How to Pass Variable into a MySQL Stored Procedure from PHP - php

Question

I have the following stored procedure:
proc_main:begin
declare done tinyint unsigned default 0;
declare dpth smallint unsigned default 0;
create temporary table hier(
AGTREFERRER int unsigned,
AGTNO int unsigned,
depth smallint unsigned default 0
)engine = memory;
insert into hier values (p_agent_id, p_agent_id, dpth);
/* http://dev.mysql.com/doc/refman/5.0/en/temporary-table-problems.html */
create temporary table tmp engine=memory select * from hier;
while done <> 1 do
if exists( select 1 from agents a inner join hier on a.AGTREFERRER = hier.AGTNO and hier.depth = dpth) then
insert into hier
select a.AGTREFERRER, a.AGTNO, dpth + 1 from agents a
inner join tmp on a.AGTREFERRER = tmp.AGTNO and tmp.depth = dpth;
set dpth = dpth + 1;
truncate table tmp;
insert into tmp select * from hier where depth = dpth;
else
set done = 1;
end if;
end while;
select
a.AGTNO,
a.AGTLNAME as agent_name,
if(a.AGTNO = b.AGTNO, null, b.AGTNO) as AGTREFERRER,
if(a.AGTNO = b.AGTNO, null, b.AGTLNAME) as parent_agent_name,
hier.depth,
a.AGTCOMMLVL
from
hier
inner join agents a on hier.AGTNO = a.AGTNO
inner join agents b on hier.AGTREFERRER = b.AGTNO
order by
-- dont want to sort by depth but by commission instead - i think ??
-- hier.depth, hier.agent_id;
a.AGTCOMMLVL desc;
drop temporary table if exists hier;
drop temporary table if exists tmp;
end proc_main
While the function does its job well - it only currently allows sorting via AGTCOMMLVL descending order. The stored procedure's purpose is to match a memberID with their parentID and associated COMMLVL. Once paired appropriately,I use the memberID in a second query to return information about that particular member.
I would like to be able to sort by any number of filters but have the following problems:
I can't seem to find a way to pass a variable into the stored procedure altering its sorting by field.
Even if I could - the sort may actually only contain data from the second query (such as first name, last name, etc)
Running a sort in the second query does nothing even though syntax is correct - it always falls back to the stored procedure's sort.
any ideas?
EDIT
My php uses mysqli with code:
$sql = sprintf("call agent_hier2(%d)", $agtid);
$resulta = $mysqli->query($sql, MYSQLI_STORE_RESULT) or exit(mysqli_error($mysqli));

Answer 1

If you want to sort by input parameter of the stored procedure, you need to use Prepared staments
For example,
DELIMITER //
CREATE PROCEDURE `test1`(IN field_name VARCHAR(40) )
BEGIN
SET #qr = CONCAT ("SELECT * FROM table_name ORDER BY ", field_name);
PREPARE stmt FROM #qr;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
END //

Answer 2

$stmt = $dbh->prepare("CALL sp_takes_string_returns_string(?)");
$value = 'hello';
$stmt->bindParam(1, $value, PDO::PARAM_STR|PDO::PARAM_INPUT_OUTPUT, 4000);
// call the stored procedure
$stmt->execute();
print "procedure returned $value\n";

Answer 3

This also works in Mysql 5.6
DELIMITER //
CREATE PROCEDURE `test1`(IN field_name VARCHAR(40) )
BEGIN
"SELECT * FROM table_name ORDER BY ", field_name);
END //