Solved

Sum up Childs

Posted on 2013-01-28
4
152 Views
Last Modified: 2013-09-15
Im looking for advise on working summing together all the time spent on a particular job, however also including child jobs.

So currently I have a table with 3 coloums:-
JobNo (smallInt)
ParentJobNo (smallInt)
TimeSpend (smallInt)

Filled with some test data:-

JobNo      ParentJobNo      TimeSpent
10                  5
11      10            10
12      10            15
13      10            5
14      10            10
15      14            15
16      14            20
17      13            5
18                  10
19                  15
20      19            10

Currently we have the query:-
SELECT Jobs.JobNo, Jobs.TimeSpent
FROM Jobs
WHERE (((Jobs.ParentJobNo) Is Null));

Open in new window


Which gives:-
JobNo            TimeSpent
10            5
18            10
19            15

However what I would like it to do is sum all the child jobs, and child jobs in that, so the correct answer would be:-
JobNo      TimeSpent
10      85
18      10
19      25


My current idea is to create a function in PHP to look at each row, and look for child jobs and then children of that returning the number each time, but I would prefer to do this in the query itself.

I did think of creating a function in MySQL, but as the function would have to have use recursion, which is set to quite low on my shared server.

Im going to be using MySQL in the end, but using Access to quickly show my issue.

I hope someone can cope up with a better idea.
0
Comment
Question by:tonelm54
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
4 Comments
 
LVL 40

Expert Comment

by:als315
ID: 38827551
0
 
LVL 25

Expert Comment

by:Tomas Helgi Johannsson
ID: 38834890
Hi!

Try this

SELECT x.JobNo,SUM(x.TimeSpent) from(
SELECT b.ParentJobNo as JobNo, a.TimeSpent
FROM Jobs a, Jobs b
where a.JobNo = b.ParentJobNo
UNION ALL
SELECT c.ParentJobNo as JobNo, c.TimeSpent
FROM Jobs c
WHERE c.ParentJobNo Is Null))
)X
GROUP BY x.JobNo

Regards,
     Tomas Helgi
0
 

Author Comment

by:tonelm54
ID: 38884529
When I try I run the query:-
SELECT x.JobNo,SUM(x.TimeSpent) from(
SELECT b.ParentJobNo as JobNo, a.TimeSpent
FROM Jobs a, Jobs b
where a.JobNo = b.ParentJobNo
UNION ALL
SELECT c.ParentJobNo as JobNo, c.TimeSpent
FROM Jobs c
WHERE c.ParentJobNo Is Null))
)X
GROUP BY x.JobNo

Open in new window


MySQL says:-
Error Code: 1248. Every derived table must have its own alias      

If I do a quick dump on the database table, Ive got:-
CREATE TABLE `jobs` (
  `JobNo` int(11) NOT NULL,
  `ParentJobNo` int(11) DEFAULT NULL,
  `TimeSpent` int(11) DEFAULT NULL,
  PRIMARY KEY (`JobNo`)
);

INSERT INTO `jobs` VALUES (10,NULL,5),(11,10,10),(12,10,15),(13,10,5),(14,10,10)
,(15,14,15),(16,14,20),(17,13,5),(18,NULL,10),(19,NULL,15),(20,19,10);

Open in new window


Can you advise, the query seems to do what I want, but I cannot understand it to figure out how to debug it.
0
 
LVL 43

Accepted Solution

by:
Rob earned 500 total points
ID: 39448527
You need to specify an alias for the table and remove the erroneous brackets

SELECT x.JobNo,SUM(x.TimeSpent) from(
SELECT b.ParentJobNo as JobNo, a.TimeSpent
FROM Jobs a, Jobs b
where a.JobNo = b.ParentJobNo
UNION ALL
SELECT c.ParentJobNo as JobNo, c.TimeSpent
FROM Jobs c
WHERE c.ParentJobNo Is Null
) as x
GROUP BY x.JobNo

Open in new window

0

Featured Post

Three Reasons Why Backup is Strategic

Backup is strategic to your business because your data is strategic to your business. Without backup, your business will fail. This white paper explains why it is vital for you to design and immediately execute a backup strategy to protect 100 percent of your data.

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

This article describes how to use the timestamp of existing data in a database to allow Tableau to calculate the prior work day instead of relying on case statements or if statements to calculate the days of the week.
Introduction This article is intended for those who are new to PHP error handling (https://www.experts-exchange.com/articles/11769/And-by-the-way-I-am-New-to-PHP.html).  It addresses one of the most common problems that plague beginning PHP develop…
Attackers love to prey on accounts that have privileges. Reducing privileged accounts and protecting privileged accounts therefore is paramount. Users, groups, and service accounts need to be protected to help protect the entire Active Directory …

737 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question