Index: CIconMap.php
===================================================================
--- CIconMap.php	(revision 31986)
+++ CIconMap.php	(working copy)
@@ -55,6 +55,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('iconmapids', 'sysmapids');
+
 		$sqlParts = array(
 			'select'	=> array('icon_map' => 'im.iconmapid'),
 			'from'		=> array('icon_map' => 'icon_map im'),
@@ -87,6 +89,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			$dbTable = DB::getSchema('icon_map');
 			foreach ($options['output'] as $field) {
Index: CGraphPrototype.php
===================================================================
--- CGraphPrototype.php	(revision 31986)
+++ CGraphPrototype.php	(working copy)
@@ -52,6 +52,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('graphids', 'groupids', 'itemids', 'discoveryids');
+
 		$sqlParts = array(
 			'select'	=> array('graphs' => 'g.graphid'),
 			'from'		=> array('graphs' => 'graphs g'),
@@ -98,6 +100,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+		if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['graphs']);
 
Index: CHostGroup.php
===================================================================
--- CHostGroup.php	(revision 31986)
+++ CHostGroup.php	(working copy)
@@ -44,6 +44,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('groupids', 'graphids', 'triggerids', 'maintenanceids');
+
 		$sqlParts = array(
 			'select'	=> array('groups' => 'g.groupid'),
 			'from'		=> array('groups' => 'groups g'),
@@ -98,6 +100,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $params);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['groups']);
Index: CTemplateScreenItem.php
===================================================================
--- CTemplateScreenItem.php	(revision 31986)
+++ CTemplateScreenItem.php	(working copy)
@@ -90,8 +90,13 @@
 	 * @return array|boolean Host data as array or false if error
 	 */
 	public function get(array $options = array()) {
+		$mandatory_params = array('screenitemids', 'screenids', 'hostids');
 		$options = zbx_array_merge($this->getOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// build and execute query
 		$sql = $this->createSelectQuery($this->tableName(), $options);
 		$res = DBselect($sql, $options['limit']);
Index: CUserGroup.php
===================================================================
--- CUserGroup.php	(revision 31986)
+++ CUserGroup.php	(working copy)
@@ -59,6 +59,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('usrgrpids', 'userids');
+
 		$sqlParts = array(
 			'select'	=> array('usrgrp' => 'g.usrgrpid'),
 			'from'		=> array('usrgrp' => 'usrgrp g'),
@@ -93,6 +95,10 @@
 
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['usrgrp']);
 
Index: CItem.php
===================================================================
--- CItem.php	(revision 31986)
+++ CItem.php	(working copy)
@@ -56,6 +56,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('itemids', 'groupids', 'proxyids', 'interfaceids', 'graphids', 'triggerids', 'applicationids');
+
 		$sqlParts = array(
 			'select'	=> array('items' => 'i.itemid'),
 			'from'		=> array('items' => 'items i'),
@@ -112,6 +114,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['items']);
 
Index: CGraph.php
===================================================================
--- CGraph.php	(revision 31986)
+++ CGraph.php	(working copy)
@@ -56,6 +56,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('graphids', 'groupids', 'itemids');
+
 		$sqlParts = array(
 			'select'	=> array('graphs' => 'g.graphid'),
 			'from'		=> array('graphs' => 'graphs g'),
@@ -101,6 +103,19 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+		if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+		if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['graphs']);
 
Index: CApplication.php
===================================================================
--- CApplication.php	(revision 31986)
+++ CApplication.php	(working copy)
@@ -52,6 +52,8 @@
 		$sortColumns = array('applicationid', 'name');
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('applicationids', 'groupids', 'itemids');
+
 		$sqlParts = array(
 			'select'	=> array('apps' => 'a.applicationid'),
 			'from'		=> array('applications' => 'applications a'),
@@ -93,6 +95,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+			return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
+		if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+		if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }		
+
 		// editable + PERMISSION CHECK
 		if ($userType != USER_TYPE_SUPER_ADMIN && !$options['nopermissions']) {
 			$permission = $options['editable'] ? PERM_READ_WRITE : PERM_READ_ONLY;
Index: CDService.php
===================================================================
--- CDService.php	(revision 31986)
+++ CDService.php	(working copy)
@@ -76,6 +76,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('dserviceids', 'dhostids', 'dcheckids', 'druleids');
+
 		$sqlParts = array(
 			'select'	=> array('dservices' => 'ds.dserviceid'),
 			'from'		=> array('dservices' => 'dservices ds'),
@@ -116,6 +118,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                    return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['dservices']);
 
