He's just not doing a select max, which of course is a disaster. The method Christian
described is imho best: easy on resources and safe. What the author was talking about
looks workable but requires a lot of overhead (see below). Just brought it up as an
item of interest.
<cfloop condition="true">
<cftry>
<cftransaction>
<cf_max_ID
datasource="#application.mainDSN#"
tablename="users"
primarykey="userid">
<cfquery
name="addhistory"
datasource="#application.mainDSN#">
insert into users
(userid,firstname,lastname,email)
values
(#max_ID#,
'#trim(attributes.firstname)#',
'#trim(attributes.lastname)#',
'#attributes.email#')
</cfquery>
</cftransaction>
<cfbreak>
<cfcatch type="database">
</cfcatch>
</cftry>
</cfloop>
<!---
cf_max_id
required attributes
--->
<cfparam name="attributes.datasource">
<cfparam name="attributes.tablename">
<cfparam name="attributes.primarykey">
<cfquery
name="getmaxID"
datasource="#attributes.datasource#">
select max(#attributes.PrimaryKEY#) as Max_ID
from #attributes.tablename#
</cfquery>
<cfif len(getmaxID.Max_ID)>
<cfset caller.Max_ID = getmaxID.Max_ID + 1>
<cfelse>
<cfset caller.Max_ID = "1">
</cfif>
---------- Original Message ----------------------------------
From: [EMAIL PROTECTED]
Reply-To: [EMAIL PROTECTED]
date: Mon, 17 Mar 2003 15:20:39 -0700
>Using the maxid trick has problems though. In some databases, it will create a race
>condition. The only way to alleviate it is to set the transaction isolation level to
>"serializable".
>
>----- Original Message -----
>From: Matt Robertson <[EMAIL PROTECTED]>
>Date: Monday, March 17, 2003 2:53 pm
>Subject: Re: Using createUUID()
>
>> Chris,
>>
>> I've used the method you describe for awhile and prefer it. Your
>> post reminded me of another method that seems safe, but I never
>> went there. CF_MaxID:
>>
>> http://tinyclick.com/?T02MT2
>>
>> You need a transaction block inside of a try/catch block inside of
>> a loop to make it bombproof (:O) per the included docs, but it'll
>> apparently work without adding a second indexed field to your table.
>>
>> -------------------------------------------
>> Matt Robertson, [EMAIL PROTECTED]
>> MSB Designs, Inc. http://mysecretbase.com
>> -------------------------------------------
>>
>>
>> ---------- Original Message ----------------------------------
>> From: Christian Cantrell <[EMAIL PROTECTED]>
>> Reply-To: [EMAIL PROTECTED]
>> date: Mon, 17 Mar 2003 15:22:12 -0500
>>
>> >I posted some information on the createUUID function on my weblog
>> today
>> >based on an application I was working on over the weekend:
>> >
>> >http://www.markme.com/cantrell/weblog/index.cfm?m=3&d=17&y=2003
>> >
>> >Christian
>> >
>> >On Monday, March 17, 2003, at 07:55 AM, FlashGuy wrote:
>> >
>> >> Hi,
>> >>
>> >> I need to generate a unique ID for every form I submit. The
>> createUUID
>> >> # generated is just too long for my needs. My ID only needs to
>> be 10
>> >> characters in length. Something like:
>> >>
>> >> CT-0001001
>> >>
>> >> I'm using MySQL. Can I have mysql generate the unique ID? How
>> could I
>> >> do this with CF?
>> >
>> >
>>
>
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