List:General Discussion« Previous MessageNext Message »
From:Paul DuBois Date:May 10 2002 10:17pm
Subject:Re: quick sql question
View as plain text  
At 18:13 -0400 5/10/02, Augey Mikus wrote:
>so i suppose an automatic delete of every duplicate record is out of 
>the question :-)

Sounds like you're trying to have it both ways.

>
>Paul DuBois wrote:
>
>>At 18:00 -0400 5/10/02, Augey Mikus wrote:
>>
>>>is there a way for me to do it in a mysql delete statement?  just 
>>>out of curiosity, for instance, if i wanted to add duplicates 
>>>later for whatever reason.
>>
>>
>>Okay, let's suppose you have 3947 instances of "abc".
>>You can use LIMIT for this:
>>
>>DELETE FROM tbl_name WHERE col_name = "abc" LIMIT 3946;
>>
>>>
>>>Paul DuBois wrote:
>>>
>>>>At 17:54 -0400 5/10/02, Augey Mikus wrote:
>>>>
>>>>>what i meant is deleting duplicate occurences of records of a 
>>>>>certain field. ...sorry...
>>>>
>>>>
>>>>
>>>>Ah.
>>>>
>>>>One thing you can do is add a unique index on that field with
>>>>ALTER IGNORE TABLE tbl_name ADD UNIQUE (col_name)
>>>>or
>>>>ALTER IGNORE TABLE tbl_name ADD PRIMARY KEY (col_name)
>>>>
>>>>and MySQL will clobber duplicate records as it builds the index.
>>>>
>>>>>
>>>>>
>>>>>Paul DuBois wrote:
>>>>>
>>>>>>At 17:16 -0400 5/10/02, Augey Mikus wrote:
>>>>>>
>>>>>>>what is the simplest way to delete duplicate occurences of a 
>>>>>>>specific field in mysql?
>>>>>>>
>>>>>>>thanks,
>>>>>>>
>>>>>>>augey
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>Your question is a bit ambiguous.  You could do this by using
> ALTER
>>>>>>TABLE to remove the column itself from the table, for example,
> but
>>>>>>I'm guessing maybe that's not what you mean.

Thread
quick sql questionAugey Mikus10 May
  • Re: quick sql questionPaul DuBois10 May
  • Re: quick sql questionAugey Mikus10 May
    • Re: quick sql questionPaul DuBois10 May
  • Re: quick sql questionAugey Mikus10 May
    • Re: quick sql questionPaul DuBois10 May
  • Re: quick sql questionAugey Mikus11 May
  • Re: quick sql questionAugey Mikus11 May
    • Re: quick sql questionPaul DuBois11 May
      • Repair with key cachesup-mysql11 May
        • Re: Repair with key cacheBenjamin Pflugmann11 May
          • Re: Repair with key cachesup-mysql11 May
            • Re: Repair with key cachePaul DuBois12 May
              • Re: Repair with key cachesup-mysql12 May
              • Re: Repair with key cachesup-mysql12 May
                • Re: Repair with key cachePaul DuBois12 May
                  • Re: Repair with key cachesup-mysql12 May
                    • Re: Repair with key cacheJeremy Zawodny12 May
                      • RE: Repair with key cacheRamon Arias13 May
                        • Re: Repair with key cacheJeremy Zawodny13 May
  • Re: quick sql questionAugey Mikus11 May