Add empty Sort Key support (#36)

* Add empty sort key support & test

Author: miguilimzero

README.md

@@ -306,6 +306,16 @@ Schema::create('table', function (Blueprint $table) {
 });
 ```
 
+However, you may want to tune it without setting a column as sort key. You can do that by creating an empty `sortKey` definition:
+
+```php
+Schema::create('table', function (Blueprint $table) {
+    $table->string('name');
+
+    $table->sortKey()->with(['columnstore_segment_rows' => 100000]);
+});
+```
+
 ### Unique Keys
 
 You can add an `unique key` to your tables using the standalone `unique` method, or fluently by appending `unique` to the column definition.

src/Schema/Blueprint/ModifiesIndexes.php

@@ -23,7 +23,7 @@ public function shardKey($columns)
      * @param $direction
      * @return \Illuminate\Support\Fluent
      */
-    public function sortKey($columns, $direction = 'asc')
+    public function sortKey($columns = null, $direction = 'asc')
     {
         $command = $this->indexCommand('sortKey', $columns, 'sortKeyDummyName');
         $command->direction = $direction;

tests/Hybrid/CreateTable/SortKeysTest.php

@@ -168,6 +168,20 @@ public function it_adds_a_sort_key_with_with_statement()
         );
     }
 
+    /** @test */
+    public function it_adds_an_empty_sort_key_with_with_statement()
+    {
+        $blueprint = $this->createTable(function (Blueprint $table) {
+            $table->string('name');
+            $table->sortKey()->with(['columnstore_segment_rows' => 100000]);
+        });
+
+        $this->assertCreateStatement(
+            $blueprint,
+            'create table `test` (`name` varchar(255) not null, sort key() with (columnstore_segment_rows=100000))'
+        );
+    }
+
     /** @test */
     public function it_adds_a_sort_key_fluent_with_with_statement()
     {