SQL與3個表的內部聯接？

Question

我想在視圖中加入3個表格;這裏是情況：

我有一個表格，其中包含申請住在這所大學校園的學生的信息。我有另一張表格，列出了每個學生的大廳首選項（其中3個）。但是，這些偏好中的每一個都只是一個ID號碼，並且ID號在第三個表中有一個對應的名稱（沒有設計這個數據庫......）。

差不多，我有INNER上表連接自己的喜好，他們的信息，結果是一樣的東西......

John Doe | 923423 | Incoming Student | 005 

凡005將是HallID。所以現在我想將HallID與第三個表相匹配，此表中包含HallID和HallName。

那麼好看多了，我想我的結果是這樣......

John Doe | 923423 | Incoming Student | Foley Hall <---(INSTEAD OF 005) 

編輯這裏是我目前有

SELECT 
    s.StudentID, s.FName, 
    s.LName, s.Gender, s.BirthDate, s.Email, 
    r.HallPref1, r.HallPref2, r.HallPref3 
FROM 
    dbo.StudentSignUp AS s 
    INNER JOIN RoomSignUp.dbo.Incoming_Applications_Current AS r 
    ON s.StudentID = r.StudentID 
    INNER JOIN HallData.dbo.Halls AS h 
    ON r.HallPref1 = h.HallID 

Answer 1

你可以做以下的（我猜上表中的字段等等）

SELECT s.studentname 
    , s.studentid 
    , s.studentdesc 
    , h.hallname 
FROM students s 
INNER JOIN hallprefs hp 
    on s.studentid = hp.studentid 
INNER JOIN halls h 
    on hp.hallid = h.hallid 

編輯：根據您的要求爲多廳

你可以這樣做。你剛纔多次加入你的堂表中的每個房間PREF ID：

SELECT  s.StudentID 
    , s.FName 
    , s.LName 
    , s.Gender 
    , s.BirthDate 
    , s.Email 
    , r.HallPref1 
    , h1.hallName as Pref1HallName 
    , r.HallPref2 
    , h2.hallName as Pref2HallName 
    , r.HallPref3 
    , h3.hallName as Pref3HallName 
FROM dbo.StudentSignUp AS s 
INNER JOIN RoomSignUp.dbo.Incoming_Applications_Current AS r 
    ON s.StudentID = r.StudentID 
INNER JOIN HallData.dbo.Halls AS h1 
    ON r.HallPref1 = h1.HallID 
INNER JOIN HallData.dbo.Halls AS h2 
    ON r.HallPref2 = h2.HallID 
INNER JOIN HallData.dbo.Halls AS h3 
    ON r.HallPref3 = h3.HallID 

Answer 2

如果你有相同的ID 3個表我認爲它會是這樣的：

SELECT * FROM table1 a 
JOIN table2 b ON a.ID = b.ID 
JOIN table3 c ON a.ID = c.ID 

只需將*替換爲您想要從表中獲得的內容即可。

Answer 3

您只需要第二個內部聯接，即將您現在的ID Number鏈接到第三個表的ID Number。此後，由Hall Name瞧:)

更換 ID Number

Answer 4

SELECT column_Name1,column_name2,...... 
    From tbl_name1,tbl_name2,tbl_name3 
    where tbl_name1.column_name = tbl_name2.column_name 
    and tbl_name2.column_name = tbl_name3.column_name 

Answer 5

這是正確的查詢加入3表相同的ID **

select a.empname,a.empsalary,b.workstatus,b.bonus,c.dateofbirth from employee a, Report b,birth c where a.empid=b.empid and a.empid=c.empid and b.empid='103'; 

員工第一個表。 報告第二張表。 誕生第三個表

Answer 6

select empid,empname,managename,[Management ],cityname 
from employees inner join Managment 
on employees.manageid = Managment.ManageId  
inner join CITY on employees.Cityid=CITY.CityId 


id name managename managment cityname 
---------------------------------------- 
1 islam hamza  it  cairo 

Answer 7

SELECT table1.col,table2.col,table3.col 
FROM table1 
INNER JOIN 
(table2 INNER JOIN table3 
ON table3.id=table2.id) 
ON table1.id(f-key)=table2.id 
AND //add any additional filters HERE 

Answer 8

SELECT * 
FROM 
    PersonAddress a, 
    Person b, 
    PersonAdmin c 
WHERE a.addressid LIKE '97%' 
    AND b.lastname LIKE 'test%' 
    AND b.genderid IS NOT NULL 
    AND a.partyid = c.partyid 
    AND b.partyid = c.partyid; 

Answer 9

SELECT 
A.P_NAME AS [INDIVIDUAL NAME],B.F_DETAIL AS [INDIVIDUAL FEATURE],C.PL_PLACE AS [INDIVIDUAL LOCATION] 
FROM 
[dbo].[PEOPLE] A 
INNER JOIN 
[dbo].[FEATURE] B ON A.P_FEATURE = B.F_ID 
INNER JOIN 
[dbo].[PEOPLE_LOCATION] C ON A.P_LOCATION = C.PL_ID 

Answer 10

此查詢會爲你

Select b.id as 'id', u.id as 'freelancer_id', u.name as 
'free_lancer_name', p.user_id as 'project_owner', b.price as 
'bid_price', b.number_of_days as 'days' from User u, Project p, Bid b 
where b.user_id = u.id and b.project_id = p.id