Ser version

Added Init() to initialise necessary classes
Changed structure and added a BaseAttribute
Fixed occuring errors to match new system

Database-Attribute_System/Attributes/BaseAttribute.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
+{
+    public class BaseAttribute : Attribute
+    {
+        public FieldInfo parentField;
+        public DbObject classAttribute;
+
+        public string _attributeName;
+
+        public BaseAttribute()
+        {
+
+        }
+    }
+}

Database-Attribute_System/Attributes/BaseAttributes/DbAttribute.cs

@@ -1,15 +1,14 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 
 namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
 {
     [AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
-    public class DbAttribute : Attribute
+    public class DbAttribute : BaseAttribute
     {
-        public string _attributeName;
-
         /// <summary>
         /// Marks variable as database-attribute
         /// </summary>
@@ -18,5 +17,13 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
         {
             this._attributeName = attributeName;
         }
+
+        public void Init(FieldInfo fi, DbObject classAttribute)
+        {
+            this.parentField = fi;
+            this.classAttribute = classAttribute;
+
+            this._attributeName = this._attributeName ?? fi.Name;     // If no alternative attribute-name is specified, use the property-name
+        }
     }
 }

Database-Attribute_System/Attributes/BaseAttributes/DbForeignKey.cs

@@ -1,25 +1,29 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 
 namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
 {
     [AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
-    public class DbForeignKey : Attribute
+    public class DbForeignKey : BaseAttribute
     {
-        public Type _classType;
-        public string _attributeName;
-
         /// <summary>
         /// Marks variable as foreignKey of given class
         /// </summary>
-        /// <param name="classType">Type of class to which this is the ForeignKey</param>
         /// <param name="dbAttributeName">Name of database-attribute (case-sensitivity is determined from database-attribute-settings) ['null' if the same as field-name]</param>
-        public DbForeignKey(Type classType, string attributeName = null)
+        public DbForeignKey(string attributeName = null)
         {
-            this._classType = classType;
             this._attributeName = attributeName;
         }
+
+        public void Init(FieldInfo fi, DbObject classAttribute)
+        {
+            this.parentField = fi;
+            this.classAttribute = classAttribute;
+
+            this._attributeName = this._attributeName ?? fi.Name;     // If no alternative attribute-name is specified, use the property-name
+        }
     }
 }

Database-Attribute_System/Attributes/BaseAttributes/DbPrimaryKey.cs

@@ -1,23 +1,29 @@
 using System;
 using System.Collections.Generic;
 using System.Linq;
+using System.Reflection;
 using System.Threading.Tasks;
 
 namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
 {
     [AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
-    public class DbPrimaryKey : Attribute
+    public class DbPrimaryKey : BaseAttribute
     {
-        public Type _classType;
-        public string _attributeName;
-
         /// <summary>
         /// Marks variable as primaryKey fo current class
         /// </summary>
         /// <param name="dbAttributeName">Name of database-attribute (case-sensitivity is determined from database-attribute-settings) ['null' if the same as field-name]</param>
         public DbPrimaryKey(string attributeName = null)
         {
-            this._attributeName = attributeName;
+            this._attributeName = attributeName;    // Todo: Automatic resolving of name if it is null (?)
+        }
+
+        public void Init(FieldInfo fi, DbObject classAttribute)
+        {
+            this.parentField = fi;
+            this.classAttribute = classAttribute;
+
+            this._attributeName = this._attributeName ?? fi.Name;     // If no alternative attribute-name is specified, use the property-name
         }
     }
 }

