每小時SQL輸出唯一訪問者

Question

當談到SQL時，我很新手，上週工作時遇到問題。我能夠通過RoR查詢得到它並根據需要重新格式化數據（凌亂的D：）;但是，我真的想知道SQL的解決它，如果有任何

我有一個MySQL數據庫看起來像這樣

| id | unique_visitors |  time_period | 
| 1 |    16 | 2013-07-01 00:00:00 | 
| 2 |    20 | 2013-07-01 01:00:00 | 
| 3 |    2 | 2013-07-01 02:00:00 | 

最終的輸出，我需要看起來像這樣

| date | 00 | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 |.... | 22 | 23| 
| 2013-07-01 | 16 | 20 | 2 | 32 | .........      

每一行都會顯示日期和每小時的唯一訪客。

我不確定這是否可能與sql查詢，並真的想借此機會學習一些東西。

謝謝SQL大師！

Answer 1

它與CASE陳述變得複雜，但在這裏你是。我覺得自己像一個挑戰睡前

表統計（ID，unique_visitors，TIME_PERIOD）

select DATE_FORMAT(time_period ,'%Y-%m-%d') as date, 
sum(CASE WHEN EXTRACT(hour from time_period) = 00 THEN unique_visitors ELSE 0 END) as '00', 
sum(CASE WHEN EXTRACT(hour from time_period) = 01 THEN unique_visitors ELSE 0 END) as '01', 
sum(CASE WHEN EXTRACT(hour from time_period) = 02 THEN unique_visitors ELSE 0 END) as '02', 
sum(CASE WHEN EXTRACT(hour from time_period) = 03 THEN unique_visitors ELSE 0 END) as '03', 
sum(CASE WHEN EXTRACT(hour from time_period) = 04 THEN unique_visitors ELSE 0 END) as '04', 
sum(CASE WHEN EXTRACT(hour from time_period) = 05 THEN unique_visitors ELSE 0 END) as '05', 
sum(CASE WHEN EXTRACT(hour from time_period) = 06 THEN unique_visitors ELSE 0 END) as '06', 
sum(CASE WHEN EXTRACT(hour from time_period) = 07 THEN unique_visitors ELSE 0 END) as '07', 
sum(CASE WHEN EXTRACT(hour from time_period) = 08 THEN unique_visitors ELSE 0 END) as '08', 
sum(CASE WHEN EXTRACT(hour from time_period) = 09 THEN unique_visitors ELSE 0 END) as '09', 
sum(CASE WHEN EXTRACT(hour from time_period) = 10 THEN unique_visitors ELSE 0 END) as '10', 
sum(CASE WHEN EXTRACT(hour from time_period) = 11 THEN unique_visitors ELSE 0 END) as '11', 
sum(CASE WHEN EXTRACT(hour from time_period) = 12 THEN unique_visitors ELSE 0 END) as '12', 
sum(CASE WHEN EXTRACT(hour from time_period) = 13 THEN unique_visitors ELSE 0 END) as '13', 
sum(CASE WHEN EXTRACT(hour from time_period) = 14 THEN unique_visitors ELSE 0 END) as '14', 
sum(CASE WHEN EXTRACT(hour from time_period) = 15 THEN unique_visitors ELSE 0 END) as '15', 
sum(CASE WHEN EXTRACT(hour from time_period) = 16 THEN unique_visitors ELSE 0 END) as '16', 
sum(CASE WHEN EXTRACT(hour from time_period) = 17 THEN unique_visitors ELSE 0 END) as '17', 
sum(CASE WHEN EXTRACT(hour from time_period) = 18 THEN unique_visitors ELSE 0 END) as '18', 
sum(CASE WHEN EXTRACT(hour from time_period) = 19 THEN unique_visitors ELSE 0 END) as '19', 
sum(CASE WHEN EXTRACT(hour from time_period) = 20 THEN unique_visitors ELSE 0 END) as '20', 
sum(CASE WHEN EXTRACT(hour from time_period) = 21 THEN unique_visitors ELSE 0 END) as '21', 
sum(CASE WHEN EXTRACT(hour from time_period) = 22 THEN unique_visitors ELSE 0 END) as '22', 
sum(CASE WHEN EXTRACT(hour from time_period) = 23 THEN unique_visitors ELSE 0 END) as '23' 
from stats 
group by date 
order by date 

輸出

 date 00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 
2013-07-01 22 16 2 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 
2013-07-02 0 0 0 0 30 0 0 0 50 0 0 0 0 0 0 0 15 0 0 0 0 0 0 0 

-Jeff魏斯