php - Return some values with PDO in function -

i using pdo values of table : (table name ban)

id   word 1    1 2    2 3    3 4    4 

my function :

function retbans() { global $connect; $result = $connect->prepare("select * ban"); $result->execute(); $a = array(); while ($row = $result->fetch(pdo::fetch_assoc)){   $a = $row['word'].","; } return $a; } 

and in main php file, wanted them code :

$a = array(); $a = retbans(); $b = explode(",",$a); print_r($b); 

i wanted have :

array { [0] => 1 [1] => 2 [2] => 3 [3] => 4 } 

but , return , print_r last value (four) in array.

how can them said ?

use instead -

$a = ''; while ($row = $result->fetch(pdo::fetch_assoc)){   $a .= $row['word'].","; } 

then, can use explode function

$a = retbans(); $b = explode(",",$a); echo "<pre>"; print_r($b);