Add count select for total count queries

src/Repository.php

@@ -49,9 +49,7 @@ protected function select() : Select
      */
     protected function count() : Select
     {
-        return $this->select()->columns([
-            self::COUNT_COLUMN => new Literal('COUNT(1)')
-        ]);
+        return new Count($this->tableGateway->getTable());
     }
 
     /**
@@ -109,13 +107,13 @@ protected function fetchListEntities(Select $select) : ResultSetInterface
     }
 
     /**
-     * @param \Zend\Db\Sql\Select $select
+     * @param Count $select
      * @return int
      */
-    protected function fetchCount(Select $select)
+    protected function fetchCount(Count $select)
     {
-        $statement  = $this->tableGateway->getSql()->prepareStatementForSqlObject($select);
-        $results = $statement->execute();
+        $statement = $this->tableGateway->getSql()->prepareStatementForSqlObject($select);
+        $results   = $statement->execute();
 
         return $results->current()[self::COUNT_COLUMN];
     }

src/Select/Count.php

@@ -0,0 +1,27 @@
+<?php
+
+namespace Matters\Select;
+
+use Zend\Db\Sql\Literal;
+use Zend\Db\Sql\Select;
+
+class Count extends Select
+{
+    const COUNT_COLUMN = 'count';
+
+    /**
+     * Count constructor.
+     */
+    public function __construct($table = null)
+    {
+        parent::__construct($table);
+        parent::columns([
+            self::COUNT_COLUMN => new Literal('COUNT(1)')
+        ]);
+    }
+
+    public function columns(array $columns, $prefixColumnsWithTable = true)
+    {
+        throw new \BadMethodCallException('The columns should not be changed');
+    }
+}

tests/Select/CountTest.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace Matters\Select;
+
+use PHPUnit\Framework\TestCase;
+use Zend\Db\Adapter\Platform\Postgresql;
+
+class CountTest extends TestCase
+{
+    public function testInstance()
+    {
+        $select = (new Count())->from('carot');
+        $select->where("color = 'purple'");
+
+        $platform = new class extends Postgresql
+        {
+            public function quoteValue($value)
+            {
+                return '"'. $value .'"';
+            }
+        };
+
+        self::assertSame(
+            'SELECT COUNT(1) AS "count" FROM "carot" WHERE color = \'purple\'',
+            $select->getSqlString($platform)
+        );
+    }
+}