QueryBuilder multiply and divide support

src/Query/Builder.php

@@ -890,6 +890,33 @@ public function decrementEach(array $columns, array $extra = [], array $options
         return $this->incrementEach($decrement, $extra, $options);
     }
 
+    /** @inheritdoc */
+    public function multiply($column, $amount = 1, array $extra = [], array $options = [])
+    {
+        $query = ['$mul' => [(string) $column => $amount]];
+
+        if (! empty($extra)) {
+            $query['$set'] = $extra;
+        }
+
+        // Protect
+        $this->where(function ($query) use ($column) {
+            $query->where($column, 'exists', false);
+
+            $query->orWhereNotNull($column);
+        });
+
+        $options = $this->inheritConnectionOptions($options);
+
+        return $this->performUpdate($query, $options);
+    }
+
+    /** @inheritdoc */
+    public function divide($column, $amount = 1, array $extra = [], array $options = [])
+    {
+        return $this->multiply($column, 1 / $amount, $extra, $options);
+    }
+
     /** @inheritdoc */
     public function pluck($column, $key = null)
     {

tests/QueryBuilderTest.php

@@ -1052,6 +1052,55 @@ public function testIncrement()
         $this->assertEquals(1, $user->age);
     }
 
+    public function testMultiplyAndDivide()
+    {
+        DB::table('users')->insert([
+            ['name' => 'John Doe', 'salary' => 88000, 'note' => 'senior'],
+            ['name' => 'Jane Doe', 'salary' => 64000, 'note' => 'junior'],
+            ['name' => 'Robert Roe', 'salary' => null],
+            ['name' => 'Mark Moe'],
+        ]);
+
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(88000, $user->salary);
+
+        DB::table('users')->where('name', 'John Doe')->multiply('salary');
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(88000, $user->salary);
+
+        DB::table('users')->where('name', 'John Doe')->divide('salary');
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(88000, $user->salary);
+
+        DB::table('users')->where('name', 'John Doe')->multiply('salary', 2);
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(176000, $user->salary);
+
+        DB::table('users')->where('name', 'John Doe')->divide('salary', 2);
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(88000, $user->salary);
+
+        DB::table('users')->where('name', 'Jane Doe')->multiply('salary', 10, ['note' => 'senior']);
+        $user = DB::table('users')->where('name', 'Jane Doe')->first();
+        $this->assertEquals(640000, $user->salary);
+        $this->assertEquals('senior', $user->note);
+
+        DB::table('users')->where('name', 'John Doe')->divide('salary', 2, ['note' => 'junior']);
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(44000, $user->salary);
+        $this->assertEquals('junior', $user->note);
+
+        DB::table('users')->multiply('salary');
+        $user = DB::table('users')->where('name', 'John Doe')->first();
+        $this->assertEquals(44000, $user->salary);
+        $user = DB::table('users')->where('name', 'Jane Doe')->first();
+        $this->assertEquals(640000, $user->salary);
+        $user = DB::table('users')->where('name', 'Robert Roe')->first();
+        $this->assertNull($user->salary);
+        $user = DB::table('users')->where('name', 'Mark Moe')->first();
+        $this->assertEquals(0, $user->salary);
+    }
+
     public function testProjections()
     {
         DB::table('items')->insert([