Database-Attribute_System/Attributes/DbForeignObject.cs

@@ -0,0 +1,79 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Reflection;
+using System.Threading.Tasks;
+
+namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
+{
+    [AttributeUsage(AttributeTargets.Field, Inherited = false, AllowMultiple = false)]
+    public class DbForeignObject : Attribute
+    {
+        public Type foreignObjectType;
+
+        public string _foreignKeyName;
+        public DbForeignKey foreignKeyAttribute;
+
+        public FieldInfo parentField;
+        public DbObject classAttribute;
+
+        /// <summary>
+        /// Marks variable as foreign-object of an dbObject
+        /// </summary>
+        /// <param name="foreignKeyName">Fieldname of foreignKey associated with the foreignObject</param>
+        public DbForeignObject(string foreignKeyName = null)
+        {
+            this._foreignKeyName = foreignKeyName;
+        }
+
+        public void Init(FieldInfo fi, DbObject classAttribute)
+        {
+            this.parentField = fi;
+            this.classAttribute = classAttribute;
+            this.foreignObjectType = fi.GetType();
+
+            // Init foreign-object class
+            DbObject foreignClassAttribute = ClassAction.Init(this.foreignObjectType);
+
+            // Check if something is weird
+            if (foreignClassAttribute.primaryKeyAttributes.Count < 1) throw new InvalidOperationException($"'{foreignClassAttribute.parentClassType.Name}' does not have a primaryKey.");
+            if (foreignClassAttribute.primaryKeyAttributes.Count > 1) throw new InvalidOperationException($"ForeignObject does not support multiple primaryKeys.");
+
+            Type primaryKeyType = foreignClassAttribute.primaryKeyAttributes[0].parentField.GetType();  // Read type of primaryKey in foreignObject-class
+            foreach(DbForeignKey foreignKey in classAttribute.foreignKeyAttributes)     // Search for matching foreignKey
+            {
+                if(this._foreignKeyName != null)     // If i have a name
+                {
+                    // check if name matches
+                    if (foreignKey.parentField.Name.ToLower() == this._foreignKeyName)
+                    {
+                        if(foreignKey.parentField.GetType() == primaryKeyType)
+                        {
+                            this._foreignKeyName = foreignKey.parentField.Name;
+                            foreignKeyAttribute = foreignKey;
+                            break;
+                        }
+                        else
+                        {
+                            // If a name was specified and the key does not match its an error
+                            throw new InvalidOperationException($"ForeignKey='{this._foreignKeyName}' is typeOf='{foreignKey.parentField.GetType().Name}' but primaryKey of foreignObject-class is typeOf='{primaryKeyType.Name}'.");
+                        }
+                    }
+                }
+                else    // No name
+                {
+                    // Check if type matches
+                    if (foreignKey.parentField.GetType() == primaryKeyType)
+                    {
+                        this._foreignKeyName = foreignKey.parentField.Name;
+                        foreignKeyAttribute = foreignKey;
+                        break;
+                    }
+                }
+            }
+
+            // Check if key-retrieval was successful
+            if (foreignKeyAttribute == null) throw new InvalidOperationException($"No coresponding foreignKey.");
+        }
+    }
+}

Database-Attribute_System/Attributes/DbObject.cs

@@ -12,13 +12,68 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System.Attributes
     {
         public string _tableName;
 
+        public Type parentClassType;
+
+        // All childrenAttributes
+        public List<BaseAttribute> baseAttributes = new List<BaseAttribute>() { };
+        public List<DbPrimaryKey> primaryKeyAttributes = new List<DbPrimaryKey>() { };
+        public List<DbAttribute> attributeAttributes = new List<DbAttribute>() { };
+        public List<DbForeignKey> foreignKeyAttributes = new List<DbForeignKey>() { };
+        public List<DbForeignObject> foreignObjectAttributes = new List<DbForeignObject>() { };
+
         /// <summary>
         /// Marks variable as database-table
         /// </summary>
         /// <param name="tableName">Name of database-table (case-sensitivity is determined from database-table-settings) ['null' if the same as class-name]</param>
         public DbObject(string tableName = null)
         {
-            this._tableName = tableName;
+            this._tableName = tableName;    // Todo: Automatic resolving of name if it is null (?)
+        }
+
+        public void Init(Type classType)
+        {
+            this.parentClassType = classType;
+            this._tableName = this._tableName ?? classType.Name;    // If no alternative table-name is specified, use the class-name
+
+            // Iterate thru all fields
+            foreach (System.Reflection.FieldInfo fi in classType.GetRuntimeFields())
+            {
+                try
+                {
+                    // Check if current field is a db-field and initiate it
+                    if (fi.GetCustomAttribute(typeof(DbPrimaryKey), true) is DbPrimaryKey pkey)     // PrimaryKey
+                    {
+                        pkey.Init(fi, this);
+
+                        this.baseAttributes.Add(pkey);
+                        this.primaryKeyAttributes.Add(pkey);
+                    }
+                    else if (fi.GetCustomAttribute(typeof(DbAttribute), true) is DbAttribute att)   // Attributes
+                    {
+                        att.Init(fi, this);
+
+                        this.baseAttributes.Add(att);
+                        this.attributeAttributes.Add(att);
+                    }
+                    else if (fi.GetCustomAttribute(typeof(DbForeignKey), true) is DbForeignKey fkey)    // ForeignKeys
+                    {
+                        fkey.Init(fi, this);
+
+                        this.baseAttributes.Add(fkey);
+                        this.foreignKeyAttributes.Add(fkey);
+                    }
+                    else if (fi.GetCustomAttribute(typeof(DbForeignObject), true) is DbForeignObject fobj)    // ForeignObjects
+                    {
+                        fobj.Init(fi, this);
+
+                        this.foreignObjectAttributes.Add(fobj);
+                    }
+                }
+                catch(InvalidOperationException ex)
+                {
+                    throw new InvalidOperationException($"Cannot init foreignObject-field '{fi.Name}' of '{classType.Name}'. {ex.Message}", ex);
+                }
+            }
         }
     }
 }

