Support qualified cursor (#3)

src/Processor.php

@@ -22,6 +22,18 @@ class Processor extends ArrayProcessor
 {
     use HasSnakeAliases;
 
+    /**
+     * Return comparable value from a row.
+     *
+     * @param  mixed      $row
+     * @param  string     $column
+     * @return int|string
+     */
+    protected function field($row, $column)
+    {
+        return parent::field($row, static::dropTablePrefix($column));
+    }
+
     /**
      * Slice rows, like PHP function array_slice().
      *
@@ -62,4 +74,17 @@ protected function defaultFormat($rows, array $meta, Query $query)
     {
         return new PaginationResult($rows, $meta);
     }
+
+    /**
+     * Drop table prefix on column name.
+     *
+     * @param  string $column
+     * @return string
+     */
+    protected static function dropTablePrefix($column)
+    {
+        $segments = explode('.', $column);
+
+        return end($segments);
+    }
 }

tests/MySQLGrammarTest.php

@@ -416,4 +416,42 @@ public function testDescendingBackwardExclusive()
             ) `temporary_table`
         ', $this->toSql($builder));
     }
+
+    /**
+     * @test
+     */
+    public function testQualifiedColumnOrder()
+    {
+        $cursor = ['posts.updated_at' => '', 'posts.created_at' => '', 'posts.id' => ''];
+        $builder = lampager(ORM::forTable('posts')->where_equal('posts.user_id', 2))
+            ->forward()->limit(3)
+            ->order_by_asc('posts.updated_at')
+            ->order_by_asc('posts.created_at')
+            ->order_by_asc('posts.id')
+            ->seekable()
+            ->build($cursor);
+        $this->assertSqlEquals('
+            SELECT * FROM (
+                SELECT * FROM `posts`
+                WHERE `posts`.`user_id` = ? AND (
+                  `posts`.`updated_at` = ? AND `posts`.`created_at` = ? AND `posts`.`id` < ? OR
+                  `posts`.`updated_at` = ? AND `posts`.`created_at` < ? OR
+                  `posts`.`updated_at` < ?
+                )
+                ORDER BY `posts`.`updated_at` DESC, `posts`.`created_at` DESC, `posts`.`id` DESC
+                LIMIT 1
+            ) `temporary_table`
+            UNION ALL
+            SELECT * FROM (
+                SELECT * FROM `posts`
+                WHERE `posts`.`user_id` = ? AND (
+                  `posts`.`updated_at` = ? AND `posts`.`created_at` = ? AND `posts`.`id` >= ? OR
+                  `posts`.`updated_at` = ? AND `posts`.`created_at` > ? OR
+                  `posts`.`updated_at` > ?
+                )
+                ORDER BY `posts`.`updated_at` ASC, `posts`.`created_at` ASC, `posts`.`id` ASC
+                LIMIT 4
+            ) `temporary_table`
+        ', $this->toSql($builder));
+    }
 }

tests/ProcessorTest.php

@@ -435,4 +435,30 @@ public function testDescendingBackwardExclusive()
                 ->paginate(['id' => '3', 'updated_at' => '2017-01-01 10:00:00'])
         );
     }
+
+    /**
+     * @test
+     */
+    public function testQualifiedColumnOrder()
+    {
+        $this->assertResultSame(
+            [
+                'records' => [
+                    ['id' => '3', 'updated_at' => '2017-01-01 10:00:00'],
+                    ['id' => '5', 'updated_at' => '2017-01-01 10:00:00'],
+                    ['id' => '2', 'updated_at' => '2017-01-01 11:00:00'],
+                ],
+                'has_previous' => true,
+                'previous_cursor' => ['posts.updated_at' => '2017-01-01 10:00:00', 'posts.id' => '1'],
+                'has_next' => true,
+                'next_cursor' => ['posts.updated_at' => '2017-01-01 11:00:00', 'posts.id' => '4'],
+            ],
+            lampager(ORM::for_table('posts'))
+                ->forward()->limit(3)
+                ->order_by_asc('posts.updated_at')
+                ->order_by_asc('posts.id')
+                ->seekable()
+                ->paginate(['posts.id' => '3', 'posts.updated_at' => '2017-01-01 10:00:00'])
+        );
+    }
 }