Mike--
I hate to suggest quick fixes :) but if all else fails, you can add a
DISTINCT to the query. I've had to do it before...
If you keep running into problems, and EXPLAIN ... doesn't resolve them,
then perhaps you could send us a dump of the db structure...
# mysqldump -d [database_name] > dumpfile.sql
Or if you need a UN/PW:
# mysqldump -d [database_name] -u[username] -p > dumpfile.sql
That will dump the structure of the db, but not the actual data.
Good luck!
-----Original Message-----
From: Mike Gifford [mailto:[EMAIL PROTECTED]]
Sent: Thursday, July 12, 2001 10:48 AM
To: Matthew Loff
Cc: 'Dobromir Velev'; [EMAIL PROTECTED]; [EMAIL PROTECTED]
Subject: Re: [PHP-DB] Left Join is producing duplicate results - MySQL &
relational tables
Hi Matthew,
Matthew Loff wrote:
> What about...
> SELECT WLPbib.bibID,
> WLPbib.title,
> WLPbib.publisher,
> WLPbib.publicationDate,
> WLPaddress.city,
> WLPaddress.state,
> WLPprofile.firstName,
> WLPprofile.lastName,
> WLPprofile.organization,
> WLPcountry.languageName
> FROM WLPprofile, WLPaddress, WLPcountry
> WHERE WLPprofile.profileID = WLPbib.profileID
> AND WLPaddress.publisherID = WLPbib.publisherID
> AND WLPcountry.countryID = WLPaddress.countryID;
I think that this is working now.
> I had a similar problems with a database I was working with... It had
> a main table with 29,000 listings, and I decided to normalize it to
> improve query times (split the records into diff. tables, one for each
> attribute of the record, associate the records back together by a
> common ID than spanned all the tables)...
This one will likely have 10,000 to start with, so it is good to build
in
normalization... Didn't even know what the term normalization referred
to
earlier today. However, that is what I was doing with the table.
> I ended up with an SQL query that
> spanned like 10 tables-- but it was -way- faster than one big table.
> There's an excellent article on Normalization on PHPbuilder --
> http://www.phpbuilder.com/columns/barry20000731.php3
This is a good article. Even addressed the question that I fired off to
Dobromir about linking various profiles to the same bibliography.
One person can write many articles & an article can have many authors,
so I need
to create a many-many table to link the articles to profiles.
I think that this wil work:
CREATE TABLE WLParticle2profile (
a2pID mediumint(9) NOT NULL auto_increment,
bibID mediumint(9),
profileID mediumint(9),
PRIMARY KEY (a2pID)
)
I'll then need to Re-jig the WHERE command to limit the number of
returns...
This would become
SELECT WLPbib.bibID,
WLPbib.title,
WLPbib.publisher,
WLPbib.publicationDate,
WLPaddress.city,
WLPaddress.state,
WLPprofile.firstName,
WLPprofile.lastName,
WLPprofile.organization,
WLPcountry.languageName
FROM WLPprofile, WLPaddress, WLPcountry, WLParticle2profile
WHERE WLParticle2profile.profileID = WLPbib.profileID
AND WLPaddress.publisherID = WLPbib.publisherID
AND WLPcountry.countryID = WLPaddress.countryID;
I'm not sure this will work to tie in the relational table
and then we come back to the problem with duplicate entries again...
> If your WLP tables are very large, you may want to try using mySQL's
> EXPLAIN SELECT [rest of select query]... function to figure out the
> best
> (read: efficient) ways of performing this query... Indexes are
> definitely a must if you are dealing with a lot of rows... If not, you
> should be just fine with the above query-- which I -think- is
> equivilent...
I didn't know about this option:
http://www.mysql.com/doc/E/X/EXPLAIN.html
I find the MySQL.com site to be hard to read through.. php.net is much
easier
to understand in my experience.
> I don't have a ton of experience with SQL, so perhaps someone can
> better elaborate.
I think that you did a good job.. However I think I'm still stuck with
the same
duplicate error now (well when I've expanded the code.
Mike
> -----Original Message-----
> From: Dobromir Velev [mailto:[EMAIL PROTECTED]]
> Sent: Thursday, July 12, 2001 3:01 AM
> To: [EMAIL PROTECTED]; Mike Gifford
> Subject: Re: [PHP-DB] Left Join is producing duplicate results - MySQL
&
> relational tables
>
>
> Hi,
>
> Did you try to use something like this.
