL(CLOSED_DATE,PENDING_CONFIRMATION_DATE),NOW())
) AS agedSec
FROM TICKETANALYSIS
WHERE OPEN_DATE BETWEEN '2014-03-01 00:00:00' AND '2014-06-05 23:59:59'
AND TICKETANALYSIS.ORG = 'AWSIE'
AND IFNULL(IFNULL(CLOSED_DATE,PENDING_CONFIRMATION_DATE),NOW())
>= '2014-03-02 00:00:00'
AND TIMESTAMPDIFF(SECOND,OPEN_DATE,
IFNULL(IFNULL(CLOSED_DATE,PENDING_CONFIRMATION_DATE),NOW()))
BETWEEN 1*24*60*60 AND 2*24*60*60
ORDER BY OPEN_DATE