1. mysqldump 命令的使用
备份和导出数据库
mysqldump -h database_ip -u Username -p --opt databasename > backup-file.sql
只导出数据库表结构
mysqldump -h database_ip -d -u Username -p databasename >database_structure.sql
只导出数据库中的某个表
mysqldump --opt --add-drop-table -u Username -p databasename tablename > dump.sql
如果不想手工输入密码 请使用–password 参数
mysqldump -h database_ip -u Username --password=123456 --opt databasename > backup-file.sqlmysqldump -h database_ip -d -u Username --password=123456 databasename >database_structure.sql
2. mysql 命令使用
将查询结果保存到文件select title from book into outfile '/tmp/outfile.txt';
查找表中多余的重复记录，重复记录是根据某个字段（peopleId）来判断
select * from people where peopleId in (select peopleId from people group by peopleId having count(peopleId) > 1);
查询表中不重复记录(排除重复记录)
select * from phome_ecms_wma where title in (select distinct title from phome_ecms_wma);
删除表中重复记录,重复记录是根据某个字段（title）来判断
select *,count(distinct title) INTO OUTFILE '/tmp/table.bak' from phome_ecms_wma group by title;delete from phome_ecms_wma;LOAD DATA INFILE '/tmp/table.bak' REPLACE INTO TABLE phome_ecms_wma character set utf8;
查询数据库当前编码
mysql> show variables like "character_set%";
修改表字段类型
mysql> alter table table_name change last_action last_action datetime NOT NULL default '0000-00-00 00:00:00';
给表添加一个新字段
mysql> ALTER TABLE host ADD ks_mac VARCHAR(100);
从表中删除一个字段
mysql> ALTER TABLE table_name DROP field_name;
重命名表
mysql>alter table t1 rename t2;
给字段加索引
mysql> alter table tablename add index 索引名 (字段名1[，字段名2 …]);mysql> alter table tablename add index emp_name (name);
加主关键字的索引
mysql> alter table tablename add primary key(id);
加唯一限制条件的索引
mysql> alter table tablename add unique emp_name2(cardnumber);
删除某个索引
mysql>alter table tablename drop index emp_name;
远程访问mysql 设置
mysql> GRANT ALL PRIVILEGES ON database_test.* to root@192.168.1.9 IDENTIFIED BY '123456';mysql> FLUSH PRIVILEGES;
