sql - 如何选择显示自特定谓词出现最后时刻以来的天数的行？

Question

我有一个表格，其中的数据如下所示：

KEYWORD, CONVERSIONS, CREATED_AT
'Travel agent', 0, '2015-04-01'
'Travel agent', 0, '2015-04-02'
'Travel agent', 0, '2015-04-03'
'Travel agent', 0, '2015-04-04'
'Travel agent', 0, '2015-04-05'
'Travel agent', 0, '2015-04-06'
'Travel agent', 0, '2015-04-07'
'Travel agent', 0, '2015-04-08'
'Travel agent', 0, '2015-04-09'
'Travel agency vizier', 0, '2015-04-01'
'Travel agency vizier', 0, '2015-04-02'
'Travel agency vizier', 0, '2015-04-03'
'Travel agency vizier', 0, '2015-04-04'
'Travel agency vizier', 0, '2015-04-05'
'Travel agency vizier', 0, '2015-04-06'
'Travel agency vizier', 0, '2015-04-07'
'Travel agency vizier', 0, '2015-04-08'
'Travel agency vizier', 1, '2015-04-09'
'Coral', 0, '2015-04-01'
'Coral', 0, '2015-04-02'
'Coral', 0, '2015-04-03'
'Coral', 0, '2015-04-04'
'Coral', 0, '2015-04-05'
'Coral', 0, '2015-04-06'
'Coral', 0, '2015-04-07'
'Coral', 0, '2015-04-08'
'Coral', 0, '2015-04-09'
'Coral travel', 0, '2015-04-01'
'Coral travel', 0, '2015-04-02'
'Coral travel', 0, '2015-04-03'
'Coral travel', 0, '2015-04-04'
'Coral travel', 0, '2015-04-05'
'Coral travel', 0, '2015-04-06'
'Coral travel', 0, '2015-04-07'
'Coral travel', 0, '2015-04-08'
'Coral travel', 0, '2015-04-09'
'Egypt last minute', 1, '2015-04-01'
'Egypt last minute', 1, '2015-04-02'
'Egypt last minute', 0, '2015-04-03'
'Egypt last minute', 0, '2015-04-04'
'Egypt last minute', 0, '2015-04-05'
'Egypt last minute', 0, '2015-04-06'
'Egypt last minute', 0, '2015-04-07'
'Egypt last minute', 0, '2015-04-08'
'Egypt last minute', 0, '2015-04-09'
'Egypt holidays', 0, '2015-04-01'
'Egypt holidays', 0, '2015-04-02'
'Egypt holidays', 0, '2015-04-03'
'Egypt holidays', 0, '2015-04-04'
'Egypt holidays', 0, '2015-04-05'
'Egypt holidays', 0, '2015-04-06'
'Egypt holidays', 0, '2015-04-07'
'Egypt holidays', 0, '2015-04-08'
'Egypt holidays', 0, '2015-04-09'
'Exim', 0, '2015-04-01'
'Exim', 0, '2015-04-02'
'Exim', 0, '2015-04-03'
'Exim', 0, '2015-04-04'
'Exim', 0, '2015-04-05'
'Exim', 0, '2015-04-06'
'Exim', 0, '2015-04-07'
'Exim', 0, '2015-04-08'
'Exim', 0, '2015-04-09'
'Greece last minute', 0, '2015-04-03'
'Greece last minute', 0, '2015-04-04'
'Greece last minute', 0, '2015-04-05'
'Greece last minute', 0, '2015-04-06'
'Greece last minute', 0, '2015-04-07'
'Greece last minute', 0, '2015-04-08'
'Greece last minute', 0, '2015-04-09'
'Greece holidays', 0, '2015-04-01'
'Greece holidays', 0, '2015-04-02'
'Greece holidays', 0, '2015-04-03'
'Greece holidays', 0, '2015-04-04'
'Greece holidays', 0, '2015-04-05'
'Greece holidays', 0, '2015-04-06'
'Greece holidays', 0, '2015-04-07'
'Greece holidays', 0, '2015-04-08'
'Greece holidays', 0, '2015-04-09'
'Last-minute', 0, '2015-04-01'
'Last-minute', 0, '2015-04-02'
'Last-minute', 0, '2015-04-03'
'Last-minute', 0, '2015-04-04'
'Last-minute', 0, '2015-04-05'
'Last-minute', 0, '2015-04-06'
'Last-minute', 0, '2015-04-07'
'Last-minute', 0, '2015-04-08'
'Last-minute', 0, '2015-04-09'
'Last Minute', 1, '2015-04-01'
'Last Minute', 1, '2015-04-02'
'Last Minute', 0, '2015-04-03'
'Last Minute', 0, '2015-04-04'
'Last Minute', 0, '2015-04-05'
'Last Minute', 0, '2015-04-06'
'Last Minute', 0, '2015-04-07'
'Last Minute', 0, '2015-04-08'
'Last Minute', 0, '2015-04-09'
'Last Minute Egypt', 0, '2015-04-01'
'Last Minute Egypt', 0, '2015-04-02'
'Last Minute Egypt', 0, '2015-04-03'
'Last Minute Egypt', 0, '2015-04-04'
'Last Minute Egypt', 0, '2015-04-05'
'Last Minute Egypt', 0, '2015-04-06'
