Question

I need to retrieve ListingId from the below table based on the search condition. Kindly help the best way to retrive the query for the conditions below

Note : ListingId can have any number of ExtrafieldId, So Searching ListingId is based on the dynamic ExtrafieldId

If (ExtrafieldId = 1 and Value = 1) => OUTPUT - 20, 22
If (ExtrafieldId = 1 and Value = 1) and (ExtrafieldId = 2 and Value = 7) => OUTPUT - 21
If (ExtrafieldId =4and Value = 1999) => OUTPUT - 20, 21, 23

and so on…

ListingId   ExtraFieldId    Value      
20  1   1      
20  2   4      
20  3          
20  4   1990       
21  1   2      
21  2   7      
21  3          
21  4   1990       
22  1   1      
22  2   4      
22  3          
22  4   2000       
23  1   NULL       
23  2   NULL       
23  4   1999    

Answer 1

SELECT
      t1.ListingID
FROM 
      TableX AS t1 

  JOIN                                --- 2nd JOIN
      TableX AS t2
    ON 
      t2.ListingID = t1.ListingID 

  JOIN                                --- 3rd JOIN
      TableX AS t3
    ON 
      t3.ListingID = t1.ListingID 

WHERE 
      (t1.ExtraFieldID, t1.Value) = (@ExtraFieldID_search1, @Value_search1)

                        --- 2nd condition
  AND 
      (t2.ExtraFieldID, t2.Value) = (@ExtraFieldID_search2, @Value_search2)

                        --- 3rd condition
  AND 
      (t3.ExtraFieldID, t3.Value) = (@ExtraFieldID_search3, @Value_search3)

If you need 3 conditions, you’ll need to join the table to itself one more time (so 3 times in total)