Database-Attribute_System/ClassAction.cs

@@ -0,0 +1,202 @@
+using eu.railduction.netcore.dll.Database_Attribute_System.Attributes;
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace eu.railduction.netcore.dll.Database_Attribute_System
+{
+    public class ClassAction
+    {
+        private static List<Type> initiatedClassTypes = new List<Type>() { };
+        /// <summary>
+        /// Initiates the attribute-system and preloads all necessary information<para/>
+        /// INFO: Will initiate necessary foreignObjects recursively!<para/>
+        /// If an class is already initiated, it will be ignored!
+        /// </summary>
+        /// <param name="classType">The classType to preload</param>
+        /// <returns>DbObject-attribute corresponding to the class</returns>
+        public static DbObject Init(Type classType)
+        {
+            // Check if given class is marked as dbObject
+            if (!(classType.GetCustomAttribute(typeof(DbObject), true) is DbObject dbObject)) throw new InvalidOperationException($"Cannot init '{classType.Name}'. Missing Attribute 'DbObject'");
+
+            if (!initiatedClassTypes.Contains(classType))
+            {
+                dbObject.Init(classType);   // Init dbObject
+                initiatedClassTypes.Add(classType);     // Set it to the list
+            }
+
+            return dbObject;
+        }
+
+
+        /// <summary>
+        /// Fills an given dbObject with given data<para/>
+        /// Data-attribute-names and class-fieldNames have to match! (non case-sensitive)
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <param name="data">The data</param>
+        /// <param name="runDataLossChecks">This checks if any class-field and data-attribute does not exists in either (Slower)</param>
+        public static void FillObject<T>(T classObject, Dictionary<string, object> data)
+        {
+            Type classType = classObject.GetType();
+
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            // Iterate through data
+            foreach (KeyValuePair<string, object> data_keySet in data)
+            {
+                // Interate through class-fields
+                foreach (BaseAttribute baseAttribute in dbObject.baseAttributes)
+                { 
+                    // If its a match, set the value
+                    if (baseAttribute._attributeName.ToLower() == data_keySet.Key.ToLower())
+                    {
+                        baseAttribute.parentField.SetValue(classObject, data_keySet.Value);
+                        break;
+                    }
+                }
+            }
+        }
+
+
+        /// <summary>
+        /// Gets an dbObject by primaryKey/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>
+        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);
+
+            return GetByPrimaryKey<T>(classType, primaryKeyData, queryExecutor);
+        }
+        public static T GetByPrimaryKey<T>(Type classType, string primaryKeyName, object primaryKeyValue, Func<string, List<Dictionary<string, object>>> queryExecutor) where T : new()
+        {
+            Dictionary<string, object> primaryKeyData = new Dictionary<string, object>() { };
+            primaryKeyData.Add(primaryKeyName, primaryKeyValue);
+
+            return GetByPrimaryKey<T>(classType, primaryKeyData, queryExecutor);
+        }
+        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);
+
+            // iterate thru them to check and fill object
+            foreach (DbPrimaryKey primaryKeyAtt in dbObject.primaryKeyAttributes)
+            {
+                bool dataMatchFound = false;
+
+                // Now search the corresponding primaryKeyData
+                foreach (KeyValuePair<string, object> primaryKey in primaryKeyData)
+                {
+                    // primaryKey matches
+                    if(primaryKeyAtt._attributeName.ToLower() == primaryKey.Key.ToLower())
+                    {
+                        // Set data
