【查阅】mysql系统视图查看

【1】查看表大小

SELECT
    CONCAT(table_schema,'.',table_name) AS 'Table Name',
    table_rows AS 'Number of Rows',
    CONCAT(ROUND(data_length/(1024*1024),3),' MB') AS 'Data Size',
    CONCAT(ROUND(index_length/(1024*1024),3),' MB') AS 'Index Size',
    CONCAT(ROUND((data_length+index_length)/(1024*1024),3),' MB') AS 'Total Size'
FROM
    information_schema.TABLES
WHERE
    table_schema = 'test' AND table_name in ('test101','test102');

 【2】基本命令

【2.1】查看数据库版本：show variables like 'version';
【2.2】列出所有数据库：show databases;
【2.3】查看服务器状态：status；
【2.4】查看数据库存储引擎：show engines;
【2.5】查看数据库存储引擎插件：show plugins;
【2.6】查看数据库状态统计：show status;
【2.7】查看数据库参数：show variables;
【2.8】查看复制容灾：show master status; show slave status;
【2.9】查看单机还是集群：show variables like '%ckuster%';
【2.10】查看触发器，查看存储过程: show triggers;     show procedure status;
【2.11】查看当前mysql的线程：show process list;
【2.12】查看用户授权：show grants for root;
【2.13】更多
show table……
show index……
【2.14】查看当前会话的CRUD等次数：show status like 'com_%';
【2.15】查看字符集：show character set; show variables like 'character%';
【2.16】查看排序规则：show collation;
【2.17】查看数据库排序规则：show variables like 'collation%';

 【3】系统视图

【3.1】查看字符集：select * from information_schema.character_sets;
【3.2】查看排序规则：select * from information_schema.collations;