Question

The problem is: I have a list of objects, with some containing the same PlanId property value. I want to only grab the first occurrence of those and ignore the next object with that PlanId. The root problem is a View in the database, but it’s tied in everywhere and I don’t know if changing it will break a ton of stuff nearing a deadline, so I’m tossing in a hack for now.

So, if I have a list of PlanObjects like such.

• Plan1.PlanId = 1
• Plan2.PlanId = 1
• Plan3.PlanId = 2
• Plan4.PlanId = 3
• Plan5.PlanId = 4
• Plan6.PlanId = 4

I want to take a sub-list from that with LINQ (italics mean an item is not included)

• Plan1.PlanId = 1
• Plan2.PlanId = 1
• Plan3.PlanId = 2
• Plan4.PlanId = 3
• Plan5.PlanId = 4
• Plan6.PlanId = 4

For my needs, it doesn’t matter which one is taken first. The Id is used to update a datbase record.

If I didn’t explain that well enough, let me know and I’ll edit the question. I think it makes sense though.

Answer 1

PlanObjects.GroupBy(p => p.PlanId).Select(r => r.First());