[µo°Ý] SQL ¦p¦óLEFT JOIN ¦P¤@­ÓTABLE ¤£¦P±ø¥ó? SQL, LEFT JOIN, SUM

PKKO

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Aªí:
ID,©m¦W
1,ªô¥ý¥Í
2,¶À¥ý¥Í
3,³¯¥ý¥Í

Bªí:
ID,ª÷ÃB,µ²²M»P§_,¤é´Á
1,100,FALSE,2019/1/1
1,100,TRUE,2020/1/1
2,100,FALSE,2019/1/1
2,100,TRUE,2020/1/
3,100,FALSE,2019/1/1

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©m¦W(¥ÎID¤ñ¹ï),ª÷ÃB(¤£ºÞµ²²M»P§_¡Aª½±µ¥Hid¥[Á`),¤é´Á(¥u§ì¨úµ²²M»P§_¬°TRUEªº¤é´Á)
ªô¥ý¥Í,200,2020/1/1
¶À¥ý¥Í,200,2020/1/1
³¯¥ý¥Í,100,NULL

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jcchiang

¦^´_ 1# PKKO

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SELECT a.©m¦W,a.ª÷ÃB,b.¤é´Á
FROM (Select A.©m¦W,sum(b.ª÷ÃB) as ª÷ÃB
from (a inner join B on a.ID=B.ID) group by A.©m¦W  ) as a
LEFT OUTER JOIN (select a.©m¦W,b.¤é´Á  
from a,b
where b.µ²²M»P§_='True' and a.ID=b.ID  ) as b ON a.©m¦W=b.©m¦W

joey0415

¦^´_  joey0415


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sum ©M left join
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¬O¦] ...
PKKO µoªí©ó 2020-1-14 17:09

    ¥ý group by  ©M sum()  ¦A¨â¦¸  left join  (²Ä¤@¦¸¥ý  id¡A²Ä¤G¦¸¥ý±Nªí¤G¬°true  select «á¡A¦A¦ê±µ°_¨Ó¡A¦P¼Ë¤]¬O  id=id)

PKKO

¦^´_ 2# joey0415


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sum ©M left join
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2.¤é´Á¥²¶·¥u±a¤J¦³µ²²M§À´Úªº¤é´Á

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­Yleft join ­Y¥Îid +µ²²M§À´Ú¬°true «h ª÷ÃB·|¿ù»~

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joey0415

¦U¦ì¤j¤j¦n,·Q½Ð±Ð¦p¦ó¤USQL »yªkªº°ÝÃD
Aªí:
ID,©m¦W
1,ªô¥ý¥Í
2,¶À¥ý¥Í
3,³¯¥ý¥Í

Bªí:
ID,ª÷ÃB, ...
PKKO µoªí©ó 2020-1-14 12:54

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ÃöÁä¦r  group by  sum()      left join   on     ¤£·|¤ÓÃø

https://www.1keydata.com/tw/sql/sqlgroupby.html
https://www.1keydata.com/tw/sql/sqlouterjoin.html