Update DeliveryAdminWindow

Elwig/Models/WineQualLevel.cs

@@ -1,10 +1,13 @@
 using Elwig.Helpers;
 using Microsoft.EntityFrameworkCore;
+using System;
 using System.ComponentModel.DataAnnotations.Schema;
+using System.Configuration;
+using System.Security.Cryptography.Pkcs;
 
 namespace Elwig.Models {
     [Table("wine_quality_level"), PrimaryKey("QualId")]
-    public class WineQualLevel {
+    public class WineQualLevel : IEquatable<WineQualLevel> {
         [Column("qualid")]
         public string QualId { get; private set; }
 
@@ -24,5 +27,21 @@ namespace Elwig.Models {
         public string Name { get; private set; }
 
         public string MinKmwStr => (MinKmw == null) ? "" : $"(mind. {MinKmw:#.0}°)";
+
+        public override bool Equals(object? obj) {
+            return Equals(obj as WineQualLevel);
+        }
+
+        public bool Equals(WineQualLevel? obj) {
+            return QualId == obj?.QualId;
+        }
+
+        public static bool operator ==(WineQualLevel? q1, WineQualLevel? q2) {
+            return q1?.Equals(q2) ?? Equals(q1, q2);
+        }
+
+        public static bool operator !=(WineQualLevel? q1, WineQualLevel? q2) {
+            return !(q1?.Equals(q2) ?? Equals(q1, q2));
+        }
     }
 }