feat: addded authorById

src/team4.cs

@@ -213,6 +213,41 @@ public class Team4
         }
     }
 
+    public static AuthorDto GetAuthorById(SqliteConnection conn, int authorID)
+    {
+        try
+        {
+            using (var command = conn.CreateCommand())
+            {
+                command.CommandText = @"
+                    SELECT author.ID
+                    FROM Authors author
+                    WHERE author.ID = @aid;";
+                command.Parameters.AddWithValue("@aid", authorID);
+
+                using (var reader = command.ExecuteReader())
+                {
+                    while (reader.Read())
+                    {
+                        return new AuthorDto
+                        {
+                            Id = reader.GetInt32(0),
+                            Name = reader.GetString(1),
+                            Surname = reader.GetString(2),
+                            DateOfBirth = reader.GetDateTime(3)
+                        };
+                    }
+                }
+                return null;
+            }
+        }
+        catch (Exception ex)
+        {
+            Console.WriteLine($"Error in GetAuthorById: {ex.Message}");
+            throw;
+        }
+    }
+
     public static void GetBooksBy(SqliteConnection conn)
     {
         throw new NotImplementedException();