diff --git a/src/QueryBuilder.php b/src/QueryBuilder.php
index b1632f2..349ac6d 100644
--- a/src/QueryBuilder.php
+++ b/src/QueryBuilder.php
@@ -14,7 +14,7 @@ class QueryBuilder
     protected ?int $offset;
     protected string $raw_query;
 
-    public function __construct($table, $pk)
+    public function __construct($table, $pk = "id")
     {
         $this->table = $table;
         $this->pk = $pk;
@@ -83,6 +83,12 @@ class QueryBuilder
         return $this;
     }
 
+    public function whereRaw(string $raw)
+    {
+        $this->wheres[] = $raw;
+        return $this;
+    }
+
     public function find($id): mixed
     {
         $this->reset();
@@ -153,12 +159,24 @@ class QueryBuilder
         $ret->setQuery("");
         $ret->setData([]);
 
+        if (count($this->columns) == 0) {
+            $this->columns("*");
+        }
+
         $columns = implode(",", $this->columns);
         $where = "";
         foreach ($this->wheres as $expression) {
-            $sw = $expression->raw();
-            $ret->addData($expression->getValue());
-            if ($where != "") {
+            $sw = "";
+            if ($expression instanceof Expression) {
+                $sw = $expression->raw();
+                $ret->addData($expression->getValue());
+            }
+            if ($expression instanceof string) {
+                if (trim($expression) !== "") {
+                    $sw = "(" . $expression  . ")";
+                }
+            }
+            if ($where != "" && $sw != "") {
                 $where .= " AND ";
             }
             $where .= $sw;
diff --git a/tests/DbTest.php b/tests/DbTest.php
index 90762eb..fa26128 100644
--- a/tests/DbTest.php
+++ b/tests/DbTest.php
@@ -23,7 +23,7 @@ test("insert row",function () {
 });
 
 test("querybuilder", function() {
-    $qb = new QueryBuilder("test","id");
+    $qb = new QueryBuilder("test");
     $row = $qb->find(1);
 
     expect($row)->toBeObject();
@@ -41,6 +41,16 @@ test("querybuilder", function() {
 
     expect($rows)->toBeArray();
     expect(count($rows))->toBe(0);
+
+    $qb->reset();
+    $rows = $qb->whereRaw("id = 1")->columns("*")->get();
+    expect($rows)->toBeArray();
+    expect(count($rows))->toBe(1);
+
+    $qb->reset();
+    $rows = $qb->whereRaw("id = 1")->get();
+    expect($rows)->toBeArray();
+    expect(count($rows))->toBe(1);
 });
 
 test("update row", function() {