+                        primaryKeyAtt.parentField.SetValue(obj, primaryKey.Value);
+
+                        dataMatchFound = true;
+                        break;
+                    }
+                }
+
+                // If no data was found matching this field
+                if (!dataMatchFound) throw new InvalidOperationException($"Cannot create object with primaryKeyData. No data assigned to field '{primaryKeyAtt.parentField.Name}'");
+            }
+
+            ResolveByPrimaryKey<T>(obj, queryExecutor);
+
+            return obj;
+        }
+
+        /// <summary>
+        /// Resolves dbObject by primaryKey/s<pragma/>
+        /// Object needs to have primaryKey/s set!
+        /// </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>
+        public static void ResolveByPrimaryKey<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor)
+        {
+            string query = QueryBuilder.SelectByPrimaryKey(classObject);   // Generate query
+            List<Dictionary<string, object>> dataSet = queryExecutor(query);    // Execute
+            FillObject(classObject, dataSet[0]);   // Fill the object
+        }
+        
+        /// <summary>
+        /// Gets a list of dbObjects by attribute/s
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classType">Type of class</param>
+        /// <param name="fields">class-fields for select</param>
+        /// <param name="queryExecutor">Function to handle query-calls - Has to return Dictionary[attributeName, attributeValue]</param>
+        /// <param name="runDataLossChecks">This checks if any class-field and data-attribute does not exists in either (Slower)</param>
+        /// <returns>List of dbObjects</returns>
+        public static List<T> GetListByAttribute<T>(Type classType, Dictionary<string, object> fields, Func<string, List<Dictionary<string, object>>> queryExecutor) where T : new()
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            Function.ConvertAttributeToDbAttributes(classType, fields);
+
+            string query = QueryBuilder.SelectByAttribute(dbObject._tableName, fields);   // Generate query
+            List<Dictionary<string, object>> dataSet = queryExecutor(query);    // Execute
+
+            List<T> objs = new List<T>() { };
+            foreach(Dictionary<string, object> data in dataSet)
+            {
+                T obj = new T();    // New object
+                FillObject(obj, data);   // Fill it
+                objs.Add(obj);      // Add to list
+            }
+
+            return objs;    // Return list
+        }
+
+
+
+        /// <summary>
+        /// Resolves all foreignKeys with the database<pragma/>
+        /// Only works if the foreignKey is single (not assembled)!
+        /// </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</param>
+        /// <param name="runDataLossChecks">This checks if any class-field and data-attribute does not exists in either (Slower)</param>
+        public static void ResolveForeignKeys<T>(T classObject, Func<string, List<Dictionary<string, object>>> queryExecutor, int max_depth = 1) where T: new()
+        {
+            Type classType = classObject.GetType();
+
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            foreach (DbForeignObject foreignObjectAtt in dbObject.foreignObjectAttributes)
+            {
+                object foreignObject_value = foreignObjectAtt.parentField.GetValue(classObject);
+
+                // When its empty, get it
+                if(foreignObject_value == null)
+                {
+                    foreignObject_value = GetByPrimaryKey<T>(classType, foreignObjectAtt.foreignKeyAttribute.parentField.GetValue(classObject), queryExecutor); ;
+                }
+
+                // Recursive resolving
+                if (max_depth - 1 > 0)
+                {
+                    ResolveForeignKeys(foreignObject_value, queryExecutor, max_depth - 1);
+                }
+            }
+        }
+    }
+}

