<mtczx232@yahoo.com> wrote in message
news:1135803746.774985.302860@o13g2000cwo.googlegroups.com...
> it seem that data table and Expression field have a lot of Laks, it is
> true?
>
> the DataTable is powerfull of Memory relation data that bind to
> controls.
> so i can load data from remote service and manipulate it and after i
> send update to remote service.
>
> But, when i need to make standart operation that with SQL system is
> simple,
> with Datatable it's impossible.
>
> for example think about Accounting records. i load record from remote.
> and thaen
> user chnge Movement and add some. now (before we update the remote
> server),
> how i can put on the screen balance? by loop over all rows and grouping
> it manually!!
> instead write Group by!!??
>
> [in vb6 i remember the Data Environment that allow grouping!!]
>
> have some Project that extend DataTable abilities?
>
> also with DataColumn.Expression have a Lacke of many simple function.
> like Round, have a way to extend it?
>

<mtczx232@yahoo.com> wrote in message
news:1135803746.774985.302860@o13g2000cwo.googlegroups.com...
> it seem that data table and Expression field have a lot of Laks, it is
> true?
>
> the DataTable is powerfull of Memory relation data that bind to
> controls.
> so i can load data from remote service and manipulate it and after i
> send update to remote service.
>
> But, when i need to make standart operation that with SQL system is
> simple,
> with Datatable it's impossible.
>
> for example think about Accounting records. i load record from remote.
> and thaen
> user chnge Movement and add some. now (before we update the remote
> server),
> how i can put on the screen balance? by loop over all rows and grouping
> it manually!!
> instead write Group by!!??
>
> [in vb6 i remember the Data Environment that allow grouping!!]
>
> have some Project that extend DataTable abilities?
>
> also with DataColumn.Expression have a Lacke of many simple function.
> like Round, have a way to extend it?
>

>>>You are completely correct if you expected the DataTable to be an in memory
>>>database.

>>>it is not this, and it is not meant to be. It has some functionality so

>>>Robbe Morris [C# MVP]
>>The DataTable .Select method does support "some"
>>aggregate functions like SUM and AVG. Another
>>parameter exists for ORDER BY.

> Marina
>>>>You are completely correct if you expected the DataTable to be an in
>>>>memory
>>>>database.
>
> 1.
> we not have discuss about what microsoft think about Datatable, we
> discuss about developers needs.
>

<mtczx232@yahoo.com> wrote in message
news:1135844158.226860.80780@g47g2000cwa.googlegroups.com...
> Marina
>>>>You are completely correct if you expected the DataTable to be an in
>>>>memory
>>>>database.
>
> 1.
> we not have discuss about what microsoft think about Datatable, we
> discuss about
> developers needs.
>
> so, when i use with remote Database, and i use with Datatable as memory
> snapshots of data. it's only modest wish that this table support
> grouping and other expresion function
> like a SQL or Excel. if i need for those simple thing, to go to
> Database, we lost the
> power of DataTable as it can be.
>
> 2.
> I read some document, how join table by looping and so on, but my wish
> is, that someone Make this project like we need. So my Q is, if
> somebody hear about?
>
> 3.
>>>>it is not this, and it is not meant to be. It has some functionality so
> that you can perform operations on snapshots of data that you retrieved
> from
> the database.
>
> I not agree with you, the DataTable is like a Memory Database it's
> contain constrains
> and schema and relations. So Datatable is true Database according the
> Data Definition
> (DD), so why we not expect also Data Manipulation (DM)
>
> 4.
> I know about Memory Database like SharpHSQL project. but i think, that
> not
> have built in binding to Controls, so after eache change on DB, we need
> make a Fill.
> and alse, not have Mathod to save all change on remote DB like
> Datatable do.
>
>
> +++++++++++++++++++++++++++++++++
>>>>Robbe Morris [C# MVP]
>>>The DataTable .Select method does support "some"
>>>aggregate functions like SUM and AVG. Another
>>>parameter exists for ORDER BY.
>
> 1.
> i know about powerfull of Order BY and SELECT. but that is what i'm
> say!!
> Datatable have strong engine, and i expect to add to it some more
> essential function.
> 2.
> SUM and AVG without WHERE is very poor for developers.
>

<mtczx232@yahoo.com> wrote in message
news:1135935281.335599.281820@g43g2000cwa.googlegroups.com...
> Select not include functions(like Round) and Aggragate function.
> Grouping and so on.
> I already Explain my Opinion above. that Developer need tools to do
> Grouping and Aggregate on the Datatable rather then on DB itself.
> if this essential thing is not yet conventional i ready to give you
> more
> examples that convice you.
>
> Now my friend told me about DataWindow.Net from Sybase, i not sure
> about this product, but this is Example for my Opinion, that Dataset
> must includ set of tools for Grouping and Aggregate, like we used
> in DataEnvironment (VB6) and if i remember correct also
> on DataModel in Delphi.
>

> I not agree with you, the DataTable is like a Memory Database it's
> contain constrains
> and schema and relations. So Datatable is true Database according the
> Data Definition
> (DD), so why we not expect also Data Manipulation (DM)

<mtczx232@yahoo.com> wrote in message
news:1135803746.774985.302860@o13g2000cwo.googlegroups.com...
> it seem that data table and Expression field have a lot of Laks, it is
> true?
>
> the DataTable is powerfull of Memory relation data that bind to
> controls.
> so i can load data from remote service and manipulate it and after i
> send update to remote service.
>
> But, when i need to make standart operation that with SQL system is
> simple,
> with Datatable it's impossible.
>
> for example think about Accounting records. i load record from remote.
> and thaen
> user chnge Movement and add some. now (before we update the remote
> server),
> how i can put on the screen balance? by loop over all rows and grouping
> it manually!!
> instead write Group by!!??
>
> [in vb6 i remember the Data Environment that allow grouping!!]
>
> have some Project that extend DataTable abilities?
>
> also with DataColumn.Expression have a Lacke of many simple function.
> like Round, have a way to extend it?
>

"john smith" <john@smith.com> wrote in message
news:e0ogozcDGHA.984@tk2msftngp13.phx.gbl...
>> I not agree with you, the DataTable is like a Memory Database it's
>> contain constrains
>> and schema and relations. So Datatable is true Database according the
>> Data Definition
>> (DD), so why we not expect also Data Manipulation (DM)
>
> Wheter you agree or not with Marina, DataTables/DataSets aren't like a
> true, complete in-memory database (there is no database engine of any
> kind - it's not even remotely similar). It's just a in-memory "snapshot"
> of data, and you can't expect it to be much more than that. You seem to be
> confusing the fact it's a *disconnected* dataset (or table) for it's a
> full-blown DB engine with everything and a kitchen sink built-in. You can
> still request your data like before... But working with disconnected data
> like that is very different, and perhaps you have to adapt to the new way
> of doing things.
>
> To me it sounds like you're using the wrong thing altogether. Perhaps you
> should be using sprocs (or parameterized queries; with your "data
> manipulation" in the queries like you want) with DataReaders to get to
> your data/results. Then perhaps "map" to a set of Business Objects using a
> Data Access Layer (a class methods to abstract/encapsulate your SQL work
> and such, and then return the data you want). And it seems to me that
> those simple math operations (and other things like formatting) could
> easily be done by a few methods in a small class in a few minutes - I
> completely fail to see the big problem here... Sounds more of an
> architecture/design problem than anything to me.
>