-4
我有這樣的SQL請求:加入三代表在MySQL
SELECT c.id
,c.NAME
,c.email
,d.NAME AS dealer
,count(ur.id) AS users
,count(v.id) AS vehicules
FROM company c
JOIN dealer d ON d.id = c.dealer_fk
JOIN vehicule v ON v.company_fk = c.id
JOIN users ur ON ur.company_fk = c.id
GROUP BY c.id
我在database..but一個用戶的結果給了8個用戶..我不知道爲什麼??。
請參閱http://meta.stackoverflow.com/questions/333952/why-should-i-provide-an-mcve-for-what-seems-to-me-to-be-a-very-simple- sql-query – Strawberry
yess..i擁有一對多 –
@stackAcountstackAcount任何時候,如果您有1對多關係的數據的1部分將被複製爲每個衆多的數據。 –