[AccessD] upsizing

Dan Waters dwaters at usinternet.com
Fri Aug 1 13:16:24 CDT 2008


Hi Charlotte,

I entered data directly into a SQL Server 2005 table bit field.  I was just
testing to see what information it would even take.  The only data that
field would take was a -1 or a 0.  I turned off Allow Nulls.

Then, using a recordset in Access 2003, I was able to read the -1 as True
and the 0 as False.

Given that, your code will work.  But you might be able to test for True and
False instead, IF you disallow nulls for the bit fields that are expected to
be either True or False.

Dan

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte Foust
Sent: Friday, August 01, 2008 10:32 AM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] upsizing

No, we use bits.  Nobody enters data directly into a table, so I'm not
sure what you're doing or which database you're talking about.  If
you're working with 2007, we aren't even in the same conversation.  We
stayed with 2002 and use a 2000 data format.  We interact with either BE
using SQL and/or dataadapters.  ADO has problems with evaluating True
and False if those values are embedded in the SQL, so we have to use
numbers for that or else use OleDbParameters to pass in True and allow
ADO to figure out which value to use.  Here's a sample of what I mean.
We're building the SQL string in code an then executing it.  Notice the
"CostCodes.CarryForward <> 0" bit.  CarryForward is a bit field.
ExecuteNonQuery is a wrapper for
System.Data.OleDb.OleDbCommand.ExecuteNonQuery.

    Public Sub CarryForwardDailyCosts(ByVal jobID As String, ByVal
reportNo As Short) _
					Implements
IDailyReportData.CarryForwardDailyCosts
        Dim strSQL As New Text.StringBuilder
        strSQL.Append("INSERT INTO DailyCosts (JobID, ReportNo, IDNo,
AccountCode, DailyCost, AFENo, Vendor, TransferFlag, Notes)")
        strSQL.AppendFormat(" SELECT DailyCosts.JobID, {0} As ReportNo,
DailyCosts.IDNo, DailyCosts.AccountCode, 	DailyCosts.DailyCost," ,
reportNo)
        strSQL.Append(" DailyCosts.AFENo, DailyCosts.Vendor, 1 as
TransferFlag,")
        'strSQL.Append(strNote)
        strSQL.Append(" DailyCosts.Notes")
        strSQL.Append(" FROM DailyCosts INNER JOIN CostCodes ON
DailyCosts.AccountCode = CostCodes.AccountCode")
        strSQL.AppendFormat(" WHERE DailyCosts.JobID = '{0}' AND
DailyCosts.ReportNo = {1} AND CostCodes.CarryForward <> 0", _
            jobID, reportNo - 1S)
        OleDbHelper.ExecuteNonQuery(New OleDbCommand(strSQL.ToString))
    End Sub

Charlotte Foust 

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters
Sent: Friday, August 01, 2008 5:25 AM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] upsizing

Well,

That wasn't what I saw with my testing.  In fact, with a bit field, I
couldn't even enter a 1 directly in the table.

Are you talking about using a smallint field for True or False?

Dan

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Charlotte
Foust
Sent: Thursday, July 31, 2008 7:51 PM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] upsizing

In Access, that's true.  In SQL Server, 1 is true and 0 is false.  If
you throw a -1 at it, it spits up all over you.

Charlotte Foust 

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Dan Waters
Sent: Thursday, July 31, 2008 3:03 PM
To: 'Access Developers discussion and problem solving'
Subject: Re: [AccessD] upsizing

With the BE I just upsized, all the Yes/No fields became bits.  I went
through all those fields and set Allow Nulls to False.

Now the only to values that can be entered into the bit fields are -1
and 0.

I set up a recordset to change iteratively change the value from True to
False then True then False, etc, and everything worked just as if I had
been using an Access table.

I went back and tested one field by setting Allow Nulls to True.  My
code then displayed the value as False if I set the field to Null in
code.

Dan

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Gustav Brock
Sent: Thursday, July 31, 2008 4:37 PM
To: accessd at databaseadvisors.com
Subject: Re: [AccessD] upsizing

Hi Charlotte

One way to get around this - if you really need to handle the value as a
numeric - is to use Abs():

  If Abs([YourYesNoField]) = 1 Then
    ' something
  End If

Another is to use DataTableAdapters and/or DAL to isolate you from this
low-level stuff. I couldn't imagine anything else than this is what you
do, but your reply indicates not. Is that really so?

/gustav

>>> cfoust at infostatsystems.com 31-07-2008 17:25 >>>
We have to be careful in our .Net code to always test for 0 or <> 0
because we run against both Access and SQL Server.  Trying to test for
True crashes on one or the other.

Charlotte Foust 

-----Original Message-----
From: accessd-bounces at databaseadvisors.com
[mailto:accessd-bounces at databaseadvisors.com] On Behalf Of Susan Harkins
Sent: Wednesday, July 30, 2008 4:48 PM
To: Access Developers discussion and problem solving
Subject: Re: [AccessD] upsizing

oooooooooooooo.... I like that. :)

Susan H.


> Possiby because Access uses -1  for True and you can't represent that 
> with a bit?
>
> What value does SSMA store insert a True record (1 or -1)?
>
>
> On 30 Jul 2008 at 18:45, Susan Harkins wrote:
>
>> SSMA converts Access Yes/No fields to tinyint, instead of bit -- does

>> anyone have an explanation for that?
>>
>> My guess is it's because SQL Server's bit didn't support NULL's until

>> 7.0, but it seems like the wizard would keep up with something like 
>> that. I really can't recall if Access' Yes/No always supported NULLs 
>> or not.
>>
>> Susan H.



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