Database-Attribute_System/Database-Attribute_System.csproj

@@ -4,6 +4,7 @@
     <TargetFramework>netcoreapp2.1</TargetFramework>
     <RootNamespace>eu.railduction.netcore.dll.Database_Attribute_System</RootNamespace>
     <SignAssembly>false</SignAssembly>
+    <Version>1.5.5</Version>
   </PropertyGroup>
 
 </Project>

Database-Attribute_System/Function.cs

@@ -1,20 +0,0 @@
-using System;
-using System.Collections.Generic;
-using System.Text;
-
-namespace eu.railduction.netcore.dll.Database_Attribute_System
-{
-    class Function
-    {
-        public static string SqlEscape(string str)
-        {
-            string str_cpy = str.Replace(@"'", @"\'");
-            return str_cpy;
-        }
-
-        public static string SqlSerialise(DateTime dt)
-        {
-            return dt.ToString("yyyy-MM-dd HH:mm:ss");
-        }
-    }
-}

Database-Attribute_System/QueryBuilder.cs

@@ -8,80 +8,154 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
     public class QueryBuilder
     {
         /// <summary>
-        /// Build an SELECT-SQL-query by a database-primary-key<pragma/>
-        /// Will build the query-string based on the <paramref name="comparisonValue"/> including serialising and escaping for SQL.<para/>
+        /// Builds an SELECT-Sql-query based on an object
         /// </summary>
-        /// <param name="handler">Method to send querys to the database</param>
-        /// <param name="primaryKey">Database comparison value</param>
-        /// <returns>Built SQL-Query</returns>
-        public static string SelectByPrimaryKey(Type classType, object comparisonValue) => SelectByPrimaryKeys(classType, comparisonValue);
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <param name="tableName">The db-table-name</param>
+        /// <returns>SELECT-Sql-query</returns>
+        public static string SelectByPrimaryKey<T>(T classObject)
+        {
+            Type classType = classObject.GetType();
+
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            // Check if 'byPrimaryKey' is possible
+            if (dbObject.primaryKeyAttributes.Count == 0) throw new InvalidOperationException($"Cannot generate SQL-Query of '{classType.Name}'. No primary-key/s!");
+            Dictionary<string, object> dbPrimaryKeys = Function.ReadFieldData(Function.ConvertToDerivedList(dbObject.primaryKeyAttributes), classObject);
+
+            return SelectByAttribute(dbObject._tableName, dbPrimaryKeys);
+        }
+
         /// <summary>
-        /// Build an SELECT-SQL-query by database-primary-keys<pragma/>
-        /// Will build the query-string based on the <paramref name="comparisonValues"/> including serialising and escaping for SQL.<para/>
+        /// Builds an SELECT-Sql-query based on an object<para/>
+        /// Object needs to have at least 1 attribute!
         /// </summary>
-        /// <param name="handler">Method to send querys to the database</param>
-        /// <param name="primaryKeys">Database comparison values (Must be the exact same amount as primary keys in class/table)</param>
-        /// <returns>Built SQL-Query</returns>
-        public static string SelectByPrimaryKeys(Type classType, params object[] comparisonValues)
+        /// <typeparam name="T"></typeparam>
+        /// <param name="tableName">The db-table-name</param>
+        /// <param name="dbAttributes">The db-attributes with dbAttribute-name and value<para/>If null is given, it will generate a default 'SELECT * FROM tableName'</param>
+        /// <returns>SELECT-Sql-query</returns>
+        public static string SelectByAttribute(string tableName, Dictionary<string, object> dbAttributes = null)
         {
-            // Check if class has attribute 'DbObject' and get the database table-name
-            if (!(classType.GetCustomAttribute(typeof(DbObject), true) is DbObject dbObjectAttribute)) throw new InvalidOperationException("Cannot generate SQL-Query of class. Missing Attribute 'DbObject'");
-            string tableName = dbObjectAttribute._tableName ?? classType.Name;    // If no alternative table-name is specified, use the class-name
-
-            // Iterate thru all properties
-            List<string> dbPrimaryKeys = new List<string>() { };
-            foreach (System.Reflection.FieldInfo fi in classType.GetRuntimeFields())
+            object[] param = new object[1];
+            if (dbAttributes != null)
             {
-                // Get primaryKey attribute from current property
-                if (fi.GetCustomAttribute(typeof(DbPrimaryKey), true) is DbPrimaryKey pkey)
-                {
-                    string dbAttributeName = pkey._attributeName ?? fi.Name;     // If no alternative attribute-name is specified, use the property-name
-                    dbPrimaryKeys.Add(dbAttributeName);
-                }
+                // Build where statements with primaryKey/s
+                param = DbFunction.BuildKeyEqualQuery(dbAttributes, " AND ");
             }
 
-            if (comparisonValues.Length != dbPrimaryKeys.Count) throw new InvalidOperationException("Primary-key number of class/table and number of comparison values is not equal!"); 
-
-
-            object[] param = new object[comparisonValues.Length * 2];
-            for (int i = 0, c = 0; c < param.Length; i++, c += 2)
-            {
-                string sql_string = "";
-
-                if (i == 0) sql_string += $"SELECT * FROM {tableName} WHERE ";
-                else sql_string += " AND ";
-                sql_string += $"{dbPrimaryKeys[i]}=";
-
-                param[c] = sql_string;
-                param[c + 1] = comparisonValues[i];
-            }
+            string sqlCmd = $"SELECT * FROM {tableName}";
+            // Add SQL-command part
+            if (dbAttributes != null)
+                param[0] = $"{sqlCmd} WHERE {param[0]}";
+            else
+                param[0] = sqlCmd;
 
