Datatable.column expression to match Select Sum From Where

[ktab]

Hello all

I was wondering how i could pass the following SLQ function to my datatable:

Select sum(Quantity) from Purchases where transaction_mode=1

Thank you

[kvprajapati]

@ktab I'm unable to understand your question. Please elaborate your question. If you want to execute a query then you need to use ADO.NET provider classes.

[ktab]

I know how to do it in ado. I was just wondering how this can be done in a datatable.
In ADO, i just connect an execute a command with commandtext like Select sum(Quantity) from Purchases where transaction_mode=1 and capture result in a string variable.

So, what I ask, is how table.columns(int).expression(expresion_string) works, if I may use .expression property to return result of query, if this is possible.
And if this is possible, how can I simulate the above SQL string into .expression

[ktab]

Almost done this I guess...
It's the .compute that I need. So it must be like datatable(tablename).compute("sum(quantity)", "transaction_mode=1")
Haven't tried this yet, but I'm almost sure this is it.