Join Tables in DataSet

  • Thread starter Thread starter Kai =?iso-8859-1?Q?Br=E4utigam?=
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K

Kai =?iso-8859-1?Q?Br=E4utigam?=

Hi,

is there any way to join two tables in a DataSet? What I need is just like
a JOIN with two tables in a real Database like:

SELECT cu.CustomerID, or.OrdersID
FROM Customers cu, Orders or
WHERE cu.CustomerID = or.CustomerID

or

SELECT cu.CustomerID, or.OrdersID
FROM Customers cu
INNER JOIN Orders or
ON cu.CustomerID = or.CustomerID

I've found the QueryADataSet from Peersoft, which works fine as far as I
can see. Anyone got some experiences with that library?

Maybe any other ideas to solve that problem?

Thanks,
- Kai
 
Hi Jignesh,
Joining tables in DataSet
Use DataSet.Relations
Click to expand...

Sounds good, but could you be a bit more specific?
Maybe a short example?

Thanks in advance,
- Kai
 
Kai,

I'm the developer from Peersoft who built the QueryADataset assembly. As
this is a brand new product, I don't have any references yet. However, there
are several users actively using the product, mostly for displaying web
content from cached Datasets.

If you are more comfortable working with SQL than writing ADO code, then the
QueryADataset product is a good investment.

Feel free to e-mail me if you have any comments or questions.

Thanks
Adrian Moore
http://www.queryadataset.com


----- Original Message -----
From: "Kai Bräutigam" <[email protected]>
Newsgroups: microsoft.public.dotnet.framework.adonet
Sent: Tuesday, August 09, 2005 1:16 AM
Subject: Join Tables in DataSet
 
Hi Miha,
Why do you need to join them?
Just for displaying data?
Click to expand...

no. it's not just for displaying. Mostly I need to work with the data. It's
a web-application with hundreds, maybe thousands of joins I need to do each
request. So I decided to use a DataSet, because I realized regular
SQL-Statements(StoredProcedures) directly to the database are too slow. And
now I'm looking for a fast!!! solution to do JOIN-statements with the
DataSet.

- Kai
 
Hi Kai,

Actually, database join statements are normally faster if they are properly
set (indexes).
Perhaps you hae a problem in database structure?
 
Hi Miha,
Actually, database join statements are normally faster if they are properly
set (indexes).
Perhaps you hae a problem in database structure?
Click to expand...

I know about indexes and how to set them for fast queries. So my problem is
not the database. As you said, normally they are faster, but they aren't in
this special case.

So I need to work with the DataSet and if you have an idea about joining
the tables inside, just let me know... :-)

- Kai
 
Hi Kai,

Kai Bräutigam said:
Hi Miha,


I know about indexes and how to set them for fast queries. So my problem
is
not the database. As you said, normally they are faster, but they aren't
in
this special case.
Click to expand...

Ok, if you say :-)
So I need to work with the DataSet and if you have an idea about joining
the tables inside, just let me know... :-)
Click to expand...

Try one of two articles on the top if they help you:
http://support.microsoft.com/search/default.aspx?catalog=LCID=1033&query=join+dataset
 
Kai,

The join algorithms mentioned in these articles are not optimized and
perform poorly with large data tables. Also, they only provide the
algorithm INNER join, and not LEFT or RIGHT join.

Ad.

Miha Markic said:
Hi Kai,

Kai Bräutigam said:
Hi Miha,


I know about indexes and how to set them for fast queries. So my problem
is
not the database. As you said, normally they are faster, but they aren't
in
this special case.
Click to expand...

Ok, if you say :-)
So I need to work with the DataSet and if you have an idea about joining
the tables inside, just let me know... :-)
Click to expand...

Try one of two articles on the top if they help you:
http://support.microsoft.com/search/default.aspx?catalog=LCID=1033&query=join+dataset

--
Miha Markic [MVP C#] - RightHand .NET consulting & development
www.rthand.com
Blog: http://cs.rthand.com/blogs/blog_with_righthand/
SLODUG - Slovene Developer Users Group www.codezone-si.info
- Kai
Click to expand...
Click to expand...
 
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