How to select an Entity class name from combobox and use it as a variable in a linq to Entities Query ?

Samio

Hi,

In My project I have an Entity Model,

In Form1, I have Combobox1 populated with Entities Names (EntityName1, EntityName2, EntityName3)

I wonder how to use the selected value of the combobox as a variable in a linq to Entities Query ?

something like:

var query = (from p in Context.(Combobox.selectedValue) select new { p.ID, p.field1 }).ToList();

Thanks

2 Replies

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Samio14y ago
Thanks Vulpes,

That's a good alternative, spite of I'll suffer with about 20 separate cases,

but I'll begin the job and try it anyway pending the idea matures yet.
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Vulpes14y ago
You can only use a string in that fashion if you're using reflection which I don't think is a practical proposition with something as complex as the entity framework.

Remember also that the type parameter, T, of the resulting List will be different for each entity

If there are only a few entities, I'd just use a switch statement and deal with each one individually:

switch(combobox.SelectedItem.ToString())
{
case "EntityName1" :

var query1 = (from p in Context.EntityName1 select new { p.ID, p.field1 }).ToList();
// do something with query1
break;

case "EntityName2" :

var query2 = (from p in Context.EntityName2 select new { p.ID, p.field1 }).ToList();
// do something with query2
break;

// and so on
}
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