多列和 mutl table 内连接

Question

我需要对 tables 执行内部连接，其中有两个公共列 org_id 和 time_stamp 对通过 Athena

查询的 S3 中的 avro 格式数据

我试过了

SELECT year(from_iso8601_timestamp(em.time_stamp)) time_unit,
         sum(em.column1) column1,
         sum(spa.column2) column2,
         sum(vir.column3) column3
FROM "schemaName".table1 em
JOIN "schemaName".table2 spa
    ON year(from_iso8601_timestamp(em.time_stamp)) = year(from_iso8601_timestamp(spa.time_stamp))
        AND em.org_id = spa.org_id
JOIN "schemaName".table3 vir
    ON year(from_iso8601_timestamp(vir.time_stamp)) = year(from_iso8601_timestamp(spa.time_stamp))
        AND vir.org_id = spa.org_id
WHERE em.org_id = 'org_id_test'
        AND (from_iso8601_timestamp(em.time_stamp)) <= (cast(from_iso8601_timestamp('2019-11-22T23:59:31') AS timestamp))
        AND (from_iso8601_timestamp(em.time_stamp)) >= (cast(from_iso8601_timestamp('2019-11-22T23:59:31') AS timestamp) - interval '10' year)
GROUP BY  em.org_id, year(from_iso8601_timestamp(em.time_stamp))
ORDER BY  time_unit DESC limit 11

但我得到的有点像交叉连接

results
    time_unit   |column1    |column2    |column3
1   2019        |48384      |299040     |712

而如果我在相同的 where 条件下分别聚合每个 table，则值显示为

table1
column1

    504

table2
column2

    280

table3
column3

    5

有人可以帮我弄清楚我做错了什么以及实现它的正确方法吗？

Answer 1

如果我没听错，发生的事情是，因为有多个记录匹配每个连接中的条件，所以你最终会多次计算同一条记录你聚合。

解决此问题的典型方法是在子查询中聚合，然后加入。

您可能正在寻找这样的东西：

select 
    em.time_unit,
    em.column1,
    spa.column2,
    vir.column3
from (
    select 
        org_id,
        year(from_iso8601_timestamp(time_stamp)) time_unit,
        sum(column1) column1
    from "schemaname".table1
    group by org_id, year(from_iso8601_timestamp(time_stamp))
) em
join (
    select 
        org_id,
        year(from_iso8601_timestamp(time_stamp)) time_unit,
        sum(column2) column2
    from "schemaname".table2
    group by org_id, year(from_iso8601_timestamp(time_stamp))
) spa on spa.time_unit = em.time_unit and spa.org_id = em.org_id
join (
    select 
        org_id,
        year(from_iso8601_timestamp(time_stamp)) time_unit,
        sum(column3) column3
    from "schemaname".table3
    group by org_id, year(from_iso8601_timestamp(time_stamp))
) vir on vir.time_unit = em.time_unit and vir.org_id = em.org_id
where 
    em.org_id = 'org_id_test'
    and em.time_unit between 2009 and 2019
order by em.time_unit desc 
limit 11

多列和 mutl table 内连接

Mutli column and mutl table inner join

sql

amazon-athena