https://api.drupal.org/api/drupal/includes%21database%21select.inc/function/SelectQueryInterface%3A%3AleftJoin/7.x
function SelectQueryInterface::leftJoin | Drupal API
functiondrupalapi
https://adrianbailador.github.io/blog/45-leftjoin-and-rightjoin/
LeftJoin and RightJoin in EF Core 10 | Adrian Bailador | .NET
Jan 25, 2026 - EF Core 10 finally introduces native LeftJoin and RightJoin LINQ operators, replacing the verbose GroupJoin + DefaultIfEmpty pattern with clean, readable code
ef coreadrianbailador