variable not work in where clause php joomla

问题

I have function and my function works good only I do not understand this:

<?php

// $category output is 23 when I echo $category; and there is no records
->where('d.category_id = ' . (int) $category)

// also this method not work
->where('d.category_id = ' . $category)

// but this method works 
->where('d.category_id = 23')

?>

this is full code:

$category = $params->get('title');

//echo $category;

public static function getSuggested($category) {


$db    = JFactory::getDBO();
$query = $db->getQuery(true);

//$now      = $jdate->toSql();
//$nullDate = $db->quote($db->getNullDate());

$query->select('d.*');
$query->from('#__deals_deals AS d');

$query->select('c.title AS category_title');
$query->join('LEFT', '#__deals_categories AS c ON c.id = d.category_id')
->where('(d.is_market = 0 AND d.state = 1)','AND')
->where('d.category_id = 23')
->order('id DESC');

//$query->where('(d.publish_up = ' . $nullDate . ' OR d.publish_up <= ' . $query->quote($now) . ')');
//$query->where('(d.publish_down = ' . $nullDate . ' OR d.publish_down >= ' . $query->quote($now) . ')');   
$db->setQuery($query,0,10); 

$results = $db->loadObjectList();

return $results;

}

this function works good only need to get category data. this is joomla module, and this function is in helper.php file in default.php file I am get some data from this function.

I found solution:

Add in mod_suggested_deals.php

$category = (int) $params->get('fieldvalue'); 

then:

$results = modsuggested_dealsHelper::getSuggested($category);

回答1:

I found soluton for this question:

in my function I Add param $category

public static function getSuggested($category) {...}

in mod_suggested_deals.php I add code:

$category = $params->get('title');

then is code (it already was here).

$results = modsuggested_dealsHelper::getSuggested($category);

回答2:

The mistake you are doing is you are defining a variable value outside a function but calling the variable inside it. If your class is not abstract class you can use $this->category or if your class is an abstract class then use the $category variable inside of the function like this

public static function getSuggested() {

  $module = JModuleHelper::getModule('mod_yourmodulename');
  $catid = new JRegistry($module->params);
  $category = (int) $catid['title'];


$db    = JFactory::getDBO();
$query = $db->getQuery(true);

//$now      = $jdate->toSql();
//$nullDate = $db->quote($db->getNullDate());

$query->select('d.*');
$query->from('#__deals_deals AS d');

$query->select('c.title AS category_title');
$query->join('LEFT', '#__deals_categories AS c ON c.id = d.category_id')
->where('(d.is_market = 0 AND d.state = 1)','AND')
->where('d.category_id = '.$category)
->order('id DESC');

//$query->where('(d.publish_up = ' . $nullDate . ' OR d.publish_up <= ' . $query->quote($now) . ')');
//$query->where('(d.publish_down = ' . $nullDate . ' OR d.publish_down >= ' . $query->quote($now) . ')');   
$db->setQuery($query,0,10); 

$results = $db->loadObjectList();

return $results;

}

来源：https://stackoverflow.com/questions/41249364/variable-not-work-in-where-clause-php-joomla