Fixes to model:

- added relationship contact-quote (0,1:n).
- changed relationship CD - product to 0,1:n.
- removed FK 'ProductId' from CD (no longer required due to relationsship change).
- removed property 'LinkToSap' from contact model.
- fixed LineItem PK (was 'QuoteId').
- fixed LineItem - quote relationsship.
- specified FK in some relationships to avoid duplicate fields generated by wrong EF Core guesses.
- set all PKs to Uint.
- Moved FKs in Quote.cs up.
- RegisteredUser.cs and RUSettings.cs: moved metadata down.

Gremlin/GremlinData/DBClasses/DbHelper.cs

@@ -79,8 +79,6 @@ namespace Gremlin.GremlinData.DBClasses
         /// Initialzes the Db with enum data: product lines, account types, submarkets
 
         {
-            DateTime now = DateTime.Now;
-
             //PRODUCT LINES
             string[] ProductLineAbbrviations = { "XF", "LM", "XA", "RB", "GE",
                                                  "9Z", "9P", "9M", "9K", "9H",
@@ -1051,6 +1049,8 @@ namespace Gremlin.GremlinData.DBClasses
                 {
                     // Read current line fields, pointer moves to the next line.
                     string[] fields = csvParser.ReadFields();
+                    //string productNumber = fields[0];
+                    //string? optionNumber = fields[1] == "" ? null : fields[1];
                     CustomDescription ImportedCD = new()
                     {
                         ProductNumber = fields[0],

Gremlin/GremlinData/DBClasses/EntityConfiguration.cs

@@ -64,7 +64,6 @@ namespace Gremlin.GremlinData.DBClasses
             entity.Property(e => e.OptInStatus).HasDefaultValue(null);
             entity.Property(e => e.IsReference).HasDefaultValue(false);
             entity.Property(e => e.Notes);
-            entity.Property(e => e.LinkToSAP);
             entity.Property(e => e.ValidatedContact).HasDefaultValue(false);
             
             entity.Property(e => e.DataCreationDate).HasColumnType("TIMESTAMP").HasDefaultValueSql("CURRENT_TIMESTAMP").ValueGeneratedOnAdd();
@@ -121,8 +120,8 @@ namespace Gremlin.GremlinData.DBClasses
     {
         public void Configure(EntityTypeBuilder<LineItem> entity)
         {
-            entity.HasKey(e => e.QuoteId);
-            entity.HasOne(p => p.Quote).WithMany(d => d.LineItems).HasForeignKey(fk => fk.QuoteId);
+            entity.HasKey(e => e.LineItemId);
+            entity.HasOne(p => p.Quote).WithMany(d => d.LineItems).HasForeignKey(fk => fk.QuoteId).IsRequired(true).OnDelete(DeleteBehavior.Cascade);
             
             entity.Property(e => e.Position).IsRequired(true);
             entity.Property(e => e.Amount).IsRequired(true);
@@ -159,8 +158,8 @@ namespace Gremlin.GremlinData.DBClasses
         public void Configure(EntityTypeBuilder<Product> entity)
         {
             entity.HasKey(e => e.ProductId);
-            entity.HasOne(d => d.CustomDescription).WithMany(p => p.Products).IsRequired(false).OnDelete(DeleteBehavior.Restrict);
-            entity.HasOne(p => p.ProductLine).WithMany(d => d.Products).IsRequired(true).OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(d => d.CustomDescription).WithMany(p => p.Products).HasForeignKey("CustomDescriptionId").IsRequired(false).OnDelete(DeleteBehavior.Restrict);
+            entity.HasOne(p => p.ProductLine).WithMany(d => d.Products).HasForeignKey("ProductLineCode").IsRequired(true).OnDelete(DeleteBehavior.Restrict);
             
             entity.Property(e => e.ProductNumber).IsRequired(true);
             entity.Property(e => e.OptionNumber);

Gremlin/GremlinData/DBClasses/GenericImporter.cs

@@ -321,7 +321,7 @@ namespace Gremlin.GremlinData.DBClasses
                         DataValidUntil = FarInTheFuture,
                         DataVersionComment = "Initial Importer by CD-ImporterFomCsv",
                     };
-                    ImportedCD.Products = new();
+                    ImportedCD.Products = new List<Product>();
                     ImportedCD.Supplier = new();
                     ImportedCD.Supplier.AccountName = fields[2] is "" or "RB" ? "Agilent Technologies" : fields[2];
                     ImportedCD.DataCreationDate = ImportedCD.DataValidFrom = ImportedCD.DataModificationDate = DateTime.Now;

