"right" way to handle null date values?

[Dean Slindee]

I am looking for the "right" way to handle inserting and presenting null
date values.
Public Const c_NullDate As Date = #12:00:00 AM#
If I set the value of a date variable in an SQL Server insert statement to
c_NullDate, the insert statement works. When I re-read the row and display
the inserted date value in a text box, the string "1/1/1900" is displayed.
If one wanted the textbox to display an empty string, how should either the
insert to the db be handled, or should code to show a blank string in the
text box be added?

Thanks

Dean Slindee

[Kevin Yu [MSFT]]

RE: "right&quo t; way to handle null date values?

Hi Dean,

Generally, when you want to assign a null value to the data type, you can
use DBNull.Value. In database, the field will be marked as <null>. When you
bind the data source to a textbox, the textbox will display an empty string
if the value of the field is DBNull.Value.

If anything is unclear, please feel free to reply to the post.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

--------------------
| From: "Dean Slindee" <slindee@mindsp ring.com>
| Subject: "right" way to handle null date values?
| Date: Thu, 13 Nov 2003 22:15:17 -0600
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|
| I am looking for the "right" way to handle inserting and presenting null
| date values.
| Public Const c_NullDate As Date = #12:00:00 AM#
| If I set the value of a date variable in an SQL Server insert statement to
| c_NullDate, the insert statement works. When I re-read the row and
display
| the inserted date value in a text box, the string "1/1/1900" is displayed.
| If one wanted the textbox to display an empty string, how should either
the
| insert to the db be handled, or should code to show a blank string in the
| text box be added?
|
| Thanks
|
| Dean Slindee
|
|
|

[Dean Slindee]

Re: &quot;right&quo t; way to handle null date values?

Value of type 'System.DBNull' cannot be converted to 'Date'.

is returned by the VS.Net source editor. Still wishing for a way to insert
a null

value into a date field and subsequently into a date column in SQLServer.

Currently inserts '1/1/1900'

Thanks,

Dean Slindee

"Kevin Yu [MSFT]" <v-kevy@online.mic rosoft.com> wrote in message
news:S7UJTynqDH A.2396@cpmsftng xa06.phx.gbl...[color=blue]
> Hi Dean,
>
> Generally, when you want to assign a null value to the data type, you can
> use DBNull.Value. In database, the field will be marked as <null>. When[/color]
you[color=blue]
> bind the data source to a textbox, the textbox will display an empty[/color]
string[color=blue]
> if the value of the field is DBNull.Value.
>
> If anything is unclear, please feel free to reply to the post.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."
>
> --------------------
> | From: "Dean Slindee" <slindee@mindsp ring.com>
> | Subject: "right" way to handle null date values?
> | Date: Thu, 13 Nov 2003 22:15:17 -0600
> | Lines: 15
> | X-Priority: 3
> | X-MSMail-Priority: Normal
> | X-Newsreader: Microsoft Outlook Express 6.00.3790.0
> | X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.0
> | Message-ID: <#n8ipXmqDHA.28 08@TK2MSFTNGP10 .phx.gbl>
> | Newsgroups: microsoft.publi c.dotnet.langua ges.vb
> | NNTP-Posting-Host: 0-1pool36-160.nas14.milwa ukee1.wi.us.da. qwest.net
> 63.156.36.160
> | Path: cpmsftngxa06.ph x.gbl!TK2MSFTNG P08.phx.gbl!TK2 MSFTNGP10.phx.g bl
> | Xref: cpmsftngxa06.ph x.gbl microsoft.publi c.dotnet.langua ges.vb:156742
> | X-Tomcat-NG: microsoft.publi c.dotnet.langua ges.vb
> |
> | I am looking for the "right" way to handle inserting and presenting null
> | date values.
> | Public Const c_NullDate As Date = #12:00:00 AM#
> | If I set the value of a date variable in an SQL Server insert statement[/color]
to[color=blue]
> | c_NullDate, the insert statement works. When I re-read the row and
> display
> | the inserted date value in a text box, the string "1/1/1900" is[/color]
displayed.[color=blue]
> | If one wanted the textbox to display an empty string, how should either
> the
> | insert to the db be handled, or should code to show a blank string in[/color]
the[color=blue]
> | text box be added?
> |
> | Thanks
> |
> | Dean Slindee
> |
> |
> |
>[/color]

[Kevin Yu [MSFT]]

Re: &quot;right&quo t; way to handle null date values?

Hi Dean,

Please make sure to use DBNull.Value instead of DBNull. DBNull.Value cannot
be assigned to a DateTime object. However, it has to be assigned to the
value of a sqlParameter. Please try the following code.

