Re: [OT] SQL-question

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Andreas Fromm writes:
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 > .--- .- -- . ... wrote:
 > | There's something I must be missing in your question because as it=
s
 > | stated it seems pretty straight forward....
 > |
 > | select of as partner_id from relationships where is =3D ?
 > |
 > Thats one part, but what if I am asking for the partner of someone w=
ho
 > itself is registred as the 'of'-person. If the recor in Relationship=
s is
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 > 1 is partner of 2
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 > and then i need to find the partner of 2, I would need:
 > SELECT is AS partner_id FROM Relationships WHERE of =3D ?
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 > My problem is how to write both querys as one.

Try SQL's UNION, as in the following query to find the partner of 2:

SELECT of FROM relationships WHERE is =3D 2
UNION
SELECT is FROM relationships WHERE of =3D 2

Kings

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 > | <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 follo=
wing
 > | tables:
 > |
 > | CREATE TABLE Person (
 > | ~  id serial PRIMARY KEY
 > | ~  name text,
 > | ~  ...
 > | );
 > |
 > | CREATE TABLE Relations (
 > | ~  is integer REFERENCES Person,
 > | ~  rel char(7) CHECK ( rel =3D=3D '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.
 > |
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 > - --
 > Gr=FCsse,
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 > Andreas Fromm
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