Expression Column - DataRelation - Filtering

[Jo?o P. Bragan?a]

I would like to add an expression column that gets the count of child
rows that match a criteria:

Expression = "COUNT(Child(Inventory2Sales).Invoiced = false)";

However I get a SyntaxErrorException: "Syntax error in aggregate
argument: Expecting a single column argument with possible 'Child'
qualifier."

What is the proper syntax for this? Is it even possible?

 

[Lloyd Dupont]

something like

SELECT COUNT(*) As NotInvoice FROM MyTable WHERE Invoiced = false

 

[William Ryan eMVP]

That definitely won't work. you can use
DataTable.Compute(COUNT(CHILD(Inventory2Sales), "Invoiced = false") for a
one column issue. The filter condition is what's blowing up on this one.

 

[Jo?o P. Bragan?a]

So in other words it's impossible to have a data column with the
computed value already in it... is microsoft going to improve this
functionality in a later release of .net?

 

[William Ryan eMVP]

No, not at all.

So in other words it's impossible to have a data column with the
computed value already in it... is microsoft going to improve this
functionality in a later release of .net?

"William Ryan eMVP" <[email protected]> wrote in message

 

[William Ryan eMVP]

Sorry about that I didn't post the reply. I think the answer is to use the
straight expression syntax:
Expression = "COUNT(Child(Inventory2Sales.Invoiced)";

but build a dataview on the table and set the .RowFilter = "Invoiced =
false"