Index: CScript.php
===================================================================
--- CScript.php	(revision 31986)
+++ CScript.php	(working copy)
@@ -54,6 +54,8 @@
 		// allowed columns for sorting
 		$sortColumns = array('scriptid', 'name');
 
+		$mandatory_params = array('scriptids', 'groupids', 'hostids', 'usrgrpids');
+
 		$sqlParts = array(
 			'select'	=> array('scripts' => 's.scriptid'),
 			'from'		=> array('scripts s'),
@@ -89,6 +91,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['scripts']);
 
Index: CTemplate.php
===================================================================
--- CTemplate.php	(revision 31986)
+++ CTemplate.php	(working copy)
@@ -46,6 +46,9 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('templateids', 'parentTemplateids', 'groupids', 'hostids',
+					  'graphids', 'itemids', 'triggerids');
+
 		$sqlParts = array(
 			'select'	=> array('templates' => 'h.hostid'),
 			'from'		=> array('hosts' => 'hosts h'),
@@ -99,6 +102,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['templates']);
 
Index: CMap.php
===================================================================
--- CMap.php	(revision 31986)
+++ CMap.php	(working copy)
@@ -66,6 +66,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('sysmapids');
+
 		$sqlParts = array(
 			'select'	=> array('sysmaps' => 's.sysmapid'),
 			'from'		=> array('sysmaps' => 'sysmaps s'),
@@ -100,6 +102,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['sysmaps']);
 
Index: CUser.php
===================================================================
--- CUser.php	(revision 31986)
+++ CUser.php	(working copy)
@@ -51,6 +51,8 @@
 		// allowed columns for sorting
 		$sortColumns = array('userid', 'alias');
 
+		$mandatory_params = array('userids', 'usrgrpids', 'mediaids', 'mediatypeids');
+
 		$sqlParts = array(
 			'select'	=> array('users' => 'u.userid'),
 			'from'		=> array('users' => 'users u'),
@@ -87,6 +89,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['users']);
 
Index: CScreen.php
===================================================================
--- CScreen.php	(revision 31986)
+++ CScreen.php	(working copy)
@@ -54,6 +54,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('screenids', 'screenitemids');
+
 		$sqlParts = array(
 			'select'	=> array('screens' => 's.screenid'),
 			'from'		=> array('screens' => 'screens s'),
@@ -88,6 +90,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['screens']);
 
Index: CGraphItem.php
===================================================================
--- CGraphItem.php	(revision 31986)
+++ CGraphItem.php	(working copy)
@@ -48,6 +48,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('graphids', 'itemids');
+
 		$sqlParts = array(
 			'select'	=> array('gitems' => 'gi.gitemid'),
 			'from'		=> array('graphs_items' => 'graphs_items gi'),
@@ -75,6 +77,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		if ($userType != USER_TYPE_SUPER_ADMIN && !$options['nopermissions']) {
 			$permission = $options['editable'] ? PERM_READ_WRITE : PERM_READ_ONLY;
Index: CEvent.php
===================================================================
--- CEvent.php	(revision 31986)
+++ CEvent.php	(working copy)
@@ -59,6 +59,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('eventids', 'groupids', 'hostids');
+
 		$sqlParts = array(
 			'select'	=> array($this->fieldId('eventid')),
 			'from'		=> array('events' => 'events e'),
@@ -109,6 +111,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		if ($userType != USER_TYPE_SUPER_ADMIN && !$options['nopermissions']) {
 			if (is_null($options['source']) && is_null($options['object'])) {
@@ -145,6 +151,10 @@
 			}
 		}
 
