如何在SQL上连接两个表 [英] How do I join two tables on SQL

问题描述

我有两个表，一个包含用户数据（kings），另一个表包含他们引用的那些（king_referrer）加入网站。



我想表明每个用户推荐了多少人，这个有效：

I have two tables, one contains the user data(kings), the other table contains those they referred(king_referrer) to join the website.

I want to show how many people each user has referred, this works:

SELECT `referrer_id`, COUNT(referrer_id) 
FROM (SELECT DISTINCT ref_email, referrer_id FROM king_referrer)  
AS result_one 
GROUP BY referrer_id 
ORDER BY COUNT(referrer_id) DESC

但是现在，我想从用户数据表（国王）中获取他们的全名。 />


我尝试使用它，但它不起作用，我收到一个错误说（

But now, I want to get their full name from the user data table (kings).

I tried using this, but it doesn't work, i get an error saying (

Unknown column 'king_referrer.referrer_id' in 'on clause'): 

SELECT referrer_id, COUNT(referrer_id) 
FROM (SELECT DISTINCT ref_email, referrer_id FROM king_referrer)  
AS result_one
LEFT JOIN kings ON king_referrer.referrer_id=kings.user_id
GROUP BY referrer_id 
ORDER BY COUNT(referrer_id) DESC;

请帮忙。谢谢。



我尝试过：



SELECT referrer_id， COUNT（referrer_id）

FROM（SELECT DISTINCT ref_email，referrer_id FROM king_referrer）

AS result_one

LEFT JOIN kings ON king_referrer.referrer_id = kings。 user_id

GROUP BY referrer_id

ORDER BY COUNT（referrer_id）DESC;

Please help. Thank you.

What I have tried:

SELECT referrer_id, COUNT(referrer_id)
FROM (SELECT DISTINCT ref_email, referrer_id FROM king_referrer)
AS result_one
LEFT JOIN kings ON king_referrer.referrer_id=kings.user_id
GROUP BY referrer_id
ORDER BY COUNT(referrer_id) DESC;

推荐答案

检查这个...

Hi,

Check this...

SELECT referrer_id, COUNT(referrer_id) 
FROM (SELECT DISTINCT ref_email, referrer_id FROM king_referrer
LEFT JOIN kings ON king_referrer.referrer_id=kings.user_id
) 
AS result_one
GROUP BY referrer_id 
ORDER BY COUNT(referrer_id) DESC;

希望这会对你有所帮助。



干杯

Hope this will help you.

Cheers

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