'Last Minute Egypt', 0, '2015-04-07'
'Last Minute Egypt', 0, '2015-04-08'
'Last Minute Egypt', 0, '2015-04-09'
'Last minute holidays', 0, '2015-04-01'
'Last minute holidays', 0, '2015-04-02'
'Last minute holidays', 0, '2015-04-03'
'Last minute holidays', 0, '2015-04-04'
'Last minute holidays', 0, '2015-04-05'
'Last minute holidays', 0, '2015-04-06'
'Last minute holidays', 0, '2015-04-07'
'Last minute holidays', 0, '2015-04-08'
'Last minute holidays', 0, '2015-04-09'
'Offer holiday', 0, '2015-04-01'
'Offer holiday', 0, '2015-04-02'
'Offer holiday', 0, '2015-04-03'
'Offer holiday', 0, '2015-04-04'
'Offer holiday', 0, '2015-04-05'
'Offer holiday', 0, '2015-04-06'
'Offer holiday', 0, '2015-04-07'
'Offer holiday', 0, '2015-04-08'
'Offer holiday', 0, '2015-04-09'
'Sun & fun', 0, '2015-04-01'
'Sun & fun', 0, '2015-04-02'
'Sun & fun', 0, '2015-04-03'
'Sun & fun', 0, '2015-04-04'
'Sun & fun', 0, '2015-04-05'
'Sun & fun', 0, '2015-04-06'
'Sun & fun', 0, '2015-04-07'
'Sun & fun', 0, '2015-04-08'
'Sun & fun', 2, '2015-04-09'
'Sun and fun', 0, '2015-04-01'
'Sun and fun', 0, '2015-04-02'
'Sun and fun', 0, '2015-04-03'
'Sun and fun', 0, '2015-04-04'
'Sun and fun', 0, '2015-04-05'
'Sun and fun', 0, '2015-04-06'
'Sun and fun', 0, '2015-04-07'
'Sun and fun', 0, '2015-04-08'
'Sun and fun', 1, '2015-04-09'
'Lodge', 0, '2015-04-01'
'Lodge', 0, '2015-04-02'
'Lodge', 0, '2015-04-03'
'Lodge', 0, '2015-04-04'
'Lodge', 0, '2015-04-05'
'Lodge', 1, '2015-04-06'
'Lodge', 1, '2015-04-07'
'Lodge', 1, '2015-04-08'
'Lodge', 0, '2015-04-09'
'Holiday greece', 0, '2015-04-01'
'Holiday greece', 0, '2015-04-02'
'Holiday greece', 0, '2015-04-03'
'Holiday greece', 0, '2015-04-04'
'Holiday greece', 0, '2015-04-05'
'Holiday greece', 0, '2015-04-06'
'Holiday greece', 0, '2015-04-07'
'Holiday greece', 0, '2015-04-08'
'Holiday greece', 0, '2015-04-09'
'Holiday', 4, '2015-04-01'
'Holiday', 4, '2015-04-02'
'Holiday', 1, '2015-04-03'
'Holiday', 1, '2015-04-04'
'Holiday', 1, '2015-04-05'
'Holiday', 3, '2015-04-06'
'Holiday', 3, '2015-04-07'
'Holiday', 3, '2015-04-08'
'Holiday', 3, '2015-04-09'
'Wakacje.pl', 13, '2015-04-01'
'Wakacje.pl', 13, '2015-04-02'
'Wakacje.pl', 1, '2015-04-03'
'Wakacje.pl', 1, '2015-04-04'
'Wakacje.pl', 1, '2015-04-05'
'Wakacje.pl', 6, '2015-04-06'
'Wakacje.pl', 6, '2015-04-07'
'Wakacje.pl', 6, '2015-04-08'
'Wakacje.pl', 4, '2015-04-09'
'Holiday 2014', 0, '2015-04-01'
'Holiday 2014', 0, '2015-04-02'
'Holiday greece', 1, '2015-04-01'
'Holiday greece', 1, '2015-04-02'
'Holiday greece', 0, '2015-04-03'
'Holiday greece', 0, '2015-04-04'
'Holiday greece', 0, '2015-04-05'
'Holiday greece', 0, '2015-04-06'
'Holiday greece', 0, '2015-04-07'
'Holiday greece', 0, '2015-04-08'
'Holiday greece', 0, '2015-04-09'
'Last-minute holiday', 0, '2015-04-01'
'Last-minute holiday', 0, '2015-04-02'
'Last-minute holiday', 0, '2015-04-03'
'Last-minute holiday', 0, '2015-04-04'
'Last-minute holiday', 0, '2015-04-05'
'Last-minute holiday', 0, '2015-04-06'
'Last-minute holiday', 0, '2015-04-07'
'Last-minute holiday', 0, '2015-04-08'
'Last-minute holiday', 1, '2015-04-09'
'Holiday last minute', 0, '2015-04-01'
'Holiday last minute', 0, '2015-04-02'
'Holiday last minute', 0, '2015-04-03'
'Holiday last minute', 0, '2015-04-04'
'Holiday last minute', 0, '2015-04-05'
'Holiday last minute', 0, '2015-04-06'
'Holiday last minute', 0, '2015-04-07'
'Holiday last minute', 0, '2015-04-08'
'Holiday last minute', 0, '2015-04-09'
'Vacation en', 0, '2015-04-01'
'Vacation en', 0, '2015-04-02'
