FillObject: Check if keys are Dbnull, so not set

ResolveForeignKeys: Check if key is set

Database-Attribute_System/Attributes/DbForeignObject.cs

@@ -26,14 +26,15 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
             this._foreignKeyName = foreignKeyName;
         }
 
-        public void Init(FieldInfo fi, DbObject classAttribute)
+        public void Init(FieldInfo fi, DbObject classAttribute, DbObject foreignClassAttribute = null)
         {
             this.parentField = fi;
             this.classAttribute = classAttribute;
             this.foreignObjectType = fi.FieldType;
 
             // Init foreign-object class
-            DbObject foreignClassAttribute = ClassAction.Init(this.foreignObjectType);
+            if(foreignClassAttribute == null)
+                foreignClassAttribute = ClassAction.Init(this.foreignObjectType);
 
             // Check if something is weird
             if (foreignClassAttribute.primaryKeyAttributes.Count < 1) throw new InvalidOperationException($"'{foreignClassAttribute.parentClassType.Name}' does not have a primaryKey.");

Database-Attribute_System/Attributes/DbObject.cs

@@ -13,6 +13,7 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
         public string _tableName;
 
         public Type parentClassType;
+        public ConstructorInfo parentCInfo;
 
         // All childrenAttributes
         public List<BaseAttribute> baseAttributes = new List<BaseAttribute>() { };
@@ -35,6 +36,8 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
         public void Init(Type classType)
         {
             this.parentClassType = classType;
+            parentCInfo = classType.GetConstructor(Type.EmptyTypes);
+
             this._tableName = this._tableName ?? classType.Name;    // If no alternative table-name is specified, use the class-name
 
             // Iterate thru all fields
@@ -66,6 +69,9 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
                     }
                     else if (fi.GetCustomAttribute(typeof(DbForeignObject), true) is DbForeignObject fobj)    // ForeignObjects
                     {
+                        if(fi.FieldType == this.parentClassType)    // Check if we are referencing ourselfes
+                            fobj.Init(fi, this, this);
+                        else
                             fobj.Init(fi, this);
 
                         this.foreignObjectAttributes.Add(fobj);

Database-Attribute_System/ClassAction.cs

@@ -69,11 +69,17 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
                     if (baseAttribute._attributeName.ToLower() == data_keySet.Key.ToLower())
                     {
                         object value = data_keySet.Value;
+                        if (!(value is DBNull))     // Check if value is empty
+                        {
                             //if (baseAttribute.parentField.FieldType == typeof(Guid)) value = new Guid((string)value);   // If its a guid, i need to convert
 
                             baseAttribute.parentField.SetValue(classObject, value);
                             break;
                         }
+
+
+
+                    }
                 }
             }
         }
@@ -87,10 +93,13 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
         /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
         public static T GetByPrimaryKey<T>(Type classType, object primaryKeyValue, Func<string, List<Dictionary<string, object>>> queryExecutor) where T : new()
         {
-            Dictionary<string, object> primaryKeyData = new Dictionary<string, object>() { };
-            primaryKeyData.Add(null, primaryKeyValue);
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
 
-            return GetByPrimaryKey<T>(classType, primaryKeyData, queryExecutor);
+            if (dbObject.primaryKeyAttributes.Count < 1) throw new InvalidOperationException($"No primaryKey found in '{classType.Name}'");
+            if (dbObject.primaryKeyAttributes.Count > 1) throw new InvalidOperationException($"This 'GetByPrimaryKey' method only supports 1 primaryKey ('{dbObject.primaryKeyAttributes.Count}' found in '{classType.Name}')");
+
+            return GetByPrimaryKey<T>(classType, dbObject.primaryKeyAttributes[0]._attributeName, primaryKeyValue, queryExecutor);
         }
         public static T GetByPrimaryKey<T>(Type classType, string primaryKeyName, object primaryKeyValue, Func<string, List<Dictionary<string, object>>> queryExecutor) where T : new()
         {
@@ -101,12 +110,14 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
         }
         public static T GetByPrimaryKey<T>(Type classType, Dictionary<string, object> primaryKeyData, Func<string, List<Dictionary<string, object>>> queryExecutor) where T: new()
         {
-            // Create new empty object
-            T obj = new T();
-
             // Read dbObject-attribute
             DbObject dbObject = ClassAction.Init(classType);
 
+            if (dbObject.primaryKeyAttributes.Count < 1) throw new InvalidOperationException($"No primaryKey found in '{classType.Name}'");
+
+            // Create new empty object
+            T obj = (T)dbObject.parentCInfo.Invoke(null);
+
             // iterate thru them to check and fill object
             foreach (DbPrimaryKey primaryKeyAtt in dbObject.primaryKeyAttributes)
             {
@@ -130,7 +141,14 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
                 if (!dataMatchFound) throw new InvalidOperationException($"PrimaryKey='{primaryKeyAtt.parentField.Name}' is missing.");
             }
 
