一些SQL命令（不断更新，我总记不住，哭）
List
建库建表
GBK: CREATE DATABASE `test_db1` DEFAULT CHARACTER SET gbk COLLATE gbk_chinese_ci;
UTF-8: CREATE DATABASE `test_db2` DEFAULT CHARACTER SET utf8 COLLATE utf8_general_ci;
CREATE TABLE `test_table` (
`id` bigint(20) unsigned NOT NULL COMMENT '主键',
`gmt_create` datetime NOT NULL COMMENT '创建时间',
`content` varchar(20) DEFAULT NULL COMMENT '说明',
PRIMARY KEY (`id`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COMMENT='test create table'表的重命名(不区分大小写)
rename table haha to contestInfo; 列的重命名
mysql中：
alter table 数据表名 change 原列名 新列名 新列类型;
oracle中：
alter table 数据表名 rename 原列名 to 新列名; 编码
修改数据库编码 ALTER DATABASE `test` DEFAULT CHARACTER SET utf8 COLLATE utf8_bin
修改表编码 ALTER TABLE `category` DEFAULT CHARACTER SET utf8 COLLATE utf8_bin
修改字段编码 ALTER TABLE `test` CHANGE `dd` `dd` VARCHAR( 45 ) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL修改结构
mysql>
#表position增加列test
alter table position add(test char(10));
#表position修改列test
alter table position modify test char(20) not null;
#表position修改列test默认值
alter table position alter test set default 'system';
#表position去掉test默认值
alter table position alter test drop default;
#表position去掉列test
alter table position drop column test;
#表depart_pos删除主键
alter table depart_pos drop primary key;
#表depart_pos增加主键
alter table depart_pos add primary key PK_depart_pos (department_id,position_id);添加删除索引
show index from tblname;
ALTER TABLE table_name ADD INDEX index_name (column_list)
ALTER TABLE table_name ADD UNIQUE (column_list)
ALTER TABLE table_name ADD PRIMARY KEY (column_list)
CREATE INDEX index_name ON table_name (column_list)
CREATE UNIQUE INDEX index_name ON table_name (column_list)
DROP INDEX index_name ON talbe_name
ALTER TABLE table_name DROP INDEX index_name
ALTER TABLE table_name DROP PRIMARY KEY大批量删除
delete from contestinfo where `id`<3000;
select sleep(3);
delete from contestinfo where `id`<6000;
select sleep(3);
delete from contestinfo where `id`<9000;
...binlog相关
备库上执行一定要考虑事务是否写binlog
set session SQL_LOG_BIN = 0; //关闭，不写binlog
set session SQL_LOG_BIN = 1; //开启，写binlog，default
mysql>show master status; 查看当前正在使用的二进制日志
mysql>show binlog events in'mysql-bin.000001'; 查看二进制日志记录的事件[from position]
mysql>flush logs; 二进制日志滚动
mysql>show binary logs; 查看所有二进制日志
mysql>purge binary logs to 'mysql-bin.000003'; 删除二进制日志
Master_Log_File & Read_Master_Log_Pos：下一个传输的主日志信息。
Relay_Master_Log_File & Exec_Master_Log_Pos：下一个执行的主日志信息。
Relay_Log_File & Relay_Log_Pos：下一个执行的中继日志信息。
中继日志出错：
mysql> CHANGE MASTER TO
MASTER_LOG_FILE='<Relay_Master_Log_File>',
MASTER_LOG_POS=<Exec_Master_Log_Pos>;
mysql> START SLAVE;
stop slave ;
reset slave [ALL] relay logs,file and post，ALL will clear ip,port,user,pass;
CHANGE MASTER TO
MASTER_HOST='xxx.xxx.xxx.xxx',
MASTER_PORT=xxxx, 切记int
MASTER_USER='xxxxx',
MASTER_PASSWORD='xxxxx',
MASTER_LOG_FILE='mysql-bin.xxxxxx',
MASTER_LOG_POS=xxxxx; 切记int
start slave;select相关
查询时强制区分大小写
SELECT * FROM U WHERE binary name LIKE 'a%';
行号
SELECT
@row := @row + 1 as row,
t.*
FROM some_table t, (SELECT @row := 0) r
截取
SELECT
SUBSTRING_INDEX(phone,'-',2) AS PNumber,
SUBSTRING_INDEX(phone,'-', -1) AS Ext,
phone
FROM tb_user WHERE ucid=271338;
+--------------+------+-------------------+
| PNumber | Ext | phone |
+--------------+------+-------------------+
| 010-88888882 | 5612 | 010-88888882-5612 |
+--------------+------+-------------------+
拼接
UPDATE tb_user SET
phone=CONCAT( SUBSTRING_INDEX( phone,'-',2 ), '-', '1234' )
WHERE ucid = 271338;
+--------------+------+-------------------+
| PNumber | Ext | phone |
+--------------+------+-------------------+
| 010-88888882 | 1234 | 010-88888882-1234 |
+--------------+------+-------------------+
group_concat([DISTINCT] 要连接的字段 [Order BY ASC/DESC 排序字段] [Separator '分隔符'])
select id,group_concat(name order by name desc Separator ';') from aa group by id;
+------+---------------------------------------+
| id| group_concat(name order by name desc) |
+------+---------------------------------------+
|1 | 20;20;10 |
|2 | 20|
|3 | 500;200|
+------+---------------------------------------+
3 rows in set (0.00 sec)
数据库备份和恢复
mysqldump -h127.0.0.1 -uroot -P$MYSQL_PORT --default-character-set=utf8 -q -e --single-transaction --master-data=2 --result_file=/u01/bak/dump_${DB_NAME}.sql -B $candidates
content:
-- CHANGE MASTER TO MASTER_LOG_FILE='mysql-bin.000050', MASTER_LOG_POS=349656998;
CREATE DATABASE /*!32312 IF NOT EXISTS*/ `test_db_1` /*!40100 DEFAULT CHARACTER SET utf8 */;
USE `test_db_1`;
-n, --no-create-db
-t, --no-create-info
-d, --no-data
-B, --databases
-e, --extended-insert Use multiple-row INSERT syntax that include several VALUES lists.
-q, --quick Don't buffer query, dump directly to stdout.
--add-drop-database FALSE
--add-drop-table TRUE
--add-drop-trigger FALSE
--add-locks TRUE
--default-character-set=name utf8
--tz-utc TRUE SET TIME_ZONE='+00:00' at top of dump
--result_file 输出结果到
--single-transaction --master-data=2组合使用，保留位点
mysql -h localhost -P 6688 -u root -ptest database< test_db.sql