+		if (!is_null($options['triggerids']) && !count($options['triggerids']) && $options['object'] == EVENT_OBJECT_TRIGGER) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// nodeids
 		$nodeids = !is_null($options['nodeids']) ? $options['nodeids'] : get_current_nodeid();
 
@@ -519,7 +529,7 @@
 		}
 
 		// adding acknowledges
-		if (!is_null($options['select_acknowledges'])) {
+		if (!is_null($options['select_acknowledges']) && count($eventids)) {
 			if (is_array($options['select_acknowledges']) || str_in_array($options['select_acknowledges'], $subselectsAllowedOutputs)) {
 				$res = DBselect(
 					'SELECT a.*,u.alias'.
Index: CDHost.php
===================================================================
--- CDHost.php	(revision 31986)
+++ CDHost.php	(working copy)
@@ -76,6 +76,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('druleids', 'dhostids', 'dserviceids', 'groupids', 'hostids');
+
 		$sqlParts = array(
 			'select'	=> array('dhosts' => 'dh.dhostid'),
 			'from'		=> array('dhosts' => 'dhosts dh'),
@@ -117,6 +119,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+		    return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['dhosts']);
 
Index: CItemPrototype.php
===================================================================
--- CItemPrototype.php	(revision 31986)
+++ CItemPrototype.php	(working copy)
@@ -41,6 +41,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('itemids', 'groupids', 'discoveryids', 'graphids', 'triggerids');
+
 		$sqlParts = array(
 			'select'	=> array('items' => 'i.itemid'),
 			'from'		=> array('items' => 'items i'),
@@ -88,6 +90,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['items']);
 
Index: CMapElement.php
===================================================================
--- CMapElement.php	(revision 31986)
+++ CMapElement.php	(working copy)
@@ -56,6 +56,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('sysmapids');
+
 		$sqlParts = array(
 			'select'	=> array('sysmaps_elements' => 'se.selementid'),
 			'from'		=> array('sysmaps_elements' => 'sysmaps_elements se'),
@@ -89,6 +91,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['sysmaps_elements']);
 
Index: CTriggerPrototype.php
===================================================================
--- CTriggerPrototype.php	(revision 31986)
+++ CTriggerPrototype.php	(working copy)
@@ -52,6 +52,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('triggerids', 'groupids', 'itemids', 'applicationids', 'discoveryids');
+
 		$sqlParts = array(
 			'select'	=> array('triggers' => 't.triggerid'),
 			'from'		=> array('t' => 'triggers t'),
@@ -107,6 +109,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['triggers']);
 
Index: CScreenItem.php
===================================================================
--- CScreenItem.php	(revision 31986)
+++ CScreenItem.php	(working copy)
@@ -88,8 +88,15 @@
 	 * @return array|boolean Host data as array or false if error
 	 */
 	public function get(array $options = array()) {
+
+		$mandatory_params = array('screenitemids', 'screenids');
+
 		$options = zbx_array_merge($this->getOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }		
+
 		// build and execute query
 		$sql = $this->createSelectQuery($this->tableName(), $options);
 		$res = DBselect($sql, $options['limit']);
Index: CHostInterface.php
===================================================================
--- CHostInterface.php	(revision 31986)
+++ CHostInterface.php	(working copy)
@@ -60,6 +60,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('interfaceids', 'groupids', 'hostids', 'itemids', 'triggerids');
+
 		$sqlParts = array(
 			'select'	=> array('interface' => 'hi.interfaceid'),
 			'from'		=> array('interface' => 'interface hi'),
@@ -99,6 +101,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['interface']);
 
Index: CDiscoveryRule.php
===================================================================
--- CDiscoveryRule.php	(revision 31986)
+++ CDiscoveryRule.php	(working copy)
@@ -48,6 +48,9 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('groupids', 'itemids', 'interfaceids');
+
+
 		$sqlParts = array(
 			'select'	=> array('items' => 'i.itemid'),
 			'from'		=> array('items' => 'items i'),
@@ -92,6 +95,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+            		return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+		if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+            		return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
+		if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+            		return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['items']);
 
