SQL使用where子句連接多個表

Question

我想寫一條sql語句：

Select * FROM table1
inner join table2 AS t2
  ON 
inner join table3 AS t3
  ON
inner join table4 AS t4
  ON
Where FK_Client_ID = 4

所有表都有相同的客戶端ID。 因此，不確定在ON上做什么。

是否會像ON t2.FK_Client_ID = ......那樣不確定。

因此，我只希望來自那些具有FK_Client_ID的表的所有數據。

Answer 1

嘗試這個

Select * FROM table1 t1
inner join table2 AS t2
  ON t2.FK_Client_ID = t1.FK_Client_ID
inner join table3 AS t3
  ON t3.FK_Client_ID = t1.FK_Client_ID
inner join table4 AS t4
  ON t4.FK_Client_ID = t1.FK_Client_ID
Where t1.FK_Client_ID = 4

Answer 2

如果您的外地名稱是"FK_Client_ID"並且表1中的主鍵是"Client_ID"

Select * FROM table1
inner join table2 AS t2
  ON  t2.FK_Client_ID = table1.Client_ID
inner join table3 AS t3
  ON  t3.FK_Client_ID = table1.Client_ID
inner join table4 AS t4
  ON  t4.FK_Client_ID = table1.Client_ID
Where table1.Client_ID = 4

由於您正在使用內部聯接，因此無論您將它們與table1還是其他任何一個table1

Answer 3

Select * FROM table1 t1 inner join table2 t2
     ON t1.FK_Client_ID = t2.FK_Client_ID 
        inner join table3 t3
     ON t1.FK_Client_ID = t3.FK_Client_ID
         inner join table4 t4
     ON t1.FK_Client_ID = t4.FK_Client_ID
 Where t1.FK_Client_ID = 4

Answer 4

Select *,
     (Select FK_Client_ID from table2 where FK_Client_ID = t1.FK_Client_ID  )As TID1,
     (Select FK_Client_ID from table3 where FK_Client_ID = t1.FK_Client_ID  )As TID2,
     (Select FK_Client_ID from table4 where FK_Client_ID = t1.FK_Client_ID  )As TID3 
FROM table1 t1