SELECT data from DataSet tables

[=?Utf-8?B?RnJhbmsgVXJheQ==?=]

Hi all

I have a DataSet with 2 tables.
Now I want to select data like a INNER JOIN from these tables.

In SQL Syntax I would write:
SELECT *
FROM table1 t1
INNER JOIN table2 t2
ON t1.f1 = t2.f1
WHERE t2.xy = 'search'

How do I select data like this from a DataSet ??
Or how else can I select data from a DataSet
when I want to get a combination of two or
more tables ??

Thanks for any comments

Best regards
Frank

[Marc Gravell]

Re: SELECT data from DataSet tables

Well, in .NET 3.5 you could probably use LINQ-to-objects to do this as a
join directly, but it looks like you should really be looking via the
DataRelations, where you have a DataRelation linking the two "f1"s. Then
you can use GetParentRow(re lation) or GetChildRows(re lation) to do the
navigation.

Does that help at all?

Marc

[=?Utf-8?B?RnJhbmsgVXJheQ==?=]

Re: SELECT data from DataSet tables

Hi Marc

Thanks for your answer.

I will have to try with GetParentRow/GetChildRow
I did never try with this.

But I ab wondering how other people work with
complex data structures in Datasets ...

Best regards
Frank

"Marc Gravell" wrote:

Well, in .NET 3.5 you could probably use LINQ-to-objects to do this as a
join directly, but it looks like you should really be looking via the
DataRelations, where you have a DataRelation linking the two "f1"s. Then
you can use GetParentRow(re lation) or GetChildRows(re lation) to do the
navigation.
>
Does that help at all?
>
Marc
>

[Marc Gravell]

Re: SELECT data from DataSet tables

I've wondered that myself ;-p

(I'm not a big user of datasets, so I can't answer it, I'm afraid)

Marc

[=?Utf-8?B?RnJhbmsgVXJheQ==?=]

Re: SELECT data from DataSet tables

:-)))

Me too, I used to build online apps with
DataReader's.
But now I have to build a application with
offline (xml file) modus ...

Thanks anyway
Frank



"Marc Gravell" wrote:

I've wondered that myself ;-p
>
(I'm not a big user of datasets, so I can't answer it, I'm afraid)
>
Marc
>

[Tim Jarvis]

Re: SELECT data from DataSet tables

Frank Uray wrote:

Me too, I used to build online apps with
DataReader's.
But now I have to build a application with
offline (xml file) modus ...

Hi Frank,

If you have the option, push very hard to be able to use Linq for
DataSets (.NET 3.5) I guarantee that you will never want to navigate
datasets (or for that matter raw XML) any other way...

DataTable orders = ds.Tables["SalesOrderHead er"];
DataTable orderLines = ds.Tables["SalesOrderDeta il"];

var ordersQuery = orders.AsEnumer able();
var orderLinesQuery = orderLines.AsEn umerable();

var query = from o in ordersQuery
join ol in orderLinesQuery
on o.Field<int>("S alesOrderID") equals
ol.Field<int>(" SalesOrderID")
where o.Field<bool>(" OnlineOrderFlag ") == true &&
o.Field<DateTim e>("OrderDate") .Month == 8
select new { SalesOrderID = o.Field<int>("S alesOrderID"),
SalesOrderDetai lID =
ol.Field<int>(" SalesOrderDetai lID"),
OrderDate = o.Field<DateTim e>("OrderDate") ,
ProductID = ol.Field<int>(" ProductID") };


Cheers Tim.

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