Help with a double left join
От | Ari Nepon |
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Тема | Help with a double left join |
Дата | |
Msg-id | JMEEKPBGBOBMKNANAGILMEIBCCAA.anepon@verveinternet.com обсуждение исходный текст |
Ответы |
Re: Help with a double left join
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Список | pgsql-sql |
I am trying to do a left join FROM [a table with two columns that have foreign IDs] LEFT JOIN [two other tables, each has a unique ID]. I have the left join working where I join only two tables (not three): <!--current SQL--> SELECT track.ID, track.employee, track.client, track.task, track.description, track.hours_used, track.f_date, project.project_name FROM track LEFT JOIN project ON track.project=project.project_id WHERE track.client LIKE '%MMColParam%' <!--end--> the two tables are track and project. Track is the left of the left join. It holds the foreign keys. project (and later clients) are the columns with the keys. I need to also left join clients ON track.client=client.ID. Would someone tell me how the SQL statement should be that allows me to do the two left joins? Would it be: <!--wishful thinking SQL--> SELECT track.ID, track.employee, track.task, track.description, track.hours_used, track.f_date, project.project_name, clients.name FROM track LEFT JOIN project ON track.project=project.project_id AND LEFT JOIN client ON track.client=clients.ID WHERE track.client LIKE '%MMColParam%' <!--end--> '%MMColParam%' is just a variable used to hold a querystring variable in case anyone was wondering. Thanks, Ari (database is MS access. language is ASP. Whole thing will eventually be redone in PostgreSQL and PHP, just as soon as I learn them:) ~~~~~~~~~~~~~~~~~~~~~~~~~ Ari Nepon MRB Communications 4520 Wilde Street, Ste. 2 Philadelphia, PA 19127 p: 215.508.4920 f: 215.508.4590 http://www.mrbcomm.com ----------------------------------------------------------------------- Sign up for our email list and receive free information about topics of interest to nonprofit communications, marketing, and community building professionals. Free resources, articles, tips. Go to http://www.mrbcomm.com and use the Mailing List form. -----------------------------------------------------------------------
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