Fixes #13467: `yii\data\ActiveDataProvider` no longer queries models if models count is zero

framework/CHANGELOG.md

@@ -18,6 +18,7 @@ Yii Framework 2 Change Log
 - Bug #13592: Fixes Oracle’s `yii\db\oci\Schema::setTransactionIsolationLevel()` (sergeymakinen)
 - Bug #13594: Fixes insufficient quoting in `yii\db\QueryBuilder::prepareInsertSelectSubQuery()` (sergeymakinen)
 - Enh #13576: Added support of `srcset` to `yii\helpers\Html::img()` (Kolyunya)
+- Enh #13467: `yii\data\ActiveDataProvider` no longer queries models if models count is zero (kLkA, Kolyunya)
 
 
 2.0.11.2 February 08, 2017

framework/data/ActiveDataProvider.php

@@ -104,6 +104,9 @@ class ActiveDataProvider extends BaseDataProvider
         $query = clone $this->query;
         if (($pagination = $this->getPagination()) !== false) {
             $pagination->totalCount = $this->getTotalCount();
+            if ($pagination->totalCount === 0) {
+                return [];
+            }
             $query->limit($pagination->getLimit())->offset($pagination->getOffset());
         }
         if (($sort = $this->getSort()) !== false) {

tests/framework/data/ActiveDataProviderTest.php

@@ -7,12 +7,14 @@
 
 namespace yiiunit\framework\data;
 
+use yii\base\InvalidCallException;
 use yii\data\ActiveDataProvider;
 use yii\db\Query;
 use yiiunit\data\ar\ActiveRecord;
 use yiiunit\data\ar\Customer;
 use yiiunit\data\ar\Item;
 use yiiunit\framework\db\DatabaseTestCase;
+use yiiunit\framework\db\UnqueryableQueryMock;
 use yiiunit\data\ar\Order;
 
 /**
@@ -177,4 +179,23 @@ abstract class ActiveDataProviderTest extends DatabaseTestCase
         $provider->refresh();
         $this->assertEquals(2, count($provider->getModels()));
     }
+
+    public function testDoesNotPerformQueryWhenHasNoModels()
+    {
+        $query = new UnqueryableQueryMock;
+        $provider = new ActiveDataProvider([
+            'db' => $this->getConnection(),
+            'query' => $query->from('order')->where('0=1'),
+        ]);
+        $pagination = $provider->getPagination();
+        $this->assertEquals(0, $pagination->getPageCount());
+
+        try {
+            $this->assertCount(0, $provider->getModels());
+        } catch (InvalidCallException $exception) {
+            $this->fail('An excessive models query was executed.');
+        }
+
+        $this->assertEquals(0, $pagination->getPageCount());
+    }
 }

tests/framework/db/UnqueryableQueryMock.php

@@ -0,0 +1,25 @@
+<?php
+
+namespace yiiunit\framework\db;
+
+use yii\base\InvalidCallException;
+use yii\db\Query;
+
+class UnqueryableQueryMock extends Query
+{
+    /**
+     * @inheritdoc
+     */
+    public function one($db = null)
+    {
+        throw new InvalidCallException();
+    }
+
+    /**
+     * @inheritdoc
+     */
+    public function all($db = null)
+    {
+        throw new InvalidCallException();
+    }
+}