Index: CUserMacro.php
===================================================================
--- CUserMacro.php	(revision 31986)
+++ CUserMacro.php	(working copy)
@@ -59,6 +59,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('hostmacroids', 'groupids', 'hostids', 'templateids');
+
 		$sqlParts = array(
 			'select'	=> array('macros' => 'hm.hostmacroid'),
 			'from'		=> array('hostmacro hm'),
@@ -105,6 +107,14 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!is_null($options['globalmacro']) && !is_null($options['globalmacroids']) && !count($options['globalmacroids'])) {
+			return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		if ($userType != USER_TYPE_SUPER_ADMIN && !$options['nopermissions']) {
 			if (!is_null($options['editable']) && !is_null($options['globalmacro'])) {
Index: CHistory.php
===================================================================
--- CHistory.php	(revision 31986)
+++ CHistory.php	(working copy)
@@ -55,6 +55,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('hostids', 'itemids');
+
 		$sqlParts = array(
 			'select'	=> array('history' => 'h.itemid'),
 			'from'		=> array(),
@@ -93,6 +95,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		switch ($options['history']) {
 			case ITEM_VALUE_TYPE_LOG:
 				$sqlParts['from']['history'] = 'history_log h';
Index: CTrigger.php
===================================================================
--- CTrigger.php	(revision 31986)
+++ CTrigger.php	(working copy)
@@ -58,6 +58,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('triggerids', 'groupids', 'itemids', 'applicationids');
+
 		$fieldsToUnset = array();
 
 		$sqlParts = array(
@@ -124,6 +126,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['triggers']);
Index: CDRule.php
===================================================================
--- CDRule.php	(revision 31986)
+++ CDRule.php	(working copy)
@@ -49,6 +49,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('druleids', 'dhostids', 'dserviceids', 'dcheckids');
+
 		$sqlParts = array(
 			'select'	=> array('drules' => 'dr.druleid'),
 			'from'		=> array('drules' => 'drules dr'),
@@ -87,6 +89,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                    return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 // editable + PERMISSION CHECK
 		if (USER_TYPE_SUPER_ADMIN == $userType) {
 		}
Index: CTemplateScreen.php
===================================================================
--- CTemplateScreen.php	(revision 31986)
+++ CTemplateScreen.php	(working copy)
@@ -51,6 +51,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('screenids', 'screenitemids');
+
 		$sqlParts = array(
 			'select'	=> array('screens' => 's.screenid, s.templateid'),
 			'from'		=> array('screens' => 'screens s'),
@@ -88,6 +90,18 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['hostids']) && !count($options['hostids']) && !count($options['templateids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
+                if (!is_null($options['templateids']) && !count($options['templateids']) && !count($options['hostids'])) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['screens']);
 
Index: CWebCheck.php
===================================================================
--- CWebCheck.php	(revision 31986)
+++ CWebCheck.php	(working copy)
@@ -43,6 +43,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('httptestids', 'applicationids', 'hostids');
+
 		$sqlParts = array(
 			'select'	=> array('httptests' => 'ht.httptestid'),
 			'from'		=> array('httptest' => 'httptest ht'),
@@ -78,6 +80,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		if ($userType != USER_TYPE_SUPER_ADMIN && !$options['nopermissions']) {
 			$permission = $options['editable']?PERM_READ_WRITE:PERM_READ_ONLY;
Index: CHost.php
===================================================================
--- CHost.php	(revision 31986)
+++ CHost.php	(working copy)
@@ -73,6 +73,10 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('hostids', 'groupids', 'proxyids', 'templateids', 'interfaceids', 
+					  'itemids', 'triggerids', 'httptestids', 'graphids', 'applicationids', 
+					  'dhostids', 'dserviceids', 'maintenanceids');
+
 		$sqlParts = array(
 			'select'	=> array('hosts' => 'h.hostid'),
 			'from'		=> array('hosts' => 'hosts h'),
@@ -145,6 +149,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+			return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['hosts']);
 
