Learn how to a build a cloud-first strategyRegister Now

x
?
Solved

UPDATE from a SELECT

Posted on 2006-11-21
1
Medium Priority
?
281 Views
Last Modified: 2008-02-07
Hi,

I want to create T-SQL stored procedure that will do the following task :

I have 2 tables. A and B. A and B have 4 fields in common. The fields are named F1, F2, F3 and F4. B is the reference table that contain an ID (say K1 as the field name) and the 4 fields (Fx). A is the data table that contains both the foreign key K1 and also the fields (Fx). So basically, I can do a select on table A and get by using relatinal data the related value of F1, F2, F3 and F4 using the foreign key of A.K1 and primary key of B.K1. But B is so big (millions records), I want to remove the relational for specific queries that has to be very fast and a so select on one table only (A). So periodically, I want to execute a stored procedure that will take the data from B and put them in A using both a SELECT (to get the related data) and an UPDATE (to update the table A).

Look this pseudo code, I want this in TSQL

ARECORDSTOBEUPDATED = SELECT ALL RECORDS FROM A THAT DO NOT CONTAIN F1 VALUE (this means we did not normalized it yet)

( FOREACH MAINDATAROW IN ARECORDSTOBEUPDATED DO:

  REFERENCEROW =  SELECT TOP 1 FROM B WHERE B.K1 = MAINDATAROW .K1

 UPDATE MAINDATAROW WITH REFERENCEROW DATA (F1, F2, F3, F4)
)

This is quite simple, but I really don't know how to achieve this.

Thanks a lot in advance.
0
Comment
Question by:pmengal
1 Comment
 
LVL 143

Accepted Solution

by:
Guy Hengel [angelIII / a3] earned 1000 total points
ID: 17988120
update a
  SET F1 = B.F1, F2 = B.F2, F3 = B.F3, F4 = B.F4
from A
join B
  on A.K1 = B.K1
 and A.F1 IS NULL
0

Featured Post

Free Tool: Site Down Detector

Helpful to verify reports of your own downtime, or to double check a downed website you are trying to access.

One of a set of tools we are providing to everyone as a way of saying thank you for being a part of the community.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article shows gives you an overview on SQL Server 2016 row level security. You will also get to know the usages of row-level-security and how it works
Microsoft Access has a limit of 255 columns in a single table; SQL Server allows tables with over 255 columns, but reading that data is not necessarily simple.  The final solution for this task involved creating a custom text parser and then reading…
Using examples as well as descriptions, and references to Books Online, show the documentation available for date manipulation functions and by using a select few of these functions, show how date based data can be manipulated with these functions.
This video shows how to set up a shell script to accept a positional parameter when called, pass that to a SQL script, accept the output from the statement back and then manipulate it in the Shell.
Suggested Courses

810 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