Update repository, seed and service layers

DataAccessLayer/Sql/DatabaseHelper.cs

@@ -1,41 +0,0 @@
-using System;
-using System.Data;
-using Microsoft.Data.SqlClient;
-
-namespace DataAccessLayer.Sql
-{
-    public class DatabaseHelper(string connectionString)
-    {
-        public void ExecuteRawSql(string query)
-        {
-            try
-            {
-                using var connection = new SqlConnection(
-                    connectionString
-                );
-                
-                connection.Open();
-
-                using var command = new SqlCommand(query, connection);
-                
-                command.CommandType = CommandType.Text;
-
-                using var reader = command.ExecuteReader();
-                
-                while (reader.Read())
-                {
-                    for (var i = 0; i < reader.FieldCount; i++)
-                    {
-                        Console.WriteLine(
-                            $"{reader.GetName(i)}: {reader.GetValue(i)}"
-                        );
-                    }
-                }
-            }
-            catch (Exception ex)
-            {
-                Console.WriteLine($"An error occurred: {ex.Message}");
-            }
-        }
-    }
-}

DataAccessLayer/Sql/ISqlConnectionFactory.cs

@@ -0,0 +1,9 @@
+using Microsoft.Data.SqlClient;
+
+namespace DataAccessLayer.Sql
+{
+    public interface ISqlConnectionFactory
+    {
+        SqlConnection CreateConnection();
+    }
+}