Aggregate sum of string typed values

[hermann]

Hi,
I'd just like to know, what would be the best way to aggregate a columns sum, where the column type is string. So the items would be "10", "20", "30".

Many thanks,
Hermann

[hermann]

Oh my,
all I needed to do is to overrule the column type in the datasources' model

{field: "MyStringField", type : "number" }

Sorry for bothering...