Question

I need a help with a small query.

Table A:- status and the contents of it are below.

 status_id      status_descrip 
        1          held 
        2          release 
        3          WIP

Table B:- Entry is another table which has some 30 fields. Out of which 2 fields are referring to Table A-> status table. For simplicity i am skipping other fields and jotting down only the fields related with status.

 entry_id        design_status         stress_status
     1                 3                   1
     2                 1                   2
     3                 NULL                2
     4                 3                   3
     5                 NULL                1
     6                 NULL               NULL      
     7                 NULL                2   

I can’t change the structure of Entry to split into 2 tables one as design_status and other as stress_status.

Now i want the entries from entry table replace the status with their descriptions. so the output will be

   entry_id        design_status_descrip         stress_status_descrip
      1                   WIP                          held
      2                   held                         release
      3                   NULL                         release
      4                   WIP                          WIP.
      5                   NULL                         held
      6                   NULL                         NULL
      7                   NULL                         release

Thanks in advance!

EDIT:-

Question is edited with Entries.

Thankyou for all your responses!

and the query finally working for me is,

SELECT     b.entry_id,     design_status_descrip = d.status_descrip,   
  stress_status_descrip = s.status_descrip FROM     entry AS b   
  LEFT OUTER JOIN status AS d     ON b.design_status = d.status_id   
  LEFT OUTER JOIN  status AS s     ON b.stress_status = s.status_id

do let me know, if i can improve this query.

Answer 1

The simplest way would be to join against the status table twice. I’ve used INNER JOIN assuming that the design_status and stress_status columns in your schema have proper constraints. Edited for changed requirements.

DECLARE @status TABLE
(
    status_id INT PRIMARY KEY,
    status_descrip VARCHAR(32) NOT NULL UNIQUE
);

INSERT @status SELECT 1,'held' UNION SELECT 2,'release' UNION SELECT 3,'WIP';

DECLARE @b TABLE
(
    entry_id INT PRIMARY KEY,
    design_status INT,
    stress_status INT
);

INSERT @b SELECT 1,3,1
UNION SELECT 2,1,2
UNION SELECT 3,NULL,2
UNION SELECT 4,3,3
UNION SELECT 5,NULL,1
UNION SELECT 6,NULL,NULL
UNION SELECT 7,NULL,2;

SELECT
    b.entry_id,
    design_status_descrip = d.status_descrip,
    stress_status_descrip = s.status_descrip
FROM
    @b AS b
    LEFT OUTER JOIN @status AS d
    ON b.design_status = d.status_id
    LEFT OUTER JOIN @status AS s
    ON b.stress_status = s.status_id;