联袂汇总到非汇总数据

Question

我有以下两个表格

Key   |Clicks |Impressions| 
-------------+-------+-----------+ 
USA-SIM-CARDS|55667 |544343  | 


    Key   |Conversions |State| 
-----------------+------------+------ 
USA-SIM-CARDS | 456  |NJ 
USA-SIM-CARDS |2   |FL 
USA-SIM-CARDS |56   |AK 
USA-SIM-CARDS |23   |MY 

我想下面的输出

 Key   |Conversions |Clicks |Impressions| 
-----------------+------------+- -----+-----------+ 
USA-SIM-CARDS | 537  | 55667|544343 

是否有可能通过加入做到这一点还是我将不得不诉诸循环数据？

非常感谢。

Answer 1

尝试：

SELECT f.key, f.clicks, f.impressions, sum(s.Conversions) As Conversions 
FROM first_table f 
JOIN second_table s 
-- also LEFT JOIN can be used if you want to get rows from F 
-- even when there are no any corresponding rows in S 
ON f.Key = s.Key 
Group By f.key, f.clicks, f.impressions 

演示：http://sqlfiddle.com/#!15/7864e/2