Как сделать запрос в базу? (дубли в array()..)

 
$sql = "SELECT pole AS param1 FROM table1 WHERE published = 1 GROUP BY param1 ";
$result = $inDB->query($sql) ;
if ($inDB->num_rows($result)){
while($arr = $inDB->fetch_assoc($result)){
$array[] = $arr;}
}
 

 
$sql = "SELECT param1 FROM table2 WHERE published = 1 OR ... GROUP BY param1 ";
$result = $inDB->query($sql) ;
if ($inDB->num_rows($result)){
while($arr = $inDB->fetch_assoc($result)){
$array[] = $arr;}
}
 

$sql = "SELECT DISTINCT pole AS param1 FROM table1 WHERE published = 1 GROUP BY param1 ";
$sql = "SELECT DISTINCT param1 FROM table2 WHERE published = 1 OR ... GROUP BY param1 ";
 

 
$res_array = array();
foreach($array as $value){
$res_array[] = $value['param1'];
}
$res_array = array_unique($res_array); 
 

 
SELECT t1.param1 as pole
FROM table1 as t1
WHERE published = 1
UNION SELECT t2.param1 as pole
FROM table2 as t2
WHERE published = 1 OR 1=1
GROUP BY pole