How to perform conditional LINQ queries?

Short answer: if (!string.IsNullOrEmpty(searchName)) { } Explanation: Build LINQ queries dynamically based on conditions. string searchName = "Alice"; var query = employees.AsQueryable(); query = query.Where(e => e.Name.Contains(searchName)); var result = query.ToList();

Example code

if (!string.IsNullOrEmpty(searchName)) { } Explanation: Build LINQ queries dynamically based on conditions. string searchName = "Alice";
var query = employees.AsQueryable();
query = query.Where(e => e.Name.Contains(searchName));
var result = query.ToList();

Real-world example (ShopNest)

ShopNest uses LINQ to query orders: filter by date, project to a summary DTO, and order by total—readable C# that becomes SQL under EF Core.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.