Billing: Add possibility to automatically add business shares

Elwig/Models/Entities/MemberHistory.cs

@@ -0,0 +1,31 @@
+using Microsoft.EntityFrameworkCore;
+using System;
+using System.ComponentModel.DataAnnotations.Schema;
+
+namespace Elwig.Models.Entities {
+    [Table("member_history"), PrimaryKey("MgNr", "DateString")]
+    public class MemberHistory {
+        [Column("mgnr")]
+        public int MgNr { get; set; }
+
+        [Column("date")]
+        public string DateString { get; set; }
+        [NotMapped]
+        public DateOnly Date {
+            get => DateOnly.ParseExact(DateString, "yyyy-MM-dd");
+            set => value.ToString("yyyy-MM-dd");
+        }
+
+        [Column("business_shares")]
+        public int BusinessShares { get; set; }
+
+        [Column("type")]
+        public string Type { get; set; }
+
+        [Column("comment")]
+        public string? Comment { get; set; }
+
+        [ForeignKey("MgNr")]
+        public virtual Member Member { get; private set; }
+    }
+}