+            // Build and return the query
             return BuildQuery(param);
         }
 
+        /// <summary>
+        /// Builds an UPDATE-Sql-query based on an object<para/>
+        /// Object needs to have at least 1 primary-key!
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <returns>UPDATE-Sql-query</returns>
+        public static string UpdateByPrimaryKey<T>(T classObject)
+        {
+            Type classType = classObject.GetType();
+
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            // Check if 'byPrimaryKey' is possible
+            if (dbObject.primaryKeyAttributes.Count == 0) throw new InvalidOperationException($"Cannot generate SQL-Query of '{classType.Name}'. No primary-key/s!");
+            Dictionary<string, object> dbPrimaryKeys = Function.ReadFieldData(Function.ConvertToDerivedList(dbObject.primaryKeyAttributes), classObject);
+            Dictionary<string, object> dbForeignKeys = Function.ReadFieldData(Function.ConvertToDerivedList(dbObject.foreignKeyAttributes), classObject);
+            Dictionary<string, object> dbAttributes = Function.ReadFieldData(Function.ConvertToDerivedList(dbObject.attributeAttributes), classObject);
+
+            // Add foreign-keys to attributes
+            foreach (KeyValuePair<string, object> dbForeignKey in dbForeignKeys)
+            {
+                dbAttributes.Add(dbForeignKey.Key, dbForeignKey.Value);
+            }
+
+            // Build set-parameters
+            object[] paramSet = DbFunction.BuildKeyEqualQuery(dbAttributes, ", ");
+            // Add SQL-command part
+            paramSet[0] = $"UPDATE {dbObject._tableName} SET "+ paramSet[0];
+
+            // Build where-parameters
+            object[] paramWhere = DbFunction.BuildKeyEqualQuery(dbPrimaryKeys, " AND ");
+            // Add SQL-command part
+            paramWhere[0] = " WHERE "+ paramWhere[0];
+
+            // Build and return the query
+            return BuildQuery(paramSet, paramWhere);
+        }
+
+        /// <summary>
+        /// Builds an DELETE-Sql-query based on an object<para/>
+        /// Object needs to have at least 1 primary-key!
+        /// </summary>
+        /// <typeparam name="T"></typeparam>
+        /// <param name="classObject">Given object (marked with Db-attributes)</param>
+        /// <returns>DELETE-Sql-query</returns>
+        public static string DeleteByPrimaryKey<T>(T classObject)
+        {
+            Type classType = classObject.GetType();
+
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            // Check if 'byPrimaryKey' is possible
+            if (dbObject.primaryKeyAttributes.Count == 0) throw new InvalidOperationException($"Cannot generate SQL-Query of '{classType.Name}'. No primary-key/s!");
+            Dictionary<string, object> dbPrimaryKeys = Function.ReadFieldData(Function.ConvertToDerivedList(dbObject.primaryKeyAttributes), classObject);
+
+            // Build and return the query
+            return DeleteByAttribute(dbObject._tableName, dbPrimaryKeys);
+        }
+
+        public static string DeleteByAttribute(string tableName, Dictionary<string, object> dbAttributes = null)
+        {
+            object[] param = new object[1];
+            if (dbAttributes != null)
+            {
+                // Build where statements with primaryKey/s
+                param = DbFunction.BuildKeyEqualQuery(dbAttributes, " AND ");
+            }
+
+            string sqlCmd = $"DELETE FROM {tableName}";
+            // Add SQL-command part
+            if (dbAttributes != null)
+                param[0] = $"{sqlCmd} WHERE {param[0]}";
+            else
+                param[0] = sqlCmd;
+
+            // Build and return the query
+            return BuildQuery(param);
+        }
+
+       
+
+
 
         /// <summary>
         /// Build an SQL-query<para/>
         /// Will build the query-string based on the <paramref name="param"/>s including serialising and escaping for SQL.<para/>
+        /// (Supported-Types: null, string, byte, int, float, double, DateTime, Guid)
         /// </summary>
         /// <param name="param">Params with alternating query-parts and objects beginning with a query-part
-        /// <para/>Example: "SELECT * FROM table WHERE id=", id, " AND name=", name</param>
+        /// <para/>Example: "SELECT * FROM table WHERE id=", id, " AND name=", name<para/>
+        /// Info: Any object[] will be opened recursively and added as <paramref name="param"/> accordingly!
+        /// </param>
         public static string BuildQuery(params object[] param)
         {
-            // Convert array to list and add object[] to it accordingly
+            // Convert array to list and add object[] to it recursively
             List<object> paramz = new List<object>() { };
-            foreach (object obj in param)
-            {
-                if (!(obj is object[]))
-                    paramz.Add(obj);
-                else
-                {
-                    foreach (object obj2 in (object[])obj)
-                    {
-                        paramz.Add(obj2);
-                    }
-                }
-            }
+            Function.RecursiveParameterCopying(ref paramz, (object[])param);
 
