PHP data set method for building JSON format and a new array

I wrote an PHP result set and converted it into an JSON function, which can be directly called:

function RecordToJson($recordset) 
{ 
$jstr='['; 
while($rs = $recordset->Fetch()) 
{ 
//$nick = iconv("GBK",'utf-8',$rs['nick']);/* convert utf-8 coding */ 
//TODO: Traverse the result set  
$arr_keys=array_keys($rs); 
$jstr=$jstr.'{'; 
for($i=0;$i<count($arr_keys);$i+=2) 
{ 
// The database code is gbk , the encoding needs to be converted  
//TODO;iconv("GBK",'utf-8',$rs['nick']);/* convert utf-8 coding */ 
$key=iconv("GBK",'utf-8',$arr_keys[$i]);//$arr_keys[$i]; 
$value=iconv("GBK",'utf-8',$rs[$arr_keys[$i]]);//$rs[$arr_keys[$i]]; 
$jstr=$jstr.'"'.$key.'":"'.$value.'",'; 
} 
$jstr=substr($jstr,0,strlen($jstr)-1); 
$jstr=$jstr.'},'; 
} 
$jstr=substr($jstr,0,strlen($jstr)-1); 
$jstr=$jstr.']'; 
return $jstr; 
}

The default result set group of PHP has a numeric index. The following function can remove the numeric index and only keep the field index:

function RebuilderRecord($recordset) 
{ 
$row=0; 
while($rs = $recordset->Fetch()) 
{ 
//TODO: Traverse the result set  
$arr_keys=array_keys($rs); 
for($i=0;$i<count($arr_keys);$i+=2) 
{ 
$newrs[$row][$arr_keys[$i]]=$rs[$arr_keys[$i]]; 
} 
$row++; 
} 
return $newrs; 
}