MYSQL的毗連，左加入，集團解決方案

Question

我有兩個表

1）cawangan_tbl

mysql> select * from cawangan_tbl 
+------------+---------------------------+------------+-------+ 
| IdCawangan | NamaCawangan    | IdParlimen | IdDun | 
+------------+---------------------------+------------+-------+ 
|   3 | Kampung Titi Tinggi Hilir |   1 |  6 | 
|   6 | Kampung Titi Rendah Hilir |   3 |  6 | 
|   7 | Kampung Titi Kiri Hilir |   3 |  6 | 
|   8 | Kampung Titi Kanan Hilir |   3 |  6 | 
+------------+---------------------------+------------+-------+    

2）minit_tbl

select IdMinit,IdDun,IdCawangan,IdParlimen,NoMinit,Status from minit_tbl 
+---------+-------+------------+------------+---------+--------+ 
| IdMinit | IdDun | IdCawangan | IdParlimen | NoMinit | Status | 
+---------+-------+------------+------------+---------+--------+ 
|  14 |  6 |   3 |   3 | 1  | OnTime | 
|  15 |  6 |   3 |   3 | 2  | OnTime | 
|  16 |  6 |   3 |   3 | 4  | Late | 
|  17 |  6 |   7 |   3 | 1  | Late | 
+---------+-------+------------+------------+---------+--------+ 

現在，我的輸出是這樣的：

select C.IdCawangan, 
CONCAT(case when M.NoMinit = 1 then (CONCAT(M.NoMinit,'--> ',M.status)) else 0 end) MonthJan, 
CONCAT(case when M.NoMinit = 2 then (CONCAT(M.NoMinit,'--> ',M.status)) else 0 end) MonthFeb, 
sum(case when M.NoMinit = 3 then M.NoMinit else 0 end) MonthMac, 
sum(case when M.NoMinit = 4 then M.NoMinit else 0 end) MonthApril, 
sum(case when M.NoMinit = 5 then M.NoMinit else 0 end) MonthMei, 
sum(case when M.NoMinit = 6 then M.NoMinit else 0 end) MonthJun 
from cawangan_tbl C left join minit_tbl M 
on M.IdCawangan = C.IdCawangan 
group by C.IdCawangan 

+------------+-------------+----------+----------+------------+----------+----------+ 
| IdCawangan | MonthJan | MonthFeb | MonthMac | MonthApril | MonthMei | MonthJun | 
+------------+-------------+----------+----------+------------+----------+----------+ 
|   3 | 1--> OnTime | 0  |  0 |   4 |  0 |  0 | 
|   6 | 0   | 0  |  0 |   0 |  0 |  0 | 
|   7 | 1--> Late | 0  |  0 |   0 |  0 |  0 | 
|   8 | 0   | 0  |  0 |   0 |  0 |  0 | 
+------------+-------------+----------+----------+------------+----------+----------+

按說，我的輸出會是這樣的MonthFeb：

+------------+-------------+-------------+----------+------------+----------+----------+ 
| IdCawangan | MonthJan | MonthFeb | MonthMac | MonthApril | MonthMei | MonthJun | 
+------------+-------------+-------------+----------+------------+----------+----------+ 
|   3 | 1--> OnTime | 2--> OnTime |  0 |   4 |  0 |  0 | 
|   6 | 0   | 0   |  0 |   0 |  0 |  0 | 
|   7 | 1--> Late | 0   |  0 |   0 |  0 |  0 | 
|   8 | 0   | 0   |  0 |   0 |  0 |  0 | 
+------------+-------------+-------------+----------+------------+----------+----------+  

能

有人點我在正確的代碼如何顯示像MonthJan每個下個月？

Answer 1

在原始查詢中添加了一些案例和聚合函數。

檢查：

select C.IdCawangan, 
coalesce(case when max(case when M.NoMinit = 1 then M.NoMinit else 0 end)>0 then 
    concat(max(case when M.NoMinit = 1 then M.NoMinit else 0 end),'-->',M.status) end,0) MonthJan, 
coalesce(case when max(case when M.NoMinit = 2 then M.NoMinit else 0 end) >0 then 
    concat(max(case when M.NoMinit = 2 then M.NoMinit else 0 end),'-->',M.status) end,0) MonthFeb, 
sum(case when M.NoMinit = 3 then M.NoMinit else 0 end) MonthMac, 
sum(case when M.NoMinit = 4 then M.NoMinit else 0 end) MonthApril, 
sum(case when M.NoMinit = 5 then M.NoMinit else 0 end) MonthMei, 
sum(case when M.NoMinit = 6 then M.NoMinit else 0 end) MonthJun 
from cawangan_tbl C left join minit_tbl M 
on M.IdCawangan = C.IdCawangan 
group by C.IdCawangan; 

希望這有助於:)