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Re: Select, vielleicht UNION oder LEFT JOIN?
Posted by: Hartmut Holzgraefe
Date: March 02, 2009 03:07AM

Du musst die user Tabelle zweimal in die Abfrage
einbinden, einmal für den Schenker und einmal
für den Beschenkten. Das geht mit Table Aliases
in der Form "table_name AS alias_name" im FROM-
Teil:

SELECT user_from.name
, user_to.name
, geschenk.name
, user_to_geschenk.`timestamp`
FROM user_to_geschenk
, user AS user_from
, user AS user_to
, geschenk
WHERE user_to_geschenk.user_id_send = user_from.id
AND user_to_geschenk.user_id_become = user_to.id
AND user_to_geschenk.geschenk_id = geschenk.id
;

oder in JOIN-Schreibweise:

SELECT user_from.name
, user_to.name
, geschenk.name
, user_to_geschenk.`timestamp`
FROM user_to_geschenk
JOIN user AS user_from
ON user_to_geschenk.user_id_send = user_from.id
JOIN user AS user_to
ON user_to_geschenk.user_id_become = user_to.id
JOIN geschenk
ON user_to_geschenk.geschenk_id = geschenk.id
;

--
Hartmut Holzgraefe, MySQL Regional Support Manager EMEA

Sun Microsystems GmbH, Sonnenallee 1, 85551 Kirchheim-Heimstetten
Amtsgericht Muenchen: HRB161028
Geschaeftsfuehrer: Thomas Schroeder, Wolfgang Engels, Dr. Roland Boemer
Vorsitzender des Aufsichtsrates: Martin Haering

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Re: Select, vielleicht UNION oder LEFT JOIN?
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March 02, 2009 03:07AM


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