Question

I was trying to retrieve value from two tables by joining, but few values in the second columns missing.

eg

valuetable

----------------------
| id |orderid| prodid|
----------------------
|  1 |  NULL |      4|
----------------------
|  1 |     A |      4|
----------------------
|  2 |  NULL |      4|
----------------------
|  2 |  NULL |      3|
----------------------
|  3 |     B |      4|
----------------------
|  3 |     B |      3|
----------------------
|  3 |     B |      5|
----------------------

Nametable

--------------
| id |   Name|
--------------
|  1 |  Apple|
--------------
|  2 |   Ball|
--------------
|  3 |    Cat|
--------------
|  4 |    Dog|
--------------

I have the above two table. I have to retrieve values in the below format.

Query Result

----------------------
| id |   Name|orderid|
----------------------
|  1 |  Apple|  NULL |
----------------------
|  2 |   Ball|  NULL |
----------------------
|  3 |    Cat|     B |
----------------------
|  4 |    Dog|  NULL |
----------------------

I have used the following query

SELECT  nt.id, nt.[Name]
    , MIN(vt.orderid) AS orderid
FROM   Nametable nt  LEFT OUTER JOIN valuetable vt 
ON nt.id = vt.id
WHERE 
    vt.prodid = 3
GROUP BY
    nt.id, nt.[Name]

but missing the | 1 | Apple| NULL | row. How can I retrieve it?
using MSSQL Server 2005

UPDATE

value table doesn’t have id value 1 for prodid=3 but I need a result in the above mentioned way. means if it cannot get id from the valuetable for the corresponding prodid it should still retrieve the id and its name with NULL value as orderid.

Answer 1

Seems you have

WHERE vt.prodid = 3

valuetable does not contain an Apple with prodid = 3

So you should not have in the where but in the join clause:

SELECT  nt.id, nt.[Name]
, MIN(vt.orderid) AS orderid
FROM   Nametable nt  LEFT OUTER JOIN valuetable vt 
ON nt.id = vt.id AND vt.prodid = 3
GROUP BY
  nt.id, nt.[Name]