S9022 — Redundant "Include" calls should be removed

An Include or ThenInclude call can be entirely inert: Entity Framework Core generates the exact same SQL with or without it.

Why is this an issue?

Entity Framework Core resolves the navigation path of every Include/ThenInclude call and merges calls that resolve to the same path into a single join. Repeating Include for a navigation that is already included, without adding a new ThenInclude afterwards, generates identical SQL to removing the repeated call — it adds nothing but noise and can mislead a reader into thinking it changes what is loaded.

Exceptions

The rule does not apply when:

• the repeated Include call re-anchors the chain before a different ThenInclude. Entity Framework Core has no syntax for attaching two different ThenInclude continuations to one Include, so repeating it is the idiomatic way to load two independent nested navigations or collections.
• one of the calls applies a filter (through Where, Skip, Take, or similar) that the other does not carry, regardless of which one is written first — removing the filtered call would change which rows are loaded.

How to fix it

Remove the Include (or ThenInclude) call that has no effect.

Code examples

Noncompliant code example

var students = await context.Students
    .Include(s => s.Enrollments) // Noncompliant: "Enrollments" is already included below
    .Include(s => s.Enrollments)
    .ToListAsync();

Compliant solution

var students = await context.Students
    .Include(s => s.Enrollments)
    .ToListAsync();

This repeated Include is not redundant — it branches into two different ThenInclude calls:

var students = await context.Students
    .Include(s => s.Enrollments).ThenInclude(e => e.Course)
    .Include(s => s.Enrollments).ThenInclude(e => e.Student) // Compliant: re-anchors before a different ThenInclude
    .ToListAsync();

Resources

Documentation

• Microsoft Learn - Loading related data - Eager loading

Related rules

• {rule:csharpsquid:S8733} - covers loading multiple sibling collections in a single query; this rule instead covers Include calls that add nothing to the query at all.
• {rule:csharpsquid:S9023} - covers Include calls that silently drop real data, not just harmless no-ops.