Re: [OT] SQL-question

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.--- .- -- . ... wrote:
| There's something I must be missing in your question because as its
| stated it seems pretty straight forward....
|
| select of as partner_id from relationships where is = ?
|
Thats one part, but what if I am asking for the partner of someone who
itself is registred as the 'of'-person. If the recor in Relationships is

1 is partner of 2

and then i need to find the partner of 2, I would need:
SELECT is AS partner_id FROM Relationships WHERE of = ?

My problem is how to write both querys as one.


| <Andreas.Fromm@xxxxxx.xxxxxxxxxxxx.xx> wrote:
|
| Hi,
|
| i know I'm slightly off topic, but I don't know where else to ask. I
| have a little SQL-question abaut a linking table. I have the following
| tables:
|
| CREATE TABLE Person (
| ~  id serial PRIMARY KEY
| ~  name text,
| ~  ...
| );
|
| CREATE TABLE Relations (
| ~  is integer REFERENCES Person,
| ~  rel char(7) CHECK ( rel == 'partner' OR ... ),
| ~  of integer REFERENCES Person,
| ~  CONSTRAINT Relations_pkey PRIMARY KEY ( is, rel )
| );
|
| Now I would like to make a query to the Relations table asking if some
| 'person' is the partner of another, and get the id of the partner. How
| would the SQL look like if I just have the row (1 is partner of 2) and
| not the row (2 is partner of 1) in the Relations table?
|
| Thanks in advance.
|

- --
Grüsse,

Andreas Fromm

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