On Tue, Feb 20, 2001 at 06:56:28PM +0800, chchen wrote:
> hi all
>
> i use mysql-3.23.32
>
> my project need to use unsigned Bigint as a primary key.
> but when i insert many rows in this table.
> sometimes it will error with Duplicate such like
>
> insert into Table
>values('9231852172526977164',0,0,52056,0,0,0,0,0,52056,0,0,0,0,0,0,0,11,0,'184000','184000',1),'9231898557453533324',0,0,5532,0,0,0,0,0,5532,0,0,0,0,0,0,0,11,0,'184000','184000',1),'9230422383529723532',147,0,0,0,0,0,0,0,147,0,0,0,0,0,0,0,91,0,'184000','184000',1)
> query failed
> Duplicate entry '9231898557453533324' for key 1
>
> but actually if i select * from Table where a='9231898557453533324'
>
> it can't find anything.........what's wrong with this, bug?
>
> p.s. unsigned Bigint should be from 0 to 18446744073709551615, so
>'9231898557453533324' is included in it, right?
>
True, but the manual warns against using UNSIGNED BIGINT for anything
else than bitsets:
! BIGINT[(M)] [UNSIGNED] [ZEROFILL]
! A large integer. The signed range is -9223372036854775808 to
! 9223372036854775807. The unsigned range is 0 to
! 18446744073709551615. Note that all arithmetic is done using signed
! BIGINT or DOUBLE values, so you shouldn't use unsigned big integers
! larger than 9223372036854775807 (63 bits) except with bit functions!
! Note that `-', `+', and `*' will use BIGINT arithmetic when both
! arguments are INTEGER values! This means that if you multiply two
! big integers (or results from functions that return integers) you
! may get unexpected results if the result is larger than
! 9223372036854775807.
I could imagine that this includes using it for indexes, because
this will do some comparisons on BIGINT values. But then, the manual
is not conclusive about this I think.
Can you get away with smaller (i.e. UNSIGNED) BIGINT values? It may
be worth a try then.
Regards,
Fred.
--
Fred van Engen XO Communications B.V.
email: [EMAIL PROTECTED] Televisieweg 2
tel: +31 36 5462400 1322 AC Almere
fax: +31 36 5462424 The Netherlands
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