VBA Data Type for SQL Server uniqueidentifier Type

[Don]

What is the proper (or preferred) VBA data type for MS SQL Server's
uniqueidentifier data type?

Thanks!

Don

 

[Van T. Dinh]

Check Access VB Help on the StringFromGUID() and GUIDFromString() function.

 

[TC]

If it does indeed map to a GUID - which I do not personally know one
way or the other - the OP should read the following article, before he
plans on using it: http://www.trigeminal.com/usenet/usenet011.asp

HTH,
TC [MVP Access]

 

[Don]

Thanks to both of you!! The string utilities will cover my needs and the
article on GUIDs and keys is pretty interesting.

Thanks again!

Don

 

[david epsom dot com dot au]

.... leading to this classic posting from the same author:

http://groups.google.com.au/group/m..._frm/thread/a4ea38af1c454280/fe9290a80eb2ef4c

(david)

 

[TC]

OT, but, why does he say that a double is subject to floating point
issues? A double is an exact representation, afaik. No fp issues
involved, at all ...

TC [MVP Access]

 

[John Nurick]

A double is a floating point type and as such can only provide exact
representations of an infinitesimal subset of real numbers. All the
usual FP issues apply.

See e.g. http://docs.sun.com/source/806-3568/ncg_goldberg.html and
http://www.cygnus-software.com/papers/comparingfloats/comparingfloats.htm

OT, but, why does he say that a double is subject to floating point
issues? A double is an exact representation, afaik. No fp issues
involved, at all ...

TC [MVP Access]

 

[david epsom dot com dot au]

Most notably, doubles that go through

SQL Server->ODBC->Access

may be different by the time they go back

Access->ODBC->SQL Server

which was the primary reason for using a 'time_stamp'
field on SQL Server tables used with Access.

Generally, doubles are a bad choice for primary key
because, unless you are familiar with the platform,
you can't tell if they will work at all. So any
general db advice has to advise against that.

(david)

 

[TC]

Holy cow! I always assumed they were "long long"s. I hope I haven't
used them anywhere! I certainly concur that a real/float data type
should never be used as a primary key. Thanks both, for the info.

Cheers,
TC [MVP Access]

 

[david epsom dot com dot au]

One of the DateTime types in SQL Server is LongLong.

It maps to an Access DateTime field, and is the
field type used by the Access upsizing wizard for
Access DateTime fields.

So you always get floating point conversion on
DateTime fields when you connect Access to SQL
Server.

(david)