Subject: Struggling [Is : With database normalisation]

Probably something as simple as changing the structure to a more normalised form would help : By adding a table which links evt_details to evt_sponsors, you do away with the need to have (up to 4) distinct fields to hold the evt_sponsor in your evt_details table. So add something like table : evt_sponsors_list

evt_detail_link_id    INT 6

evt_sponsor_link_id INT 6 Then your query becomes more like : SELECT evt_detail_id, evt_detail_title, evt_sponsor_name FROM evt_details LEFT JOIN evt_sponsors_list ON evt_detail_id=evt_detail_link_id LEFT JOIN evt_sponsors ON evt_sponsor_link_id=evt_sponsor_id WHERE evt_detail_date <= DATE_SUB(NOW(), INTERVAL 1 DAY) The left join evt_sponsors_list will pull any number (1-many) of results where there is one or more matching sponsor. The left join evt_sponsors will then match those results to the evt_sponsors table, resulting in a series of rows for each event. You could change the 1st join to read 'LEFT OUTER JOIN' if you wanted to get events where there are *no* sponsors (what you were previously doing with OR e.evt_sponsor_id_n =0) This is a one-to-many relationship and allows you to have flexibility for any number of event sponsors (not just 4) without adding more and more fields to your event_detail table. Make sure to index both columns in the evt_detail_link table for good performance, and the storage overhead is almost neglible. You can then run a simple loop in PHP, cache the new row each time the evt_detail_id changes (containing the event title, the ID is useful so you can link to full details by event_id if you need to). Then for the 1st and subsequent rows, just use the evt_sponsor_name. Output the previous row when the evt_detail_id changes, and output the final row when there are no more results. Cheers - Neil. At 22:24 04/05/2004 +0000, you wrote:

PHP Database Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php From: "Erik Meyer" <emeyer@ebaseweb.com> To: "PHP-DB" <php-db@lists.php.net> Date: Tue, 4 May 2004 17:24:59 -0500 Message-ID: <DFEPKAKJMAFKINPMJGNNEEEGCCAA.emeyer@ebaseweb.com> MIME-Version: 1.0 Content-Type: text/plain;

        charset="iso-8859-1"

Content-Transfer-Encoding: 7bit Subject: Struggling Hope someone can help me. I have two tables: evt_details evt_sponsors The structure is as follows:

evt_details                                                     evt_sponsors

evt_detail_id           (INT)(PK)                       evt_sponsor_id (INT)(PK)
evt_detail_title                (CHAR)                  evt_sponsor_name (CHAR)
evt_sponsor_id1         (INT) NON-NULL
evt_detail_date         (date)
evt_sponsor_id2         (INT) NULL
evt_sponsor_id3         (INT) NULL
evt_sponsor_id4         (INT) NULL

Now, the event can have either 1 sponsor, 2 sponsors, 3 sponsors, or 4 sponsors. Is there a way where I can return a result whether it has 1, 2, 3, or 4 since some of the events will not have a 2d,3d, or 4th sponsor, a combination of 1 & 2, 1,2,3, or all 4 depending on the values in the table? Here is the query I have: SELECT e.evt_detail_title, a.evt_sponsor_name, b.evt_sponsor_name, c.evt_sponsor_name,

       d.evt_sponsor_name

FROM evt_sponsors a, evt_sponsors b, evt_sponsors c, evt_sponsors d, evt_details e WHERE e.evt_detail_date <= DATE_SUB(NOW(), INTERVAL 1 DAY) AND e.evt_sponsor_id1=a.evt_sponsor_id AND

      (e.evt_sponsor_id2=b.evt_sponsor_id OR e.evt_sponsor_id2=0) AND

(e.evt_sponsor_id3

       =c.evt_sponsor_id OR e.evt_sponsor_id3=0) AND

(e.evt_sponsor_id4=d.evt_sponsor_id OR e.evt_sponsor_id4 =0) Thanks for the help, Erik W. Meyer

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