Mysql笔记--常用命令

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查看建表语句

show create table tableName;

eg:

mysql> show create table demo;+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table                                                                                                                                                                                                                                                           |+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| demo  | CREATE TABLE `demo` (  `uid` bigint(20) unsigned NOT NULL AUTO_INCREMENT,  `uname` varchar(500) DEFAULT NULL,  `email` varchar(500) DEFAULT NULL,  `createTime` datetime DEFAULT NULL,  PRIMARY KEY (`uid`)) ENGINE=MyISAM AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 |+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)

可以看到该表使用的数据引擎事 MyISAM (该引擎不支持事务)

查看可使用的数据引擎

show engines;

eg:

mysql> show engines;+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+| Engine             | Support | Comment                                                        | Transactions | XA   | Savepoints |+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+| MyISAM             | YES     | MyISAM storage engine                                          | NO           | NO   | NO         || CSV                | YES     | CSV storage engine                                             | NO           | NO   | NO         || MRG_MYISAM         | YES     | Collection of identical MyISAM tables                          | NO           | NO   | NO         || BLACKHOLE          | YES     | /dev/null storage engine (anything you write to it disappears) | NO           | NO   | NO         || MEMORY             | YES     | Hash based, stored in memory, useful for temporary tables      | NO           | NO   | NO         || FEDERATED          | NO      | Federated MySQL storage engine                                 | NULL         | NULL | NULL       || ARCHIVE            | YES     | Archive storage engine                                         | NO           | NO   | NO         || PERFORMANCE_SCHEMA | YES     | Performance Schema                                             | NO           | NO   | NO         || InnoDB             | DEFAULT | Supports transactions, row-level locking, and foreign keys     | YES          | YES  | YES        |+--------------------+---------+----------------------------------------------------------------+--------------+------+------------+9 rows in set (0.00 sec)

可以看到只有InnoDB引擎才支持事务

修改表的数据引擎

alter table tableName engine=innodb;

eg:

mysql> alter table demo engine=innodb;Query OK, 1 row affected (0.58 sec)Records: 1  Duplicates: 0  Warnings: 0mysql> show create table demo;+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| Table | Create Table                                                                                                                                                                                                                                                           |+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+| demo  | CREATE TABLE `demo` (  `uid` bigint(20) unsigned NOT NULL AUTO_INCREMENT,  `uname` varchar(500) DEFAULT NULL,  `email` varchar(500) DEFAULT NULL,  `createTime` datetime DEFAULT NULL,  PRIMARY KEY (`uid`)) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8 |+-------+------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------+1 row in set (0.00 sec)

修改默认的存储引擎

修改my.cnf文件,在[mysqld]下加入:

default-storage-engine=INNODB

修改默认的字符集

修改my.cnf文件,在[mysqld]下加入:

# charsetdefault-character-set=utf8default-collation=utf8_general_cicharacter-set-server=utf8collation-server=utf8_general_ciinit-connect='SET NAMES utf8'

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