To Identify Relationship between records in a table

Question

Hi
I need to write a query to identify what relationship exists between records in a table.
For example,In our system a manager can have more than 1 subordinate as well as an employee can also have more than 1 manager.
I need to provide the relationship for a given set of employee-ids whether it is
1 is to 1,
1 is to many,
many is to 1,
many to many.
Employee     Relationship     Relationship Description
John     1 is to M     Implies John is reporting to multiple managers who have only one subordinate
Stuart     1 is to 1     Implies Stuart is reporting to only one manager who has only one subordinate
Robert     M is to 1     Implies Robert is reporting to only one manager who has multiple subordinates
Martha     M is to M     Implies Martha is reporting to multiple managers who have multiple subordinates
Can you please help me with this query?
Regards
Kapil

Answer 1

To make things simple lets assume the following table structure and data
CREATE TABLE EMP
ENAME VARCHAR2(10),
MNAME VARCHAR2(10)
Data for M:1 Relationship
INSERT INTO EMP VALUES ('John','Linda');
INSERT INTO EMP VALUES ('Robert','Linda');
Data for 1:M Relationship
INSERT INTO EMP VALUES ('Peter','Stuart');
INSERT INTO EMP VALUES ('Peter','Linda');
Data for 1:1 Relationship
INSERT INTO EMP VALUES ('Mary','Tim');
Data for M:M Relationship
INSERT INTO EMP VALUES ('Chris','Roger');
INSERT INTO EMP VALUES ('Tom','Roger');
INSERT INTO EMP VALUES ('Stephen','Roger');
INSERT INTO EMP VALUES ('Stephen','Zoe');
Now if I search for Chris and Mary I should get the result as:-
Chris M:M
Mary 1:1
Hope this clarifies ;-)