3個表的內部連接給出重復的結果

Question

我有以下3表結構（未提及allcolumns，僅需要）

user_master

user_id（主鍵）

FNAME

雇員

employee_id（主鍵）

user_id（外鍵）

房地產

studexperience_master

exp_id（主鍵）

user_id（外鍵）

我有以下2個mysql查詢，從3個表中獲取數據，同時在1個表中顯示表單display（以下查詢用於搜索結果）。前兩個表正在正常連接但問題是在加入下兩個表時（即員工和studexperience_master）重復獲取數據，如果相同的user_id比結果集中的getttin 3行多3次，這應該只有1行，我試過DISTINCT ALSO FOR SECOND INNER JOIN BUT ISSUE NOT GETTING SOLVE ,HOW THE QUERY SHOULD BE?

$get_work=mysql_query("SELECT DISTINCT wm.work,wm.status FROM user_master um 
INNER JOIN employee emp ON um.user_id =emp.user_id 
INNER JOIN studexperience_master wm 
ON emp.user_id=wm.user_id 
WHERE wm.display='Y' $status_val $company_val $searchkind_val $location_val 
$search_Qualification_val");

---

        SELECT um.user_id,
       um.fname,
       um.lname,
       um.email,
       um.mobile,
       emp.employee_id,
       emp.ecountry,
       emp.estate,
       emp.ecity,
       emp.prefcities,
       emp.ca,
       emp.cs,
       emp.cwa,
       emp.completed,
       emp.persuing
FROM user_master um
INNER JOIN employee emp 
ON um.user_id =emp.user_id
INNER JOIN studexperience_master wm 
ON emp.user_id=wm.user_id
WHERE wm.display='Y' $status_val 
$company_val $searchkind_val $location_val 
$search_Qualification_val

以及where子句值屬於這樣的值

WHERE wm.display='Y' AND status LIKE '%Fresher%' AND efamiliar LIKE '%Tally %' AND work LIKE 'Excise Audit' AND ecountry LIKE 'pune' OR ecity LIKE 'pune' OR estate LIKE 'pune' OR prefcities LIKE 'pune' AND ca REGEXP '%|CA CPT%' OR cs REGEXP '%|CA CPT%' OR cwa REGEXP '%|CA CPT%' OR completed REGEXP '%|CA CPT%' OR persuing REGEXP '%|CA CPT%'

user_master

user_id- 2

fname- monika

mobile- 2147 ......

email- a @ ab

雇員

   >employee_id- 1

    >user_id- 2

    >ecity- Amravati

    >ca- CA IPCC Appeared

    >cs- CS Executive Appeared

    >cwa- CWA Inter Appeared   

studexperience_master

ROW1

exp_id-1

user_id- 2

工作 - 稅務審計

ROW2

exp_id-2

user_id- 2

工作 - 增值稅審計

Answer 1

只需更改您的兩個查詢，如下所示

相反，與加盟emp.user_id與加盟um.user_id原因是PK，應該有獨特的數據。

SELECT DISTINCT wm.work,wm.status  
FROM user_master um  
INNER JOIN employee emp  
ON um.user_id =emp.user_id  
INNER JOIN studexperience_master wm  
ON um.user_id=wm.user_id and wm.display='Y' 

第二個查詢就像

   SELECT um.user_id,
   um.fname,
   um.lname,
   um.email,
   um.mobile,
   emp.employee_id,
   emp.ecountry,
   emp.estate,
   emp.ecity,
   emp.prefcities,
   emp.ca,
   emp.cs,
   emp.cwa,
   emp.completed,
   emp.persuing
FROM user_master um
INNER JOIN employee emp 
ON um.user_id =emp.user_id
INNER JOIN studexperience_master wm 
ON um.user_id=wm.user_id and wm.display='Y'

雖然我無法理解這些變量的含義在where ？ 你的where對我來說很奇怪。

WHERE wm.display='Y' $status_val $company_val $searchkind_val $location_val 
$search_Qualification_val

Answer 2

請嘗試以下查詢：

SELECT distinct um.user_id,
       um.fname,
       um.lname,
       um.email,
       um.mobile,
       emp.employee_id,
       emp.ecountry,
       emp.estate,
       emp.ecity,
       emp.prefcities,
       emp.ca,
       emp.cs,
       emp.cwa,
       emp.completed,
       emp.persuing
FROM user_master um
INNER JOIN employee emp 
ON um.user_id =emp.user_id
INNER JOIN 
(SELECT DISTINCT user_id FROM studexperience_master WHERE <your ALL conditions ON this TABLE>) wm 
ON emp.user_id=wm.user_id
WHERE $status_val 
$company_val $searchkind_val $location_val 
$search_Qualification_val;

Answer 3

你可以試試這樣的東西。 如果學生體驗主表有重復項，那么只需嘗試獲取前一條記錄（根據某些條件，您可以根據需要為此記錄執行過濾器）。

Select * from user_master UM
inner join employee EMP on UM.UserId = EMP.UserId
inner join studexperience_master USM on EMP.UserId = (SELECT  TOP 1 UserId FROM studexperience_master RJK WHERE USM.UserId = RJK.UserId)

如果有任何問題或需要任何幫助，請告訴我。，:)