SELECT 
IF(type=='Y',approveby,nonapproveby)  AS name , topic 
FROM article  
LIMIT 0,10

SELECT
CASE WHEN (type=='Y') THEN approveby
         WHEN (type=='N') THEN nonapproveby
END AS name , topic
FROM article  
LIMIT 0,10

for ($a=0;$a=count($array_name);$a++) {	
	do some thing...
}

$count=count($array_name);
for ($a=0;$a=$count;$a++) {	
	do some thing...
}