+            try
+            {
                 ResolveByPrimaryKey<T>(obj, queryExecutor);
+            }catch(InvalidOperationException)
+            {
+                // If there is no result, return null
+                return default(T);
+            }
             
             return obj;
         }
@@ -253,13 +271,16 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
         /// <typeparam name="T"></typeparam>
         /// <param name="classObject">Given object (marked with Db-attributes)</param>
         /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
-        public static void ResolveByPrimaryKey<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor)
+        public static void ResolveByPrimaryKey<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor, bool throwExceptions = true)
         {
             string query = QueryBuilder.SelectByPrimaryKey(classObject);   // Generate query
             List<Dictionary<string, object>> dataSet = queryExecutor(query);    // Execute
 
-            if (dataSet.Count == 0) throw new InvalidOperationException($"Cannot fetch '{typeof(T).Name}' by primary key/s. No results!");
-            FillObject(classObject, dataSet[0]);   // Fill the object
+            if (dataSet.Count == 0)
+            {
+                if (throwExceptions) throw new InvalidOperationException($"Cannot fetch '{typeof(T).Name}' by primary key/s. No results!");
+            }
+            else FillObject(classObject, dataSet[0]);   // Fill the object
         }
 
         /// <summary>
@@ -280,13 +301,14 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
             // Resolve foreignObjects
             foreach (DbForeignObject foreignObjectAtt in dbObject.foreignObjectAttributes)
             {
+                object foreignKey_value = foreignObjectAtt.foreignKeyAttribute.parentField.GetValue(classObject);
                 object foreignObject_value = foreignObjectAtt.parentField.GetValue(classObject);
 
-                // When its empty, get it & set it
-                if(foreignObject_value == null)
+                // When key is set and object is empty, get it & set it
+                if(foreignKey_value != null && foreignObject_value == null)
                 {
                     // Resolve it
-                    foreignObject_value = GetByPrimaryKey<T>(classType, foreignObjectAtt.foreignKeyAttribute.parentField.GetValue(classObject), queryExecutor);
+                    foreignObject_value = GetByPrimaryKey<T>(foreignObjectAtt.foreignObjectType, foreignKey_value, queryExecutor);
                     foreignObjectAtt.parentField.SetValue(classObject, foreignObject_value);    // Set the value
 
                     // Now scan the just resolved class to be able to set myself
@@ -442,5 +464,89 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
                 }
             }
         }
+
+
+        /// <summary>
+        /// Updates class to database-object</pragma>
+        /// Only works with primary-key/s!
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
+        /// <param name="max_depth">Determents how deep resolving will be executed (if the corresponding foreignKey-object is resolved)</param>
+        public static void Update<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor, int max_depth = 1)
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classObject.GetType());
+
+            if(max_depth-1 > 0)
+            {
+                // Update all foreignObjects before handling myself
+                foreach (DbForeignObject foreignObject in dbObject.foreignObjectAttributes)
+                {
+                    object foreignObjectRef = foreignObject.parentField.GetValue(classObject);
+                    if (foreignObjectRef != null)
+                        Update(foreignObjectRef, queryExecutor, max_depth - 1);
+                }
+            }
+
+            string updateQuery = QueryBuilder.UpdateByPrimaryKey(classObject);
+            queryExecutor.Invoke(updateQuery);
+        }
+
+        /// <summary>
+        /// Inserts class to database-object
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
+        /// <param name="max_depth">Determents how deep insertion will be executed (if the corresponding foreignKey-object is resolved)</param>
+        public static void Insert<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor, int max_depth = 1)
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classObject.GetType());
+
+            if (max_depth - 1 > 0)
+            {
+                // Update all foreignObjects before handling myself
+                foreach (DbForeignObject foreignObject in dbObject.foreignObjectAttributes)
+                {
+                    object foreignObjectRef = foreignObject.parentField.GetValue(classObject);
+                    if (foreignObjectRef != null)
+                        Insert(foreignObjectRef, queryExecutor, max_depth - 1);
+                }
+            }
+
+            string insertQuery = QueryBuilder.InsertAttributesByObject(classObject);
+            queryExecutor.Invoke(insertQuery);
+        }
+
+        /// <summary>
+        /// Deletes class from database-object</pragma>
+        /// Only works with primary-key/s!
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
+        /// <param name="max_depth">Determents how deep deletion will be executed (if the corresponding foreignKey-object is resolved)</param>
+        public static void Delete<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor, int max_depth = 1)
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classObject.GetType());
+
+            if (max_depth - 1 > 0)
+            {
+                // Update all foreignObjects before handling myself
+                foreach (DbForeignObject foreignObject in dbObject.foreignObjectAttributes)
+                {
+                    object foreignObjectRef = foreignObject.parentField.GetValue(classObject);
+                    if (foreignObjectRef != null)
+                        Delete(foreignObjectRef, queryExecutor, max_depth - 1);
+                }
+            }
+
+            string deleteQuery = QueryBuilder.DeleteByPrimaryKey(classObject);
+            queryExecutor.Invoke(deleteQuery);
+        }
     }
 }

Database-Attribute_System/Database-Attribute_System.csproj

@@ -4,7 +4,7 @@
     <TargetFramework>netcoreapp2.1</TargetFramework>
     <RootNamespace>eu.railduction.netcore.dll.Database_Attribute_System</RootNamespace>
     <SignAssembly>false</SignAssembly>
-    <Version>1.5.20</Version>
+    <Version>1.5.21</Version>
   </PropertyGroup>
 
 </Project>