Updating table using group by sum - mysql

Question

I have two tables. One is a detail table that contains quantity info and has the following structure
> mysql> DESCRIBE summary_finished;
+---------------+---------------+------+-----+---------+
| Field | Type | Null | Key | Default |
+---------------+---------------+------+-----+---------+
| db_id | int(11) | NO | PRI | NULL |
| finished_id | text | NO | | NULL |
| finished_name | text | NO | | NULL |
| qoh | int(11) | NO | | NULL |
| value | decimal(10,2) | NO | | NULL |
+---------------+---------------+------+-----+---------+
mysql> DESCRIBE detail_finished;
+-------------+---------------+------+-----+---------+
| Field | Type | Null | Key | Default |
+-------------+---------------+------+-----+---------+
| db_id | int(11) | NO | PRI | NULL |
| finished_id | text | NO | | NULL |
| quantity | int(11) | NO | | NULL |
| value | decimal(10,2) | NO | | NULL |
+-------------+---------------+------+-----+---------+
In detail_finished there are many items that have the same finished_id. What I am trying to accomplish is combining items that have the same finished_id and update that sum to the summary_finished.qoh field. This is what I have so far:
function set_qty($total, $finished_id){
global $connection;
$query="UPDATE summary_finished
SET qoh={$total}
WHERE finished_id='$finished_id'";
$quantity=mysql_query($query, $connection);
confirm_query($quantity);
}
$query="SELECT finished_id, SUM(quantity) FROM detail_finished GROUP BY finished_id";
$result=mysql_query($query, $connection) or die(mysql_error());
while($row = mysql_fetch_array($result)){
set_qty($row['SUM(quantity)'], $row['finished_id']);
}
I know the sums are calculating correctly as I can echo them straight out, however I cannot get my table to update. Forgive me for the sloppy code I am very new with mysql entirely. Thank you in advance for the help.

Answer 1

I don't know why you use text type to store id. By the way
update summary_finished as sf
inner join (
select finished_id,
sum(quantity) as total
from detail_finished
group by finished_id )as t
set sf.qoh = t.total
where sf.finished_id = t.finished_id