Create query filter for soft delete on League and add an example function.

EntityFrameworkCore.Console/Program.cs

@@ -22,6 +22,23 @@ context.Database.EnsureCreated();
 // Rather than raise: "System.InvalidOperationException: Sequence contains no elements."
 // var firstCoach = await context.Coaches.FirstOrDefaultAsync();
 
+async Task SoftDeleteLeague()
+{
+  var league = context.Leagues.Find(1);
+  league.IsDeleted = true;
+
+  context.SaveChanges();
+
+  // This is rather cumbersome. Instead, use a query filter. See League configuration.
+  //var leagues = context.Leagues.Where(l => !l.IsDeleted).ToList();
+
+  // This now gets all leagues, with query filters applied.
+  var leagues = context.Leagues.ToList();
+
+  // You can also ignore them, if you want in a specific case.
+  leagues = context.Leagues.IgnoreQueryFilters().ToList();
+}
+
 async Task ConcurrencyCheckExample()
 {
   var team = context.Teams.Find(1);

EntityFrameworkCore.Data/Configurations/LeagueConfiguration.cs

@@ -8,6 +8,10 @@ public class LeagueConfiguration : IEntityTypeConfiguration<League>
 {
   public void Configure(EntityTypeBuilder<League> builder)
   {
+    // This query filter will be always applied.
+    // Note that you should call HasQueryFilter only once, otherwise the filter is overwritten.
+    builder.HasQueryFilter(l => l.IsDeleted == false);
+
     builder.HasData(
       new League { Id = 1, Name = "Local League", CreatedDate = new DateTime(2025, 4, 6, 17, 7, 27, 33)},
       new League { Id = 2, Name = "National League", CreatedDate = new DateTime(2025, 4, 6, 17, 7, 27, 33)},