RE: Deleting Duplicated Records
You are 100% correct. Since MySQL does not support cursors, I always put an auto_increment column in my tables for just this purpose. (This is what other DBMS' do, they just do it behind your back) Unfortunately, the way MySQL really handles result sets doesn't lend itself to simply adding a hidden auto_increment field to each row to act as a cursor and allow updating of rows in result sets. If it did, then I'm sure they would have put cursor support in the product already. Ken -Original Message- From: Jeffrey Flowers [mailto:[EMAIL PROTECTED]] Sent: Wednesday, April 10, 2002 11:16 AM To: [EMAIL PROTECTED] Subject: Deleting Duplicated Records I am new to MySQL and I have a test database that I am playing with. Through an accident while playing around, I ended up with two identicle records in the database. I did a filter to try and change just one of them but both would come up, so I couldn't see how I was supposed to delete just one of the two records. In the end, I deleted both records and re-input the one I needed but I know that there must be a better way of doing this. Perhaps having a column in my database with a serialized, unique record number would be a way to prevent this in the future? Thanks, Jeff Flowers - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: Deleting Duplicated Records
You are 100% correct. Since MySQL does not support cursors, I always put an auto_increment column in my tables for just this purpose. (This is what other DBMS' do, they just do it behind your back) You're right. I use DBase IV at work and every record has an internal record number. Unfortunately, the way MySQL really handles result sets doesn't lend itself to simply adding a hidden auto_increment field to each row to act as a cursor and allow updating of rows in result sets. If it did, then I'm sure they would have put cursor support in the product already. Ken Thanks for the help. - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
Re: Deleting Duplicated Records
On 10 Apr 2002, at 12:16, Jeffrey Flowers wrote: Perhaps having a column in my database with a serialized, unique record number would be a way to prevent this in the future? That would allow you to delete just one of the duplicates (which you also do with LIMIT 1 on your DELETE query), but it might be better to avoid inserting the duplicates in the first place. You could define a unique index on whatever combination of columns must be unique for a record (which in most tables is not going to be all the columns). -- Keith C. Ivey [EMAIL PROTECTED] Tobacco Documents Online http://tobaccodocuments.org - Before posting, please check: http://www.mysql.com/manual.php (the manual) http://lists.mysql.com/ (the list archive) To request this thread, e-mail [EMAIL PROTECTED] To unsubscribe, e-mail [EMAIL PROTECTED] Trouble unsubscribing? Try: http://lists.mysql.com/php/unsubscribe.php