Gremlin/GremlinData/EntityClasses/Account.cs

@@ -11,7 +11,7 @@ namespace Gremlin.GremlinData.EntityClasses
 
         //foreign keys:
         public IList<Contact> Contacts { get; set; }
-        public int? ParentAccountId { get; set; }
+        public uint? ParentAccountId { get; set; }
         public AccountType AccountType { get; set; }
         public SubMarket SubMarket { get; set; }
         public IList<CustomDescription> CustomDescriptions { get; set; }

Gremlin/GremlinData/EntityClasses/Contact.cs

@@ -44,8 +44,7 @@ namespace Gremlin.GremlinData.EntityClasses
         public string SAPApplicationInterest { get; set; }
         public string SAPJobLevel { get; set; }
         public string SAPCompetitiveIBase { get; set; }
-        public string LinkToSAP { get; set; }
-
+        
         //metadata:
         public DateTime DataCreationDate { get; set; }
         public DateTime DataModificationDate { get; set; }

Gremlin/GremlinData/EntityClasses/CustomDescription.cs

@@ -9,7 +9,7 @@ namespace Gremlin.GremlinData.EntityClasses
         public uint CustomDescriptionId { get; set; }
        
         //foreign keys:
-        public uint ProductId { get; set; }
+        //public uint ProductId { get; set; }
         public uint AccountId { get; set; }
 
         //navigation properties:

Gremlin/GremlinData/EntityClasses/Product.cs

@@ -12,7 +12,7 @@ namespace Gremlin.GremlinData.EntityClasses
         public ProductLine ProductLine { get; set; }
 
         //foreign keys
-        public int CustomDescriptionId { get; set; }
+        public uint CustomDescriptionId { get; set; }
         public string ProductLineCode { get; set; }
         
         //Agilent-specific properties:

Gremlin/GremlinData/EntityClasses/Quote.cs

@@ -9,18 +9,18 @@ namespace Gremlin.GremlinData.EntityClasses
         public uint QuoteId { get; set; }
 
         //foreign keys:
+        public Contact Recipient { get; set; }
         public IList<LineItem> LineItems { get; set; }
 
         //navigation properties:
         //NONE
 
         //class properties:
+        public Contact SalesRep { get; set; }
         public string QuotationNumber { get; set; }
         public DateTime QuotationDate { get; set; }
         public DateTime ValidUntil { get; set; }
         public byte ValidFor { get; set; }
-        public Contact Recipient { get; set; }
-        public Contact SalesRep { get; set; }
         public decimal TotalListprice { get; set; }
         public decimal TotalDiscount { get; set; }
         public decimal TotalNet { get; set; }

Gremlin/GremlinData/EntityClasses/RUSetting.cs

@@ -13,15 +13,15 @@ namespace Gremlin.GremlinData.EntityClasses
         //navigation properties
         public RegisteredUser RegisteredUser { get; set; }
 
-        //standard properties:
-        public DateTime DataCreationDate { get; set; }
-        public DateTime DataModificationDate { get; set; }
-        public string DataModificationByUser { get; set; }
-
         //class properties
         public string SettingKey { get; set; }
         public string SettingValue { get; set; }
 
+        //metadata (subset of IMetadata)
+        public DateTime DataCreationDate { get; set; }
+        public DateTime DataModificationDate { get; set; }
+        public string DataModificationByUser { get; set; }
+
         //Constructur
         public RUSetting()
         {

Gremlin/GremlinData/EntityClasses/RegisteredUser.cs

@@ -11,14 +11,14 @@ namespace Gremlin.GremlinData.EntityClasses
         //navigation properties
         public IList<RUSetting> RUSettings { get; set; }
 
-        //standard properties
-        public DateTime DataCreationDate { get; set; }
-        public DateTime DataModificationDate { get; set; }
-        public string DataModificationByUser { get; set; }
-
         //class properties
         public string UserName { get; set; }
         public string PasswordHash { get; set; }
+        
+        //metadata (subset of IMetadata)
+        public DateTime DataCreationDate { get; set; }
+        public DateTime DataModificationDate { get; set; }
+        public string DataModificationByUser { get; set; }
 
         //Constructur
         public RegisteredUser()