diff --git a/Controller/ApiPurchaseController.php b/Controller/ApiPurchaseController.php
index f78684e..9770570 100755
--- a/Controller/ApiPurchaseController.php
+++ b/Controller/ApiPurchaseController.php
@@ -279,7 +279,7 @@ final class ApiPurchaseController extends Controller
             );
         } catch (\Throwable $t) {
             $response->header->status = RequestStatusCode::R_400;
-            $this->app->logger?->error($t->getMessage());
+            $this->app->logger->error($t->getMessage());
         }
 
         $this->createStandardUpdateResponse($request, $response, $bill);
diff --git a/Controller/BackendController.php b/Controller/BackendController.php
index 131a3d3..425ba92 100755
--- a/Controller/BackendController.php
+++ b/Controller/BackendController.php
@@ -81,7 +81,7 @@ final class BackendController extends Controller
             ->limit(25)
             ->paginate(
                 'id',
-                $request->getData('ptype'),
+                $request->getDataString('ptype'),
                 $request->getDataInt('offset')
             )
             ->execute();
@@ -487,7 +487,7 @@ final class BackendController extends Controller
             ->limit(25)
             ->paginate(
                 'id',
-                $request->getData('ptype'),
+                $request->getDataString('ptype'),
                 $request->getDataInt('offset')
             )
             ->executeGetArray();
diff --git a/Models/PurchaseBillMapper.php b/Models/PurchaseBillMapper.php
index 9c51df8..922acc0 100755
--- a/Models/PurchaseBillMapper.php
+++ b/Models/PurchaseBillMapper.php
@@ -415,10 +415,9 @@ final class PurchaseBillMapper extends BillMapper
         ORDER BY year ASC, month ASC;
         SQL;
 
-        $query  = new Builder(self::$db);
-        $result = $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
+        $query = new Builder(self::$db);
 
-        return $result ?? [];
+        return $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
     }
 
     /**
diff --git a/Models/SalesBillMapper.php b/Models/SalesBillMapper.php
index bdeb728..452c678 100755
--- a/Models/SalesBillMapper.php
+++ b/Models/SalesBillMapper.php
@@ -473,10 +473,9 @@ final class SalesBillMapper extends BillMapper
         ORDER BY item, year ASC, month ASC;
         SQL;
 
-        $query  = new Builder(self::$db);
-        $result = $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
+        $query = new Builder(self::$db);
 
-        return $result ?? [];
+        return $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
     }
 
     /**
@@ -502,10 +501,9 @@ final class SalesBillMapper extends BillMapper
         ORDER BY year ASC, month ASC;
         SQL;
 
-        $query  = new Builder(self::$db);
-        $result = $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
+        $query = new Builder(self::$db);
 
-        return $result ?? [];
+        return $query->raw($sql)->execute()?->fetchAll(\PDO::FETCH_ASSOC) ?? [];
     }
 
     /**