Question

Does anyone know how I can select a row and column dynamically in EF4? (VB)

A bit like a map, I want to navigate through the data using x and y axis to pull out one fields value,

SQL would look like this

SELECT ” & MyColumbVariable & ” FROM MyTable WHERE MyRow = ” & MyVariable & “

Bit of a hack I know its not great. Perhaps there is a cleaner way to do this?

Thanks

Answer 1

You can use CreateQuery method of object context. Assuming you are using 4.1+:

var result = ((IObjectContextAdapter)context)
            .ObjectContext.CreateQuery<Entity>(query);

If you’re using 4.0 there’s no need to cast to IObjectContextAdapter since your context is alreay of type ObjectContext.
Update:

You can also build expression trees yourself to build dynamic queries. It’s a bit of work but you can use it everywhere by writing it in a generic way. A good sample has been explained here. Also search for Dynamic Queries/Building expression trees in Entity Framework and you’ll find some good tutorials.