What does Include and ThenInclude do?
PICTURE THIS: HOW TO EXPLAIN IT
IdeaEF Core
HowWhat happens inside
Why they askShows real use
Simple meaning
They eager-load related data in one query.
WHY — EF Core instead of guessing?
Why interviewers care about EF Core:
EF Core questions separate
people who only read docs from people who shipped.
Keep it short, concrete,
and tied to .NET work.
Stay structured
Name the idea, why it exists, then one short example.
Close cleanly
End with when you use it and one common pitfall.
STEPS — What happens step by step?
Before you speak the answer, walk the interviewer through these steps:
- 1They eager-load related data
in one query.
- 2Why it exists
Over-including creates cartesian explosions.
- 3I project to DTOs
when I only need a few columns.
- 4Give an example
One tiny concrete case you can say aloud.
- 5Common mistake
What juniors usually get wrong.
- 6Close
When you pick this over the alternative.
EXAMPLE — See it in action
Here's a short line you can speak, broken into clear beats:
Say this line
“Over-including creates cartesian explosions.”
Break into beats
Overincludingcreatescartesianexplosions
Speaking order
298740833747163290
Note: Adapt this scaffold to your own project — keep it under 60–90 seconds.
Key takeaway
They eager-load related data in one query. Over-including creates cartesian explosions.