>
> mysql_query("SELECT DISTINCT
> WLPbib.bibID,
> WLPbib.title,
> WLPbib.publisher,
> WLPbib.publicationDate,
> WLPaddress.city,
> WLPaddress.state,
> WLPprofile.firstName,
> WLPprofile.lastName,
> WLPprofile.organization,
> WLPcountry.languageName
> FROM ((WLPbib
> LEFT JOIN WLPprofile ON WLPprofile.profileID =
> WLPbib.profileID)
> LEFT JOIN WLPaddress ON WLPaddress.publisherID =
> WLPbib.publisherID)
> LEFT JOIN WLPcountry ON WLPcountry.countryID =
> WLPaddress.countryID");
>
> The other thing that may help is to rearange the order of the tables
> in the FROM clause. Please check if some of the joins return more than
> one result - if you have more than one address for a publisher the
> query will return one row for every address.
>
> Hope this helps
> Dobromir Velev
>
>
> -----Original Message-----
> From: Mike Gifford <[EMAIL PROTECTED]>
> To: [EMAIL PROTECTED] <[EMAIL PROTECTED]>
> Date: Thursday, July 12, 2001 4:31 AM
> Subject: [PHP-DB] Left Join is producing duplicate results - MySQL &
> relational tables
>
>
>
>>Hello,
>>
>>I posted this to the general list this morning & got a couple of good
>>
> leads, but
>
>>they weren't able to actually fix the problem, so I'm posting here to
>>the
>>
> db list.
>
>>I'm making some headway on joining three MySQL tables.
>>
>>However, when I run this query:
>>
>>mysql_query("SELECT
>> WLPbib.bibID,
>> WLPbib.title,
>> WLPbib.publisher,
>> WLPbib.publicationDate,
>> WLPaddress.city,
>> WLPaddress.state,
>> WLPprofile.firstName,
>> WLPprofile.lastName,
>> WLPprofile.organization,
>> WLPcountry.languageName
>> FROM WLPbib
>> LEFT JOIN WLPprofile ON WLPprofile.profileID =
>>
> WLPbib.profileID
>
>> LEFT JOIN WLPaddress ON WLPaddress.publisherID =
>>
> WLPbib.publisherID
>
>> LEFT JOIN WLPcountry ON WLPcountry.countryID =
>>
> WLPaddress.countryID");
>
>>I now get results in triplicate. ie. I'm getting three copies of the
>>same title, firstName, organization, etc....
>>
>>I somehow suspected that this should be the result with LEFT JOIN, but
>>I'm
>>
> not
>
>>sure how to return a query without duplication.
>>
>>This is far better than what I had this morning (which was no response
>>from
>>
> the
>
>>server).
>>
>>Thanks. I'm new to joining tables...
>>
>>Someone wrote back suggesting that SELECT DISTINCT could be used to to
>>the
>>
> job.
>
>>Another person suggested that using UNIQUE(profileID) would make it
>>look
>>
> nicer.
>
>> I wasn't sure how to use UNIQUE with the last JOIN as it isn't
>>directly
>>
> linked
>
>>to WLPbib..
>>
>>Any suggestions would be useful.
>>
>>Mike
>>
>>--
>>Mike Gifford, OpenConcept Consulting, http://openconcept.ca Offering
>>everything your organization needs for an effective web site. Abolish
>>Nuclear Weapons Now!: http://pgs.ca/petition/ It is a miracle that
>>curiosity survives formal education. - A Einstein
>>
>>
>>--
>>PHP Database Mailing List (http://www.php.net/)
>>To unsubscribe, e-mail: [EMAIL PROTECTED]
>>For additional commands, e-mail: [EMAIL PROTECTED]
>>To contact the list administrators, e-mail:
>>[EMAIL PROTECTED]
>>
>>
>>
>
>
--
Mike Gifford, OpenConcept Consulting, http://openconcept.ca Offering
everything your organization needs for an effective web site. Abolish
Nuclear Weapons Now!: http://pgs.ca/petition/ It is a miracle that
curiosity survives formal education. - A Einstein
--
PHP Database Mailing List (http://www.php.net/)
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
To contact the list administrators, e-mail: [EMAIL PROTECTED]
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