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Great!
Now....I guess when the insert
fails, via iBatis and an SQL_Map, I will get an SQLExceptiion. Is there an easy
way to find the -803?
I want to intercept it and
re-throw only non 803 exceptions.
thanks,
Edwin
----- Original Message -----
Sent: Friday, September 15, 2006 12:08
PM
Subject: Re: finding unique keys
I just looked to see how Spring does it with DB2. They do look for
-803 as the error code from the SqlException. So I think your plan
sounds good.
Jeff Butler
On 9/15/06, Edwin
Lukaweski <[EMAIL PROTECTED]> wrote:
Thanks
for all the feed back!!!
Some answers:
1) I am
using DB2 for z/OS version 7
2) Yes, UUID's are by
definition 'universally unique', excpept whe two
are gengerated, say by
two different JVMs, within the same millisecond.
The, they
turn out to be duplicates.
3) I like the idea of doing
an optimistic INSERT. I have always had
trouble figuring which sql code
to look for that represents this situation.
As best I can tell, it is
SQLCODE 803. So, if I see this code in an
exception, loop again,
otherwise throw a real sqlexception.
What do you
think?
thanks,
Edwin
----- Original Message -----
From:
"Larry Meadors" <[EMAIL PROTECTED]>
To: <
[email protected]>
Sent: Friday, September 15, 2006
11:03 AM
Subject: Re: finding unique keys
> +1
;-)
>
> Larry
>
>
> On 9/15/06, Jeff Butler
< [EMAIL PROTECTED]>
wrote:
>>
>> Some thoughts...
>>
>> 1.
Aren't UUID's "universally unique" by definition? Are you sure
you
>> need
>> to do this?
>>
>> 2.
Table locking is almost always a bad idea. I had a similar
situation
>> to
>> yours in that past, and decided to take
the optomistic route, meaning...
>>
>> - generate the key
>> - insert the record
>> - if the insert blows because
of a duplicate key, then generate a new key
>> and try
again
>>
>> Since the likelihood of generating a duplicate
UUID should be very low,
>> this
>> approcah will work in
the vast majority of cases.
>>
>>
>> Jeff
Butler
>>
>>
>>
>>
>> On
9/15/06, Edwin Lukaweski <
[EMAIL PROTECTED]> wrote:
>> > Thanks for the
answer.
>> >
>> > I am stuck
with an existing table definition, in a schema, that I
>>
cannot
>> > modify at this point due to being in production.
>> >
>> > So, this is the
best method I can come up with.
>> >
>>
> also....now you have tweaked my curiosity. In
addition to the advice
>> > I
>> > am seeking, it I
could alter the table definition to use some form of
>> >
auto-increment, how would I retrieve the generated value in
iBatis?
>> >
>> > So.....I
now have two questions.
>> >
>> >
thanks,
>> > Ediwn
>> >
>> > -----
Original Message -----
>> > From: "Larry Meadors" < [EMAIL PROTECTED]>
>>
> To: <
[email protected]>
>> > Sent: Friday, September
15, 2006 10:14 AM
>> > Subject: Re: finding unique
keys
>> >
>> >
>> > > One question:
Why not just let the database do it and have it tell
>> > >
you
>> > > the generated key?
>> >
>
>> > > Larry
>> > >
>> >
>
>> > > On 9/15/06, Edwin Lukaweski < [EMAIL PROTECTED]>
wrote:
>> > >>
>> > >>
>> >
>> Hi:
>> > >>
>> >
>> I have a situation for which I need some
advice while using
>> > >> iBatis.
>> >
>>
>> > >> What I would like
to do is:
>> > >>
>> >
>> 1) generate a unique UUID style value in my
Java program
>> > >>
>> >
>> 2) lock a table, say tabxx
>> >
>>
>> > >> 3) SELECT on the
table to see if the UUID exists as a key
>> > >>
>> > >> 4) if so, add 1 to the
key and go to step 3
>> > >>
>> >
>> 5) if the key does NOT exist, insert the
record
>> > >>
>> >
>> 6) unlock the table
>> >
>>
>> > >> Can anyone get me
advice as to how to do this with iBatis?
>> >
>>
>> > >> Thanks, very musch, in
advance
>> > >>
>> > >>
Edwin
>> > >>
>> > >
>>
>
>> >
>>
>
>>
>>
>
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