Sql 行聚合上的Case语句
我正在使用标准SQL进行Google大查询 我有页面浏览数据。所有相关的是Sql 行聚合上的Case语句,sql,google-bigquery,Sql,Google Bigquery,我正在使用标准SQL进行Google大查询 我有页面浏览数据。所有相关的是 | user_id | entity_id | url | URL的格式可以是/entities/entity\u id/show或entities/entity\u id/reply/new 一个用户可能会出现在任何一种、两种或两种类型的URL中,并且可能会重复出现 我的目标是一张像这样的桌子 | user_id | entity_id | view_type | | user_id | entity_id |
| user_id | entity_id | url |
URL的格式可以是/entities/entity\u id/show
或entities/entity\u id/reply/new
一个用户可能会出现在任何一种、两种或两种类型的URL中,并且可能会重复出现
我的目标是一张像这样的桌子
| user_id | entity_id | view_type |
| user_id | entity_id | url |
----------------------------------------------------
| 1 | 23 | '/entities/23/replies/new' |
| 1 | 23 | '/entities/23/show' |
| 2 | 30 | '/entities/30/show' |
其中,view\u type
为“显示”或“新建”
每个用户/实体对只能有一行<如果用户id
/实体id
对曾经出现在表单/entities/entity\u id/回复/new
的一个url旁边,则code>视图类型应为“new”,但如果该对没有“new”url,则为“show”。如果原始表中没有用户id
/实体id
对的示例,则最终表中应该没有这些示例
我将包括一个with语句,其中包含用于重复性的示例数据
WITH data AS (
select 1 as user_id, 23 as entity_id, '/entities/23/replies/new' as url
UNION ALL
select 1 as user_id, 23 as entity_id, '/entities/23/show' as url
UNION ALL
select 2 as user_id, 30 as entity_id, '/entities/30/show' as url
)
SELECT * from data
那就摆了一张这样的桌子
| user_id | entity_id | view_type |
| user_id | entity_id | url |
----------------------------------------------------
| 1 | 23 | '/entities/23/replies/new' |
| 1 | 23 | '/entities/23/show' |
| 2 | 30 | '/entities/30/show' |
我可以通过两个语句来实现我的目标,这两个语句对任何一种url执行选择distinct
,然后返回并执行一个case
语句,该语句对给定的用户
/实体
对有无连接进行操作
我的意思是:
WITH data AS (
select 1 as user_id, 23 as entity_id, '/entities/23/replies/new' as url
UNION ALL
select 1 as user_id, 23 as entity_id, '/entities/23/show' as url
UNION ALL
select 2 as user_id, 30 as entity_id, '/entities/30/show' as url
), news AS (
SELECT DISTINCT user_id, entity_id, 1 as found
FROM data
WHERE url like '%new'
), shows AS (
SELECT DISTINCT user_id, entity_id, 1 as found
FROM data
WHERE url like '%show'
)
SELECT DISTINCT d.user_id,
d.entity_id,
CASE WHEN n.found = 1 then 'new'
WHEN s.found = 1 then 'show' end as view_type
FROM data d
LEFT JOIN news n on n.user_id = d.user_id and n.entity_id = d.entity_id
LEFT JOIN shows s on s.user_id = d.user_id and s.entity_id = d.entity_id
显然,样例数据使它看起来比实际更令人畏惧,但这仍然是一个相当笨拙、不可读的查询,如果我添加另一个<代码> VIEWIONTYPE ,我想考虑一下,这是一个痛苦的延伸。
我想一定有更好的办法
我突然想到,我可以尝试将用户id
/实体id
对的所有URL填充到一个数组中,然后用case
语句对数组进行操作,比如“如果数组中的任何元素匹配“new”然后“new”,等等。)。但我不确定如何做“任何元素regex匹配”“如果可能的话
我很感激任何人能给予我的洞察力 一种方法是聚合:
SELECT user_id, entity_id,
(CASE WHEN COUNTIF(url like '%new') > 0 THEN 'new' ELSE 'show'
END) as view_type
FROM data
GROUP BY user_id, entity_id
是的,这正是我所希望的。谢谢