Find the 1st matching parent and update it with parent_id in business_table table in SQL Server

Question

I have this business table

ref_ID      name    parent_id 
-----------------------------
ABC-0001    Amb     NULL 
PQR-899     boss    NULL
tgv-632     pick    NULL

I want to update parent_id which is stored in another table parent_customer .

parent_customer table lists a hierarchy of data in which when both ref_id and parent_id are the same means it's the parent of the entire hierarchy.

For example:

4   PQR-899    PQR-899  this is ultimate parent of hierarchy

parent_customer

ID  ref_id     parent_id  
---------------------------
1   ABC-0001   opr-656
2   opr-656    ttK-668
3   ttK-668    ttK-668
4   PQR-899    PQR-899
5   kkk-565    AJY-567  
6   AJY-567    UXO-989
7   UXO-989    tgv-632
8   tgv-632    mnb-784 
9   mnb-784    qwe-525 
10  qwe-525    qwe-525

match_table_CM :

id    main_id
--------------
1     opr-656
2     PQR-899
3     tgv-632
4     mnb-784

You have to first match business table ref_id with parent_customer 's ref_id , and get the parent_id and check if that parent id is in match_table_CM ( main_id ), then update it with business table parent_id . Otherwise find the next parent check with main table. If all not found update it with last parent id.

For example: let's take ABC-0001 from business table, its parent_id is NULL; check with parent_customer table's ref_id column, find the 1st record with parent_id = opr-656 , then check with if that id exists in table match_table_CM ( 1 opr-656 ) - yes - then update business table ( parent_id ) other wise check the next parent_customer hierarchy match parent_id ttK-668 check with match_table ... till you reach the top.(Exit when 1st match found and move to next id from business table )

Answer 1

You can write your update like following.

update t 
set        t.parent_id = pc.parent_id 
from       [yourtble] t 
inner join parent_customer pc  on pc.ref_id = t.ref_id
where      exists 
           ( 
                  select 1 
                  from   match_table_cm 
                  where  main_id= pc.parent_id )

Answer 2

Please try below one. It will be helpful to you.

UPDATE bus
SET bus.parent_id = pc.ID
FROM tbl_buss bus
inner join parent_customer pc on pc.ref_id = bus.ref_id
inner join match_table_CM mt on mt.main_id = pc.parent_id

Thanks, Amit Prajapati

Answer 3

Try this...

UPDATE bt 
SET    bt.parent_id = pc.parent_id 
FROM   businesstable bt 
       INNER JOIN parent_customer pc ON pc.ref_id = bt.ref_id 
       INNER JOIN match_table_cm mt  ON mt.main_id = pc.parent_id 

Output

+------------+------+------------+
|   ref_ID   | name | parent_id  |
+------------+------+------------+
| ABC-0001   | Amb  | opr-656    |
| PQR-899    | boss | PQR-899    |
| tgv-632    | pick | mnb-784    |
+------------+------+------------+

Online Demo: http://rextester.com/FAENX59383