Solved

Update master record with rowcount

Posted on 2010-09-23
5
347 Views
Last Modified: 2012-06-27
(Optional Read) Business Objective:  Count the number of roommates living with the primary tenant/resident and update a field on the resident record.

(Optional Read) Background:  FYI, I’m comfortable with SQL select and update statements.   I have minimal experience with cursors, stored procedures etc.   (Of course) I use a test DB prior to applying to production environment.

(Must Read) The Primary Question for Experts:
Assuming the SQL statement provide below is on the right track, how should I modify the SQL statement to:
o      Accumulate/Count the quantity of roommates for each of the 10000 tenant records
o      Update the sfields9 field for each of the 10000 tenant records
I think I need to use a cursor (not confident).
Of course I will award points appropriately if my general direction is wrong and Expert(s) provide redirection.

SQL Statement: The statement below successfully updates the Tenant.sfields9 record with quantity of individuals living with the specified tenant “49546”.  (Note the “49546” filters the select and update to one tenant/resident.)   The successful solution should run without the where clause limiting to an individual tenant.  It should run for all tenants, subtotaling the quantity of roommates for each tenant, and updating the sfields9 field with said subtotal.

select p.Sfirstname + ' ' + p.ulastname, t.hmyperson
From person p left outer join room r on p.hmy = r.hmyperson
left outer join tenant t on t.hmyperson = r.hmytenant
where
p.hmy  in (49546) or R.hmytenant in (49546)
update tenant set sfields9 = (@@rowcount + 1)  where hmyperson = 49546

(Optional Read) Table.Field Details:
1.      Tenant.sfields9 = “Tenant” Table and  “sfields9” field holds the quantity of individuals living in apartment.
2.      “Room” table contains roommates id (xref to “Tenant” table)
3.      “Person” table contains name, address, etc for both the tenant and room tables

Experts-Exchange---Update-Primar.doc
0
Comment
Question by:LFreehauf
  • 3
  • 2
5 Comments
 
LVL 142

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 500 total points
ID: 33744822
this should do;
update x

  set sfields9 = 1 + ( 

    select count(*)

      from  person p 

      left outer join room r 

       on p.hmy = r.hmyperson

      left outer join tenant t 

      on t.hmyperson = r.hmytenant

    where p.hmy =  x.hmytenant 

       or R.hmytenant = x.hmytenant 

  )  

 from tenant x

Open in new window

0
 

Author Comment

by:LFreehauf
ID: 33745095
Theory Looks correct.   However, Cut and paste created an error;  I'm happy to modify and further test after this "unexpected meeting".  Thanks for the fast response.
0
 
LVL 142

Expert Comment

by:Guy Hengel [angelIII / a3]
ID: 33746364
what error do you get?
0
 

Author Comment

by:LFreehauf
ID: 33746478
update x
It works!  Thanks.  
I had to change x.hmytenant to x.hmyperson in the where clause.  It updated (successful & accurate) on two tenant records.  Thanks again.  I appreciate it.

set sfields9 = (
    select count(*)
      from  person p
      left outer join room r
       on p.hmy = r.hmyperson
      left outer join tenant t
      on t.hmyperson = r.hmytenant
    where p.hmy =  x.hmyperson
       or R.hmytenant = x.hmyperson
  )  
 from tenant x where x.scode in ('t0036179', 't0003407')
0
 

Author Closing Comment

by:LFreehauf
ID: 33746493
Very good.  Very fast.  Expert follow up when I indicated a problem with exact syntax.  
0

Featured Post

What Should I Do With This Threat Intelligence?

Are you wondering if you actually need threat intelligence? The answer is yes. We explain the basics for creating useful threat intelligence.

Join & Write a Comment

Suggested Solutions

When you hear the word proxy, you may become apprehensive. This article will help you to understand Proxy and when it is useful. Let's talk Proxy for SQL Server. (Not in terms of Internet access.) Typically, you'll run into this type of problem w…
Ever needed a SQL 2008 Database replicated/mirrored/log shipped on another server but you can't take the downtime inflicted by initial snapshot or disconnect while T-logs are restored or mirror applied? You can use SQL Server Initialize from Backup…
Via a live example, show how to set up a backup for SQL Server using a Maintenance Plan and how to schedule the job into SQL Server Agent.
Viewers will learn how to use the SELECT statement in SQL to return specific rows and columns, with various degrees of sorting and limits in place.

746 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

13 Experts available now in Live!

Get 1:1 Help Now