'Vacation en', 0, '2015-04-03'
'Vacation en', 0, '2015-04-04'
'Vacation en', 0, '2015-04-05'
'Vacation en', 0, '2015-04-06'
'Vacation en', 0, '2015-04-07'
'Vacation en', 0, '2015-04-08'
'Vacation en', 0, '2015-04-09'
'Holiday in Greece', 0, '2015-04-01'
'Holiday in Greece', 0, '2015-04-02'
'Holiday in Greece', 0, '2015-04-03'
'Holiday in Greece', 0, '2015-04-04'
'Holiday in Greece', 0, '2015-04-05'
'Holiday in Greece', 0, '2015-04-06'
'Holiday in Greece', 0, '2015-04-07'
'Holiday in Greece', 0, '2015-04-08'
'Holiday in Greece', 1, '2015-04-09'
'Holidays abroad', 0, '2015-04-01'
'Holidays abroad', 0, '2015-04-02'
'Holidays abroad', 0, '2015-04-03'
'Holidays abroad', 0, '2015-04-04'
'Holidays abroad', 0, '2015-04-05'
'Holidays abroad', 0, '2015-04-06'
'Holidays abroad', 0, '2015-04-07'
'Holidays abroad', 0, '2015-04-08'
'Holidays abroad', 0, '2015-04-09'
'Holiday', 0, '2015-04-01'
'Holiday', 0, '2015-04-02'
'Holiday', 1, '2015-04-03'
'Holiday', 1, '2015-04-04'
'Holiday', 1, '2015-04-05'
'Holiday', 0, '2015-04-06'
'Holiday', 0, '2015-04-07'
'Holiday', 0, '2015-04-08'
'Holiday', 0, '2015-04-09'
'Egypt holiday last minute', 0, '2015-04-01'
'Egypt holiday last minute', 0, '2015-04-02'
'Egypt holiday last minute', 0, '2015-04-03'
'Egypt holiday last minute', 0, '2015-04-04'
'Egypt holiday last minute', 0, '2015-04-05'
'Egypt holiday last minute', 0, '2015-04-06'
'Egypt holiday last minute', 0, '2015-04-07'
'Egypt holiday last minute', 0, '2015-04-08'
'Egypt holiday last minute', 0, '2015-04-09'
'Holiday greece', 0, '2015-04-01'
'Holiday greece', 0, '2015-04-02'
'Holiday greece', 0, '2015-04-03'
'Holiday greece', 0, '2015-04-04'
'Holiday greece', 0, '2015-04-05'
'Holiday greece', 0, '2015-04-06'
'Holiday greece', 0, '2015-04-07'
'Holiday greece', 0, '2015-04-08'
'Holiday greece', 0, '2015-04-09'
'Travel abroad', 0, '2015-04-01'
'Travel abroad', 0, '2015-04-02'
'Travel abroad', 0, '2015-04-03'
'Travel abroad', 0, '2015-04-04'
'Travel abroad', 0, '2015-04-05'
'Travel abroad', 1, '2015-04-06'
'Travel abroad', 1, '2015-04-07'
'Travel abroad', 1, '2015-04-08'
'Travel abroad', 0, '2015-04-09'
'Vizier holidays', 1, '2015-04-01'
'Vizier holidays', 1, '2015-04-02'
'Vizier holidays', 0, '2015-04-03'
'Vizier holidays', 0, '2015-04-04'
'Vizier holidays', 0, '2015-04-05'
'Vizier holidays', 0, '2015-04-06'
'Vizier holidays', 0, '2015-04-07'
'Vizier holidays', 0, '2015-04-08'
'Vizier holidays', 0, '2015-04-09'
'Www vacation en ', 0,' 2015-04-01 '
'Www vacation en ', 0,' 2015-04-02 '
'Www vacation en ', 0,' 2015-04-03 '
'Www vacation en ', 0,' 2015-04-04 '
'Www vacation en ', 0,' 2015-04-05 '
'Www vacation en ', 0,' 2015-04-06 '
'Www vacation en ', 0,' 2015-04-07 '
'Www vacation en ', 0,' 2015-04-08 '
'Www vacation en ', 1,' 2015-04-09 '
'Trips', 0, '2015-04-01'
'Trips', 0, '2015-04-02'
'Trips', 0, '2015-04-03'
'Trips', 0, '2015-04-04'
'Trips', 0, '2015-04-05'
'Trips', 0, '2015-04-06'
'Trips', 0, '2015-04-07'
'Trips', 0, '2015-04-08'
'Trips', 0, '2015-04-09'
'Tours', 0, '2015-04-01'
'Tours', 0, '2015-04-02'
'Tours', 0, '2015-04-03'
'Tours', 0, '2015-04-04'
'Tours', 0, '2015-04-05'
'Tours', 0, '2015-04-06'
'Tours', 0, '2015-04-07'
'Tours', 0, '2015-04-08'
'Tours', 0, '2015-04-09'
'Trips abroad', 0, '2015-04-01'
'Trips abroad', 0, '2015-04-02'
'Trips abroad', 0, '2015-04-03'
'Trips abroad', 0, '2015-04-04'
'Trips abroad', 0, '2015-04-05'
'Trips abroad', 0, '2015-04-06'
'Trips abroad', 0, '2015-04-07'
'Trips abroad', 0, '2015-04-08'
'Trips abroad', 0, '2015-04-09'

