ajout méthodes random,index dans la collection, ajout clause distinct, whereNull , whereNotNull dans le querybuilder

tests/DbTest.php

@@ -64,6 +64,14 @@ test("querybuilder", function() {
     $rows = $qb->whereRaw("id = 1")->get();
     expect($rows)->toBeInstanceOf(Collection::class);
     expect(count($rows))->toBe(1);
+
+    $qb->reset();
+    $rows = $qb->distinct()->get();
+    expect(count($rows))->toBe(2);
+
+    $qb->reset();
+    $rows = $qb->whereNotNull("col1")->get();
+    expect(count($rows))->toBe(2);
 });
 
 test("order by", function(){
@@ -91,6 +99,8 @@ test("group by", function(){
     expect($rows->first()->Nb)->toBe(1);
 });
 
+
+
 test("update row", function() {
     $qb = new QueryBuilder("test","id");
     $row = $qb->find(1);
@@ -144,6 +154,22 @@ test("where array", function() {
 
 });
 
+test("is null", function(){
+    $row4 = new Model();
+    $row4->setTable("test");
+    $row4->col1 = null;
+    $row4->date1 = new \DateTime();
+    $ret4 = $row4->save();
+    expect($ret4)->toBe(true);
+
+    $qb = new QueryBuilder("test");
+    $rows = $qb->whereNull("col1")->get();
+
+    expect($rows)->toBeInstanceOf(Collection::class);
+    expect(count($rows))->toBe(1);
+    expect($rows->first()->col1)->toBe(null);
+});
+
 test("second connection", function() {
     $row = new Model();
     $row->setConnection("contwo");