Index: CUserMedia.php
===================================================================
--- CUserMedia.php	(revision 31986)
+++ CUserMedia.php	(working copy)
@@ -59,6 +59,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('mediaids', 'mediatypeids', 'usrgrpids', 'userids');
+
 		$sqlParts = array(
 			'select'	=> array('media' => 'm.mediaid'),
 			'from'		=> array('media' => 'media m'),
@@ -93,6 +95,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['media']);
 
Index: CProxy.php
===================================================================
--- CProxy.php	(revision 31986)
+++ CProxy.php	(working copy)
@@ -51,6 +51,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('proxyids');
+
 		$sqlParts = array(
 			'select'	=> array('hostid' => 'h.hostid'),
 			'from'		=> array('hosts' => 'hosts h'),
@@ -84,6 +86,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['hosts']);
 
Index: CMediatype.php
===================================================================
--- CMediatype.php	(revision 31986)
+++ CMediatype.php	(working copy)
@@ -58,6 +58,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND);
 
+		$mandatory_params = array('mediatypeids', 'mediaids', 'userids');
+
 		$sqlParts = array(
 			'select'	=> array('media_type' => 'mt.mediatypeid'),
 			'from'		=> array('media_type' => 'media_type mt'),
@@ -93,6 +95,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// permission check
 		if (USER_TYPE_SUPER_ADMIN == $userType) {
 		}
Index: CDCheck.php
===================================================================
--- CDCheck.php	(revision 31986)
+++ CDCheck.php	(working copy)
@@ -43,6 +43,8 @@
 		// allowed output options for [ select_* ] params
 		$subselectsAllowedOutputs = array(API_OUTPUT_REFER, API_OUTPUT_EXTEND, API_OUTPUT_CUSTOM);
 
+		$mandatory_params = array('dcheckids', 'druleids', 'dhostids', 'dserviceids');
+
 		$sqlParts = array(
 			'select'	=> array('dchecks' => 'dc.dcheckid'),
 			'from'		=> array('dchecks' => 'dchecks dc'),
@@ -82,6 +84,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+		       return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+		}
+
 		if (is_array($options['output'])) {
 			unset($sqlParts['select']['dchecks']);
 
Index: CMaintenance.php
===================================================================
--- CMaintenance.php	(revision 31986)
+++ CMaintenance.php	(working copy)
@@ -58,6 +58,8 @@
 		// allowed columns for sorting
 		$sortColumns = array('maintenanceid', 'name', 'maintenance_type');
 
+		$mandatory_params = array('maintenanceids', 'groupids', 'itemids');
+
 		$sqlParts = array(
 			'select'	=> array('maintenance' => 'm.maintenanceid'),
 			'from'		=> array('maintenances' => 'maintenances m'),
@@ -96,6 +98,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		$maintenanceids = array();
 		if ($userType == USER_TYPE_SUPER_ADMIN || $options['nopermissions']) {
Index: CImage.php
===================================================================
--- CImage.php	(revision 31986)
+++ CImage.php	(working copy)
@@ -56,6 +56,8 @@
 		// allowed columns for sorting
 		$sortColumns = array('imageid', 'name');
 
+		$mandatory_params = array('imageids', 'sysmapids');
+
 		$sqlParts = array(
 			'select'	=> array('images' => 'i.imageid'),
 			'from'		=> array('images' => 'images i'),
@@ -87,6 +89,10 @@
 		);
 		$options = zbx_array_merge($defOptions, $options);
 
+		if (!zbx_CheckRequires($options, $mandatory_params)) {
+                        return ($options['output'] == API_OUTPUT_COUNT) ? 0 : array();
+                }
+
 		// editable + PERMISSION CHECK
 		if (!is_null($options['editable']) && (self::$userData['type'] < USER_TYPE_ZABBIX_ADMIN)) {
 			return $result;
Index: include/func.inc.php
===================================================================
--- include/func.inc.php        (revision 31986)
+++ include/func.inc.php        (working copy)
@@ -1863,3 +1863,14 @@

        return $str;
 }
+
+function zbx_CheckRequires($options, $mandatory) {
+
+       foreach ($options as $name => $value) {
+               if (in_array($name, $mandatory) && !is_null($value) && !count($value)) {
+                       return false;
+               }
+       }
+
+       return true;
+}