clickhouse表、字段等查询语句
clickhouse部分查询语句
1.查询数据库所有表。
select table from system.parts where database = economic_brain group by table
2.查询数据库表所有字段
select distinct column from system.parts_columns where database=economic_brain and table=company
或
select name from system.columns where table=company
3.查询数据库中表name、count、size。
select table , sum(rows) as counts, formatReadableSize(sum(bytes_on_disk)) AS size from system.parts where database = economic_brain --数据库名称，自定义 group by table order by counts DESC;
4.arrayStringConcat和groupArray的运用，分组时合并数组为字符串。
select arrayStringConcat(groupArray(categoryCode),,) as categoryCode ,name,cateFirst from
(select cate_first name,left(category_code,2) categoryCode , cate_first cateFirst
from category_code GROUP BY categoryCode,cate_first)x GROUP BY name,cateFirst