它是 Google Analytics API 报告的一部分。 KEYWORD列包含用于为网站做广告的关键字，列包含 CONVERSIONS在中命名的日期的转化次数CREATED_AT。

具体谓词是date range： WHERE '2015-04-01' <= created_at AND created_at <= '2015-04-09'

我尝试编写的查询应该打印自上次转换以来的天数和上次转换的日期（如果没有转换，则为 null/'never' date range）。所以我正在寻找的结果看起来像这样today（CURRENT_DATE = '2015-04-10'）：

KEYWORD, DAYS_SINCE_CONVERSION, LAST_CONVERSION_DATE
'Travel agent', null, null
'Travel agency vizier', 1, '2015-04-09'
'Egypt last minute', 8, '2015-04-02'
'Exim', null, null
'Last Minute', 8, '2015-04-02'
'Sun & fun', 1, '2015-04-09'
... (and so on - I gave here few keywords just for example)

我尝试了一些 SQL，但没有任何运气，我在这里没有任何可分享的内容，因为我什至没有接近预期的结果。:-(

score 2 · Accepted Answer

您标记了您的问题，postgresql-9.4因此您可以为此使用过滤的聚合：

select keyword, 
       max(created_at) filter (WHERE conversions > 0 AND created_at between '2015-04-01' AND '2015-04-09') as last_conversion_date
from conversion
group by keyword;

这将为每个关键字和给定时间范围内的最新日期返回一行，created_at但前提是存在转换（必须过滤掉，例如'Travel agent', 0, '2015-04-09'

要计算此后的天数，只需从中减去最新日期即可current_date。为了不重复表达式，更容易将查询放入派生表中：

select keyword, 
       current_date - last_conversion_date as days_since_conversion, 
       last_conversion_date
from (
  select keyword, 
         max(created_at) filter (WHERE conversions > 0 AND created_at between '2015-04-01' AND '2015-04-09') as last_conversion_date
  from conversion
  group by keyword
) t
order by keyword;

date '2015-04-01'是用于编写日期文字的 SQL 标准语法，我更喜欢它而不是仅使用字符串的隐式日期样式。

SQLFiddle在这里：http ://sqlfiddle.com/#!15/d9aff/1

SQLFiddle 使用case when表达式而不是filter表达式，因为filter在早期的 Postgres 版本中不可用。

score 1 · Accepted Answer

这是我的方法（可能与数据库无关，但不要相信我的话）：

select c.keyword, t.days_since, t.last_date from conversation c
left join (
  select keyword, current_date - max(created_at) as days_since, max(created_at) as last_date
  from conversation
  where created_at between '2015-04-01' and '2015-04-09'
  and conversations > 0
  group by keyword
) t on t.keyword = c.keyword
group c.keyword, t.days_since, t.last_date

sql - 如何选择显示自特定谓词出现最后时刻以来的天数的行？

2 回答 2

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