Fix: System.InvalidOperationException: Sequence contains no elements
This exception means you called .First() or .Single() on an empty sequence. Use FirstOrDefault/SingleOrDefault and null-check, or guard the query, or fix why the source is empty.
Tag: linq
4 posts
LINQ Gets FullJoin and Selector-Free Joins in .NET 11 Preview 5
.NET 11 Preview 5 adds a brand-new FullJoin operator to LINQ plus tuple-returning overloads for Join, LeftJoin, RightJoin, and GroupJoin that drop the result selector entirely.
IEnumerable vs IAsyncEnumerable vs IQueryable in C#: which one should the method return?
Three sequence interfaces, three execution models. Use IQueryable when a database can translate the query, IAsyncEnumerable when the producer is async and you want to stream, IEnumerable for everything else in memory.
EF Core 11 translates Contains to JSON_CONTAINS on SQL Server 2025
EF Core 11 auto-translates LINQ Contains over JSON collections to the new SQL Server 2025 JSON_CONTAINS function, and adds EF.Functions.JsonContains for path-scoped and mode-specific queries that can hit a JSON index.