             string query = "";
             for (int i = 0; i < paramz.Count; i++)
@@ -89,33 +163,9 @@ namespace eu.railduction.netcore.dll.Database_Attribute_System
                 if (i % 2 == 0) query += paramz[i];  // Every 'even' count will just add
                 else       // Every 'uneven' count will handle param as passed variable    
                 {
-                    string paramString = "";
-                    if (paramz[i] == null)            // Handle null
-                    {
-                        paramString = "null";
-                    }
-                    else if (paramz[i].GetType() == typeof(string))       // Handle strings
-                    {
-                        paramString = "'" + Function.SqlEscape((string)paramz[i]) + "'";  // wrap in sql-brackets and escape sql, if any
-                    }
-                    else if (paramz[i].GetType() == typeof(int) || paramz[i].GetType() == typeof(float) || paramz[i].GetType() == typeof(double))  // Handle int, float & double
-                    {
-                        paramString = paramz[i].ToString().Replace(",", ".");    // just format to string and form comma to sql-comma
-                    }
-                    else if (paramz[i].GetType() == typeof(DateTime))        // Handle DateTime
-                    {
-                        DateTime dateTime = (DateTime)paramz[i];
-                        paramString = "'" + Function.SqlSerialise(dateTime) + "'";     // wrap in sql-brackets and convert to sql-datetime
-                    }
-                    else if (paramz[i].GetType() == typeof(Guid))        // Handle DateTime
-                    {
-                        string guid = ((Guid)paramz[i]).ToString();  // Get Guid as string
-                        paramString = "'" + guid + "'";                 // wrap in sql-brackets
-                    }
-                    else        // Unknown type in params
-                    {
-                        throw new Exception($"Error in query-builder: Type '{paramz[i].GetType().ToString()}' cannot be used!");
-                    }
+                    string paramString = Function.SqlSerialise(paramz[i]);
+                    if(paramString == null)        // Unknown type in params
+                        throw new Exception($"Error in query-builder. Type '{paramz[i].GetType().ToString()}' cannot be serialised!");
 
                     // Add formed param to query
                     query += paramString;

Database-Attribute_System/internal/DbFunction.cs

@@ -0,0 +1,31 @@
+using eu.railduction.netcore.dll.Database_Attribute_System.Attributes;
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace eu.railduction.netcore.dll.Database_Attribute_System
+{
+    class DbFunction
+    {
+        internal static object[] BuildKeyEqualQuery(Dictionary<string, object> keysets, string seperator)
+        {
+            object[] param = new object[keysets.Count * 2];
+            int c = 0;
+            foreach (KeyValuePair<string, object> keyset in keysets)
+            {
+                string sql_string = "";
+
+                if (c != 0) sql_string += seperator;
+                sql_string += $"{keyset.Key}=";
+
+                param[c] = sql_string;
+                param[c + 1] = keyset.Value;
+
+                c += 2;
+            }
+
+            return param;
+        }
+    }
+}

