How to SELECT FROM In-Memory dataset in C# .NET?

28 Apr 2006 12:44 PM

BillJohnson4

Experts:

I have built an in-memory dataset by parsing a flat file so that I can
display the contents onto a datagrid.

The Microsoft C# .NET System.Data.DataTable.Select() method allows me
to select all rows that meet certain criteria (just like "WHERE") and
to sort them (just like "ORDER BY").

I want to perform more analysis on this in-memory dataset such as
SUM(), COUNT(*), MIN(), MAX() and possibly even JOIN.

There has to be a way to do SQL commands 100% in-memory without writing
this dataset to a database server. We already have the data in a
dataset in-memory. How can we then use the power of SQL or C# to
process the data further?

Thank you.

28 Apr 2006 1:21 PM

Omnibuzz

I think you have a compute() function for that.

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"BillJohns***@gmail.com" wrote:

> Experts:
>
> I have built an in-memory dataset by parsing a flat file so that I can
> display the contents onto a datagrid.
>
> The Microsoft C# .NET System.Data.DataTable.Select() method allows me
> to select all rows that meet certain criteria (just like "WHERE") and
> to sort them (just like "ORDER BY").
>
> I want to perform more analysis on this in-memory dataset such as
> SUM(), COUNT(*), MIN(), MAX() and possibly even JOIN.
>
> There has to be a way to do SQL commands 100% in-memory without writing
> this dataset to a database server. We already have the data in a
> dataset in-memory. How can we then use the power of SQL or C# to
> process the data further?
>
> Thank you.
>
>

28 Apr 2006 2:16 PM

Stoitcho Goutsev (100)

Bill,

> The Microsoft C# .NET System.Data.DataTable.Select() method allows me
> to select all rows that meet certain criteria (just like "WHERE") and
> to sort them (just like "ORDER BY").
>
> I want to perform more analysis on this in-memory dataset such as
> SUM(), COUNT(*), MIN(), MAX() and possibly even JOIN.

According MSDN all this is supported by the select methods. For more details
see:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemdatadatacolumnclassexpressiontopic.asp

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Stoitcho Goutsev (100)

28 Apr 2006 4:08 PM

BillJohnson4

Stoicho:

Thank you for the link; however, it still does not answer how I can
SUM() across all rows.

I would like to create a view, a column, whatever to SUM() or AVG() or
MIN() or MAX() across all rows of a table in memory.

Any clues or hints?