Question

Hopefully I can do the problem justice, because it was too difficult to summarise it in the title! (suggestions are welcome in the comments)

Right, so here’s my table:

Tasks   task_id        (number)   job_id         (number)   to_do_by_date  (date)   task_name      (varchar / text)   status         (number)   completed_date (date) 

for arguments sake let’s make the values of status:

1 = New 2 = InProgress 3 = Done 

and what I’m having trouble trying to do is create a query that pulls back all of the tasks:

• where any of the tasks for a job_id have a status <> Done
  • except where all tasks for a job_id are are done, but one or more tasks have a completed_date of today
• ordered by the to_be_done_by date, but grouping all of the job_id tasks together
  • so the job_id with the next `to_do_by_date’ task is shown first

some information about the data:

• a job_id can have an arbitrary number of tasks

Here’s an example of the output I’m trying to get:

task_id   job_id   to_do_by_date   task_name   status   completed_date    1        1        yesterday        -          3        yesterday    2        1        today            -          3        today    3        2        now              -          3        today    4        2        2 hours time     -          2        {null}    5        2        4 hours time     -          2        {null}    6        2        tomorrow         -          1        {null}    7        3        3 hours time     -          2        {null}    8        3        tomorrow         -          1        {null}    9        3        tomorrow         -          1        {null} 

I’m using Oracle 10g, so answers for Oracle or ANSI SQL, or a hint for how to approach this would be ideal, and I can create Views or wrap this in a Stored Procedure to offload logic from the application if your solution calls for it.

here’s a sql script that will create the example test data shown above:

create table tasks (task_id number, job_id number, to_do_by_date date, task_name varchar2(50), status number, completed_date date); insert into tasks values (0,0,sysdate -2,    'Job 0, Task 1 - dont return!', 3, sysdate -2); insert into tasks values (1,1,sysdate -1,    'Job 1, Task 1', 3, sysdate -1); insert into tasks values (2,1,sysdate -2/24, 'Job 1, Task 2', 3, sysdate -2/24); insert into tasks values (3,2,sysdate,       'Job 2, Task 1', 3, sysdate); insert into tasks values (4,2,sysdate +2/24, 'Job 2, Task 2', 2, null); insert into tasks values (5,2,sysdate +4/24, 'Job 2, Task 3', 2, null); insert into tasks values (6,2,sysdate +1,    'Job 2, Task 4', 1, null); insert into tasks values (7,3,sysdate +3/24, 'Job 3, Task 1', 2, null); insert into tasks values (8,3,sysdate +1,    'Job 3, Task 2', 1, null); insert into tasks values (9,3,sysdate +1,    'Job 3, Task 3', 1, null); commit; 

Many, many thanks for your help :o)

Answer 1

Obviously you will have to fix this up a bit but I hope you get the idea.

SELECT      task_id, job_id, to_do_by_date, task_name, status, completed_date FROM     Tasks WHERE     job_id IN (         SELECT job_id          FROM Tasks          WHERE status <> 'Done'          GROUP BY job_id)     OR     job_id IN (         SELECT job_id          FROM Tasks          WHERE status = 'Done' AND completed_date = 'Today'             AND job_id NOT IN (SELECT job_id FROM Tasks WHERE status <> 'Done' GROUP BY job_id)         GROUP BY job_id) ORDER BY     job_id, to_do_by_date