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Posted by Erland Sommarskog on 08/13/07 12:26
Clive Swan (cliveswan@yahoo.co.uk) writes:
> My GIS software has a tool to count the number of points within a grid.
> This is fine for small recordset, when you get into the tens thousands
> it becomes unfriendly.
>
> It must be possible (more efficent??) to do a select statement from
> the two tables and insert the result into a column??
>
> Table Property has thousands of records that fall within each record
> of Table Ward.
>
> Expect the SQL would be
>
> SELECT [Property].BedRmNumber FROM [Ward].LA
> WHERE [Property].LA = [Ward].LA
>
> Surely this would need a loop.
Loops are rarely effective.
It is not very clear from your post what you want to do. You talk
about selecting a count, but the SELECT statement you have lists a
column.
Doing a very wild guess, this may be what you are looking for:
SELECT P.BedRmNumber, COUNT(*)
FROM Ward W
JOIN Property P ON W.LA = P.LA
GROUP BY P.BedRmNumber
The usual recommendation for these type of questions is that you post:
o CREATE TABLE statements for your tables.
o INSERT statements with sample data.
o The desired result given the sample.
The less you include of this, the more guesswork you will get in
response.
--
Erland Sommarskog, SQL Server MVP, esquel@sommarskog.se
Books Online for SQL Server 2005 at
http://www.microsoft.com/technet/prodtechnol/sql/2005/downloads/books.mspx
Books Online for SQL Server 2000 at
http://www.microsoft.com/sql/prodinfo/previousversions/books.mspx
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