SqlParameter p = new SqlParameter("@ ParaName", SqlDbType.DateT ime, 8);
p.Value = System.DBNull.V alue;

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

--------------------
| From: "Dean Slindee" <slindee@mindsp ring.com>
| References: <#n8ipXmqDHA.28 08@TK2MSFTNGP10 .phx.gbl>
<S7UJTynqDHA.23 96@cpmsftngxa06 .phx.gbl>
| Subject: Re: "right" way to handle null date values?
| Date: Fri, 14 Nov 2003 12:36:23 -0600
| Lines: 72
| X-Priority: 3
| X-MSMail-Priority: Normal
| X-Newsreader: Microsoft Outlook Express 6.00.3790.0
| X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.0
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| Newsgroups: microsoft.publi c.dotnet.langua ges.vb
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| X-Tomcat-NG: microsoft.publi c.dotnet.langua ges.vb
|
| Value of type 'System.DBNull' cannot be converted to 'Date'.
|
| is returned by the VS.Net source editor. Still wishing for a way to
insert
| a null
|
| value into a date field and subsequently into a date column in SQLServer.
|
| Currently inserts '1/1/1900'
|
| Thanks,
|
| Dean Slindee
|
| "Kevin Yu [MSFT]" <v-kevy@online.mic rosoft.com> wrote in message
| news:S7UJTynqDH A.2396@cpmsftng xa06.phx.gbl...
| > Hi Dean,
| >
| > Generally, when you want to assign a null value to the data type, you
can
| > use DBNull.Value. In database, the field will be marked as <null>. When
| you
| > bind the data source to a textbox, the textbox will display an empty
| string
| > if the value of the field is DBNull.Value.
| >
| > If anything is unclear, please feel free to reply to the post.
| >
| > Kevin Yu
| > =======
| > "This posting is provided "AS IS" with no warranties, and confers no
| > rights."
| >
| > --------------------
| > | From: "Dean Slindee" <slindee@mindsp ring.com>
| > | Subject: "right" way to handle null date values?
| > | Date: Thu, 13 Nov 2003 22:15:17 -0600
| > | Lines: 15
| > | X-Priority: 3
| > | X-MSMail-Priority: Normal
| > | X-Newsreader: Microsoft Outlook Express 6.00.3790.0
| > | X-MimeOLE: Produced By Microsoft MimeOLE V6.00.3790.0
| > | Message-ID: <#n8ipXmqDHA.28 08@TK2MSFTNGP10 .phx.gbl>
| > | Newsgroups: microsoft.publi c.dotnet.langua ges.vb
| > | NNTP-Posting-Host: 0-1pool36-160.nas14.milwa ukee1.wi.us.da. qwest.net
| > 63.156.36.160
| > | Path: cpmsftngxa06.ph x.gbl!TK2MSFTNG P08.phx.gbl!TK2 MSFTNGP10.phx.g bl
| > | Xref: cpmsftngxa06.ph x.gbl microsoft.publi c.dotnet.langua ges.vb:156742
| > | X-Tomcat-NG: microsoft.publi c.dotnet.langua ges.vb
| > |
| > | I am looking for the "right" way to handle inserting and presenting
null
| > | date values.
| > | Public Const c_NullDate As Date = #12:00:00 AM#
| > | If I set the value of a date variable in an SQL Server insert
statement
| to
| > | c_NullDate, the insert statement works. When I re-read the row and
| > display
| > | the inserted date value in a text box, the string "1/1/1900" is
| displayed.
| > | If one wanted the textbox to display an empty string, how should
either
| > the
| > | insert to the db be handled, or should code to show a blank string in
| the
| > | text box be added?
| > |
| > | Thanks
| > |
| > | Dean Slindee
| > |
| > |
| > |
| >
|
|
|

[Kevin Yu [MSFT]]

Re: &quot;right&quo t; way to handle null date values?

Hi Dean,

I'd like to know if this issue has been resolved yet. Is there anything
that I can help on this? I'm still monitoring on it.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."

[Jacky Ott]

Re: &quot;right&quo t; way to handle null date values?


Kevin,
Have you checked the field for DBNULL? Hope this will help you out.

http://msdn.microsoft.com/library/default.asp?url=/library/en-us/cpref/html/frlrfsystemdbnullclasstopic.asp

Kevin Yu [MSFT] wrote:[color=blue]
> Hi Dean,
>
> I'd like to know if this issue has been resolved yet. Is there anything
> that I can help on this? I'm still monitoring on it.
>
> Kevin Yu
> =======
> "This posting is provided "AS IS" with no warranties, and confers no
> rights."
>[/color]

[Kevin Yu [MSFT]]

Re: &quot;right&quo t; way to handle null date values?

Thank you, Jacky. I have checked that.

Kevin Yu
=======
"This posting is provided "AS IS" with no warranties, and confers no
rights."