Need help on derivation of complex column

Question

Hi,
I have a requirement to derive a column in my report which has slightly complex logic and hence need your help.
I have oracle 10g database.
Background: The data is stored in a quiet complex way in table hence trying to let you understand in words. I have incidences stored in my table. These incidences can be completed by certain numbers of plans and further a single plan can be completed by certain numbers of activities. Structure is like below.
Table 1
*Incidences*            *Incidence_id*
Incidence_1                     1
Incidence_2                     2
Incidence_3                     3
Table 2
*Plan_name*        *Plan_id*     *incidence_id*
Plan_1                       1             1
Plan_2                       2             1
Plan_3                       3             1
Plan_1                       1             2
Plan_2                       2             2
Plan_3                       3             2
Plan_1                       1             3
Plan_2                       2             3
Plan_3                       3             3
I have Activity 1, Activity 2, Activity 3, Activity 4 are predefined activities which can be repeated in a plan like shown in below table.
Table 3
*Activity _name*      *Activity_id*        *Plan_id*           *incidence_id*
Activity_1                      1                      1                     1
Activity_2                      2                      1                     1
Activity_3                      3                      1                     1
Activity_4                      4                      1                     1
Activity_1                      5                      1                     1
Activity_1                      6                      2                     1
Activity_2                      7                      2                     1
Activity_3                     8                       3                     1
Activity_2                     9                       3                     1
Activity_1                    10                      3                     1Now in table 3 for plan_id 1 I have two Activity 1 and one Activity 3. from my functional knowledge I know that first Activity 1 is the parent activity of Activity 3, but there is no any way in a table to identify that logically. Can you please tell me any way so that I can have first Activity 1 as my output if I want parent activity of Activity 3?
Let me know if you have any questions to understand my requirement.
Edited by: 968625 on Jan 14, 2013 7:08 AM
Edited by: 968625 on Jan 14, 2013 7:37 AM

Answer 1

Hi,
968625 wrote:
Hi,
I have a requirement to derive a column in my report which has slightly complex logic and hence need your help.
I have oracle 10g database.
Background: The data is stored in a quiet complex way in table hence trying to let you understand in words. I have incidences stored in my table. These incidences can be completed by certain numbers of plans and further a single plan can be completed by certain numbers of activities. Structure is like below.
Table 1
*Incidences*            *Incidence_id*
Incidence_1                     1 ...
Whenever you have a question, please post CREATE TABLE and INSERT statements for your sample data, so the poeple who want to help you can re-create the problem and test their ideas. Also post the results you want from that data.
See the forum FAQ {message:id=9360002}
Now in table 3 for plan_id 1 I have two Activity 1 and one Activity 3. from my functional knowledge I know that first Activity 1 is the parent activity of Activity 3, but there is no any way in a table to identify that logically. Can you please tell me any way so that I can have first Activity 1 as my output if I want parent activity of Activity 3?If you want a query to know (or deduce) that Activity 1 is the parent of Activity 3, then that information has to be stored someplace where the query can see it.
If each activity can have (at most) 1 parent, then it seems like the most logical place is the table3: add another column to the table, and keep the parent activity there.
If a single parent can have multiple children, and, at the same time, a single child can have multiple parents, then you probably need a separate table for the parent-child relationships.
You could hard-code information about the parent-child relationships in the query itself, but I doubt that's the best way to solve this problem.
Let me know if you have any questions to understand my requirement.I don't understand what results you want from the given data. Once again, please post CREATE TABLE and INSERT statements for the sample data, and the exact results you want. Use specific examples from that output to explain how you get the right results from the given data.