Can this be done using a single sql......

Question

Hi,
I have a problem to solve an was just wondering if it was possible to do it using a single sql. It is not imperative that I use a single sql but would like to know if it were possible and if so how, else I would appreciate if I was guided in the general direction where I may be able to find a solution....
1) Esstentially in this example an employee can have 3 types of managers 'A' 'B' or 'C'.
2) the emplyee must have 1 and only 1 manager of type 'A' (it is imperative that an emp have a manager of type A)
3) the employee can have multiple managers of Type B and C but it is possible that the emp does not have any manager of type B and C
We need a report which compares all the type B managers of an employee to the type A manager of the same employee and if any one of the Type B manager is same as the type A manager then the report indicates 'Equal' else the report indicates 'Not Equal'. if there is no type B manager for the employee then the report should show is as 'Not Equal'.
The same comparsion need to be done between type C and type A managers for the employee...
here are the scripts you would require to create a dummy table with data
?SCRIPTS START?
create table emp (empid number(3), mgrid number(3), mgr_type varchar2(1))
insert into emp values (1,3,'A')
insert into emp values (1,10,'B')
insert into emp values (1,14,'C')
insert into emp values (2,15,'A')
insert into emp values (3,10,'A')
insert into emp values (3,10,'B')
insert into emp values (3,10,'C')
insert into emp values (4,12,'A')
insert into emp values (5,2,'A')
insert into emp values (5,2,'B')
insert into emp values (5,3,'B')
insert into emp values (6,1,'A')
insert into emp values (6,5,'C')
select * from emp
?SCRIPTS-END?
EMPID> MGRID> M
1> 3> A
1 > 10 > B
1 > 14 > C
2 > 15 > A
3 > 10 > A
3 > 10 >B
3 > 10> C
4 >12 > A
4 > 12 > C
5 > 2 > A
5 >2 > B
5 > 3> B
6 > 1 > A
6 > 5 > C
6 > 7 > C
Expected Report
emp_id>     mgr_type_A>     mgr_type_B>     mgr_type_C
1>>>     3>>>          Not Equal>>>     Not Equal
2>>>     15>>>          Not Equal>>>     Not Equal
3>>>     10>>>          Equal>>>          Equal
4>>>     12>>>          Not Equal>>>     Equal
5>>>     2>>>          Equal>>>          Not Equal
6>>>     1>>>          Not Equal>>>     Not Equal
at the end of the day the report is to be exported as an xls. I would be using java to connect to the DB and create the xls. Obv I could run a simple sql and do a lot of comparision in java and get the desired report... What I am looking for is
- Is it possible using a single sql.
- if not.. is it better to use a pl/sql procedure or do it using java code.
the table has abt 100,000 records .... performance is not really a factor right now...
I just have no idea where to look.. I thought of pivot tables but could not find a solution... thought of decode as well... but again to no avail... (i am not oracle expert by any means....)
Appreciate any help I can get...
Thanks...
PS: Have used > to seperate the data.. since the preview of the post was truncating all spaces between the columns and was making it difficult to differetiate the data....
ooooppppsss....just realised i should have put this in the PL/SQL forum.. dont' seem to find an option to delete the post.. so if someone can move it to the other forum... it would be great....
Message was edited by:
user520267

Answer 1

Well, there are no moderators here, so you are going to have to get your answer here :-). Most of us that hang out in PL/SQL are here too.
Assuming that 4>>> 12>>> Not Equal>>> Equal is a typo because there is only one record for empid 4, this works. There may be more efficient ways but ...
SQL> SELECT a.empid, a.mgrid,
  2         NVL((SELECT 'EQUAL' FROM emp b
  3             WHERE b.empid = a.empid and
  4                   b.mgrid = a.mgrid and
  5                   b.mgr_type = 'B'), 'NOT EQUAL') bmgr,
  6         NVL((SELECT 'EQUAL' FROM emp c
  7             WHERE c.empid = a.empid and
  8                   c.mgrid = a.mgrid and
  9                   c.mgr_type = 'C'), 'NOT EQUAL') cmgr
10  FROM emp a
11  WHERE mgr_type = 'A';
     EMPID      MGRID BMGR      CMGR
         1          3 NOT EQUAL NOT EQUAL
         2         15 NOT EQUAL NOT EQUAL
         3         10 EQUAL     EQUAL
         4         12 NOT EQUAL NOT EQUAL
         5          2 EQUAL     NOT EQUAL
         6          1 NOT EQUAL NOT EQUALYou can format your code and data, as I did here, by using [ pre ] and [ /pre ] without the spaces around the text you want preserved. [ code ] and [ /code ] works too.
HTH
John