mysql - mysql中选定表的分组大小

Question

我正在尝试获取符合我的条件的所有表的总大小(拉丁列，其中表排序规则不是拉丁文，带有文本或 varchar 列)，但是我得到的大小与实际大小相差甚远尺寸。

mysql> select t.table_schema,sum(data_length + index_length)/1024/1024/1024 
    from tables t 
    inner join columns c on t.table_schema=c.table_schema and t.table_name=c.table_name 
    where t.table_schema in ('db1','db2') 
        and  (c.collation_name like '%latin%' or c.character_set_name like '%latin%') 
        and  (c.column_type like 'varchar%' or c.column_type like 'text') 
        and  t.table_collation not like '%latin%' 
    group by t.table_schema;
+--------------+------------------------------------------------+
| table_schema | sum(data_length + index_length)/1024/1024/1024 |
+--------------+------------------------------------------------+
| db1       |                                  233.021102905273 |
| db2        |                                  93.742004394531 |
+--------------+------------------------------------------------+
2 rows in set (0.54 sec)

Answer 1

您需要连接一个子查询，该子查询仅返回每个表中与列约束匹配的一行。

select t.table_schema,sum(data_length + index_length)/1024/1024/1024 
from tables t 
inner join (
    SELECT DISTINCT table_schema, table_name
    FROM columns  
    WHERE (collation_name like '%latin%' or character_set_name like '%latin%') 
    and (column_type like 'varchar%' or column_type like 'text') 
) c on t.table_schema=c.table_schema and t.table_name=c.table_name
where t.table_schema in ('db1','db2') 
    and  t.table_collation not like '%latin%' 
group by t.table_schema;