Merge branch 'developer'

src/Query/Sql/Exists.php

@@ -0,0 +1,34 @@
+<?php namespace ClanCats\Hydrahon\Query\Sql;
+
+/**
+ * Exists query 
+ * 
+ * Allows building queries like "SELECT EXISTS(select * from showtimes) as hasShows"
+ **
+ * @package Hydrahon
+ * @copyright 2015 Mario Döring
+ */
+
+use ClanCats\Hydrahon\BaseQuery;
+
+class Exists extends BaseQuery
+{
+ /**
+ * The select query we want to check if 
+ * any results exists
+ * 
+ * @var Select
+ */
+ protected $select = null;
+
+ /**
+ * Sets the select query
+ * 
+ * @param Select $select
+ * @return void
+ */
+ public function setSelect(Select $select)
+ {
+ $this->select = $select;
+ }
+}

src/Query/Sql/Select.php

@@ -630,4 +630,27 @@ public function avg($field)
  {
  return $this->column(new Func('avg', $field));
  }
+
+ /** 
+ * Do any results of this query exist?
+ * 
+ * @return bool
+ */
+ public function exists()
+ {
+ $existsQuery = new Exists($this);
+
+ // set the current select for the exists query
+ $existsQuery->setSelect($this);
+
+ // run the callbacks to retirve the results
+ $result = $existsQuery->executeResultFetcher();
+
+ if (isset($result[0]['exists']))
+ {
+ return (bool) $result[0]['exists'];
+ }
+
+ return false;
+ }
 }

src/Translator/Mysql.php

@@ -19,6 +19,7 @@
 use ClanCats\Hydrahon\Query\Sql\Drop;
 use ClanCats\Hydrahon\Query\Sql\Truncate;
 use ClanCats\Hydrahon\Query\Sql\Func;
+use ClanCats\Hydrahon\Query\Sql\Exists;
 
 class Mysql implements TranslatorInterface
 {
@@ -86,6 +87,10 @@ public function translate(BaseQuery $query)
  {
  $queryString = $this->translateTruncate();
  }
+ elseif ($query instanceof Exists)
+ {
+ $queryString = $this->translateExists();
+ }
  // everything else is wrong
  else
  {
@@ -683,4 +688,25 @@ protected function translateTruncate()
  {
  return 'truncate table ' . $this->escapeTable() .';';
  }
+
+ /**
+ * Translate the exists querry
+ *
+ * @return string
+ */
+ protected function translateExists()
+ {
+ $translator = new static;
+
+ // translate the subselect
+ list($subQuery, $subQueryParameters) = $translator->translate($this->attr('select'));
+
+ // merge the parameters
+ foreach($subQueryParameters as $parameter)
+ {
+ $this->addParameter($parameter);
+ }
+
+ return 'select exists(' . $subQuery .') as `exists`';
+ }
 }

tests/Translator/Mysql.php

@@ -679,4 +679,34 @@ public function testAvg()
  return $q->table('test')->select()->avg('views');
  });
  }
+
+ /**
+ * mysql grammar tests
+ */
+ public function testExists()
+ {
+ $this->assertQueryExecution(array(array('exists' => 1)), true, 'select exists(select * from `test`) as `exists`', array(), function($q)
+ {
+ return $q->table('test')->select()->exists();
+ });
+
+ // no results
+ $this->assertQueryExecution(array(array('exists' => 0)), false, 'select exists(select * from `test`) as `exists`', array(), function($q)
+ {
+ return $q->table('test')->select()->exists();
+ });
+
+ // with some statements
+ $this->assertQueryExecution(array(array('exists' => 0)), false, 'select exists(select * from `test` where ( `a` = ? or `c` = ? )) as `exists`', array('b', 'd'), function($q)
+ {
+ return $q->table('test')
+ ->select()
+ ->where(function( $q )
+ {
+ $q->where('a', 'b');
+ $q->orWhere('c', 'd');
+ })
+ ->exists();
+ });
+ }
 }