Add note about JOINs in SQL queries.

EntityFrameworkCore.Console/Program.cs

@@ -65,6 +65,9 @@ async Task RawSQLStatement()
     Console.WriteLine($"SQL Raw Team: {t.Name}");
   }
 
+  // Note, that you cannot use JOINs in these SQL queries.
+  // Instead, the Include() function is used to add related data.
+
   // FromSqlInterpolated is the revised form of FromSql, and a better choice.
   teams = context.Teams.FromSqlInterpolated($"SELECT * FROM Teams WHERE name = {teamName}");
   foreach (var t in teams)