Database-Attribute_System/internal/Function.cs

@@ -0,0 +1,156 @@
+using eu.railduction.netcore.dll.Database_Attribute_System.Attributes;
+using System;
+using System.Collections.Generic;
+using System.Reflection;
+using System.Text;
+
+namespace eu.railduction.netcore.dll.Database_Attribute_System
+{
+    internal class Function
+    {
+        public static string SqlEscape(string str)
+        {
+            string str_cpy = str.Replace(@"'", @"\'");
+            return str_cpy;
+        }
+
+        public static string SqlSerialise(DateTime dt, string format = "yyyy-MM-dd HH:mm:ss")
+        {
+            return dt.ToString(format);
+        }
+
+        // Recursive object[] copying
+        internal static void RecursiveParameterCopying(ref List<object> paramz, object[] objects)
+        {
+            foreach (object obj in objects)
+            {
+                if (!(obj is object[]))
+                    paramz.Add(obj);
+                else
+                    RecursiveParameterCopying(ref paramz, (object[])obj);
+            }
+        }
+
+        internal static List<BaseAttribute> ConvertToDerivedList(List<DbPrimaryKey> list)
+        {
+            List<BaseAttribute> derivedList = new List<BaseAttribute>() { };
+            foreach (BaseAttribute key in list)
+            {
+                derivedList.Add(key);
+            }
+            return derivedList;
+        }
+        internal static List<BaseAttribute> ConvertToDerivedList(List<DbAttribute> list)
+        {
+            List<BaseAttribute> derivedList = new List<BaseAttribute>() { };
+            foreach (BaseAttribute key in list)
+            {
+                derivedList.Add(key);
+            }
+            return derivedList;
+        }
+        internal static List<BaseAttribute> ConvertToDerivedList(List<DbForeignKey> list)
+        {
+            List<BaseAttribute> derivedList = new List<BaseAttribute>() { };
+            foreach (BaseAttribute key in list)
+            {
+                derivedList.Add(key);
+            }
+            return derivedList;
+        }
+
+        internal static Dictionary<string, object> ReadFieldData<T>(List<BaseAttribute> fieldAttributes, T classObject)
+        {
+            Dictionary<string, object> fieldData = new Dictionary<string, object>() { };
+
+            foreach (BaseAttribute attribute in fieldAttributes)
+            {
+                // Read the data and add it
+                fieldData.Add(
+                    attribute._attributeName,
+                    attribute.parentField.GetValue(classObject)
+                    );
+            }
+
+            return fieldData;   // Return the data
+        }
+
+        internal static void ConvertAttributeToDbAttributes(Type classType, Dictionary<string, object> attributeNameAndValues)
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            foreach (KeyValuePair<string, object> attributeNameAndValue in attributeNameAndValues)
+            {
+                bool nameFound = false;
+                foreach (BaseAttribute baseAttribute in dbObject.baseAttributes)
+                {
+                    if (attributeNameAndValue.Key.ToLower() == baseAttribute.parentField.Name.ToLower())
+                    {
+                        attributeNameAndValues.Remove(attributeNameAndValue.Key);
+
+                        attributeNameAndValues.Add(baseAttribute._attributeName, attributeNameAndValue.Value);
+
+                        nameFound = true;
+                        break;
+                    }
+                }
+
+                if (!nameFound) throw new InvalidOperationException($"{attributeNameAndValue.Key} has no classField!");
+            }
+        }
+        internal static void ConvertAttributeToDbAttributes(Type classType, List<string> attributeNames)
+        {
+            // Read dbObject-attribute
+            DbObject dbObject = ClassAction.Init(classType);
+
+            for(int i=0; i< dbObject.baseAttributes.Count; i++)
+            {
+                bool nameFound = false;
+                foreach (BaseAttribute baseAttribute in dbObject.baseAttributes)
+                {
+                    if(attributeNames[i].ToLower() == baseAttribute.parentField.Name.ToLower())
+                    {
+                        attributeNames[i] = baseAttribute._attributeName;
+
+                        nameFound = true;
+                        break;
+                    }
+                }
+
+                if (!nameFound) throw new InvalidOperationException($"{attributeNames[i]} has no classField!");
+            }
+        }
+
+
+        public static string SqlSerialise(object obj)
+        {
+            if (obj == null)            // Handle null
+            {
+                return "null";
+            }
+            else if (obj.GetType() == typeof(string))       // Handle strings
+            {
+                return "'" + SqlEscape((string)obj) + "'";  // wrap in sql-brackets and escape sql, if any
+            }
+            else if (obj.GetType() == typeof(byte) || obj.GetType() == typeof(int) || obj.GetType() == typeof(float) || obj.GetType() == typeof(double))  // Handle int, float & double
+            {
+                return obj.ToString().Replace(",", ".");    // just format to string and form comma to sql-comma
+            }
+            else if (obj.GetType() == typeof(DateTime))        // Handle DateTime
+            {
+                DateTime dateTime = (DateTime)obj;
+                return "'" + SqlSerialise(dateTime) + "'";     // wrap in sql-brackets and convert to sql-datetime
+            }
+            else if (obj.GetType() == typeof(Guid))        // Handle DateTime
+            {
+                string guid = ((Guid)obj).ToString();  // Get Guid as string
+                return "'" + guid + "'";                 // wrap in sql-brackets
+            }
+            else
+            {
+                return null;
+            }
+        }
+    }
+}