mysql 查询

aloneship

查询表结构表字段

1. SELECT
   
2.         T.TABLE_NAME,
   
3.         T.TABLE_COMMENT,
   
4.         C.COLUMN_NAME,
   
5.         C.COLUMN_COMMENT
   
6. FROM
   
7.         INFORMATION_SCHEMA.TABLES AS T
   
8.         INNER JOIN INFORMATION_SCHEMA.COLUMNS AS C ON T.TABLE_NAME = C.TABLE_NAME
   
9.         AND T.TABLE_SCHEMA = C.TABLE_SCHEMA
   
10. WHERE
    
11.         T.TABLE_SCHEMA = 'myerpoa';

复制代码

查看所有数据库容量大小

1. select
   
2.     table_schema as '数据库',
   
3.     sum(table_rows) as '记录数',
   
4.     sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',
   
5.     sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'
   
6.     from information_schema.tables
   
7.     group by table_schema
   
8.     order by sum(data_length) desc, sum(index_length) desc;

复制代码

查看所有数据库各表容量大小

1. select
   
2. table_schema as '数据库',
   
3. table_name as '表名',
   
4. table_rows as '记录数',
   
5. truncate(data_length/1024/1024, 2) as '数据容量(MB)',
   
6. truncate(index_length/1024/1024, 2) as '索引容量(MB)'
   
7. from information_schema.tables
   
8. order by data_length desc, index_length desc;

复制代码

查看指定数据库容量大小

1. select
   
2. table_schema as '数据库',
   
3. sum(table_rows) as '记录数',
   
4. sum(truncate(data_length/1024/1024, 2)) as '数据容量(MB)',
   
5. sum(truncate(index_length/1024/1024, 2)) as '索引容量(MB)'
   
6. from information_schema.tables
   
7. where table_schema='mysql';

复制代码

查看指定数据库各表容量大小

1. #例：查看mysql库各表容量大小
   
2. 
   
3. select
   
4. table_schema as '数据库',
   
5. table_name as '表名',
   
6. table_rows as '记录数',
   
7. truncate(data_length/1024/1024, 2) as '数据容量(MB)',
   
8. truncate(index_length/1024/1024, 2) as '索引容量(MB)'
   
9. from information_schema.tables
   
10. where table_schema='mysql'
    
11. order by data_length desc, index_length desc;

复制代码