|
|
hi
i want to know that how to handle the null values in the database. i had the text field that save the time of incident. in some cases the user does not input the time. i want to check that if time is null means user had given no input. how to make the check of that.
i had used recordset such as
if isnull(rsdata.field("time"))=true then
msgbox"novalue in the database"
else
msgbox"value in the databse is present.
but that does not work it gives error that specified field contain no data or item not listed in the database.
Tell me how to make the check that field is null in database.
ddd
|
|
|
|
|
That is exactly the way that you do it.
Well, the If statement uses a boolean expression, so if you have a boolean value, you don't need to compare it to anything:
If IsNull(rsdata.Field("time")) Then
Are you sure that the field is named "time"? Are you sure that you include that field when you fetch the data to the recordset?
---
b { font-weight: normal; }
|
|
|
|
|
I don't remember why I did it this way, I think there was a problem with IsNull not working wit DBNull in one of the projects I did.
Here was the workaround I came up with:
For Each Item As DataRow In Questions.Rows
If Item("question_fields").GetType.Name <> "DBNull" Then
...
End if
Next
Matthew Hazlett
Sometimes I miss the simpler DOS days of Borland Turbo Pascal (but not very often).
|
|
|
|
|
|
Assuming you can change the select statement, check for null values within the query. If necessary, change the value to a non-time value (such as the literal word 'NULL') and then have your code check for that constant.
|
|
|
|
|
Hello,
I am a VB6 programmer who has just downloaded VB.Net Express 2005.
I was wondering if there were any comboboxes with a multicolumn dropdown list built into VB.Net, or do we have to build our own custom control. If a custom control is necessary, can anyone recommend a book on building controls, or indeed a freeware control available on the internet.
I have programmed Access a lot and am used to the useful multicolumn comboboxes available there, and want to bring all that functionality to my VB.Net applications.
Many thanks,
Trimtrom
|
|
|
|
|
There isn't any built in support for it in the .NET Framework. But, there are lots of examples on how to build one. All you need to do is search the articles for Multicolumn Combobox[^].
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
|
|
|
|
|
|
An unhandeled execption has occured in your application.If you click continue the application will ignore this error and attempt to cont. if u click quit the appln will shut down immediately.
Object reference not set to an instance of an object....
and one more error...
SQL server access denied.
bhavna
|
|
|
|
|
Bhavna Varshney wrote: An unhandeled execption has occured in your application.If you click continue the application will ignore this error and attempt to cont. if u click quit the appln will shut down immediately.
Object reference not set to an instance of an object....
and one more error...
SQL server access denied.
And your question is...?
...Steve
"Give a man a fish and you've fed him for a day. Teach him how to fish and you've fed him for life." (Translation: I'll show you the way, but not write the code for you.) I read that somewhere once 
|
|
|
|
|
Congratulations on putting bugs into your code!
Now, what's your question?
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
|
|
|
|
|
whenever i run my application ....
n open the very first login page ....
error comes which is:
" An unhandled execption has occured in your application . if you click Continue,the application will ignore this error and attempt to continue.if you click Quit , the application will be shut down immediately.
Object reference not set to an instance of an object."
Hope you got the error.....
bhavna
|
|
|
|
|
I suspect that you do not have the correct version of the .NET framework on the client or that you are trying to run the app from an untrusted source (see the framework config control panel).
...Steve
"Give a man a fish and you've fed him for a day. Teach him how to fish and you've fed him for life." (Translation: I'll show you the way, but not write the code for you.) I read that somewhere once
|
|
|
|
|
|
You really need to run your in the debugger and test it cometely before you deploy a Release version somewhere. You'll need the debugger to find this error because you don't have enough information to diagnose this.
You're code, somewhere, is trying to use an object that doesn't have an instance. Many begginers make the mistake of calling a method with some parameters, and expect an object to be returned by the method, then they try to use the object that WASN'T returned by the method for some reason.
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
|
|
|
|
|
hello guys,
I am looking for a free component which enables me to use encryption using vb6 preferabley DES or RSA or alternatively any other one will go.
In case it is vb.net possibly would like to be able to call it from vb6/vbscript.
any example, resources around?
Any help will be appreciatd..
|
|
|
|
|
There are several encryption engines in the .NET Framework. DES, DSA, RC2, Rijndael, RSA, TripleDES, as far as I can see.
---
b { font-weight: normal; }
|
|
|
|
|
You could even make a library to do what you want and expose it to COM, callable by VBScript and VB6, using the methods outlines in Exposing .NET Framework Components to COM[^].
RageInTheMachine9532
"...a pungent, ghastly, stinky piece of cheese!" -- The Roaming Gnome
-- modified at 10:08 Friday 27th January, 2006
|
|
|
|
|
|
hi frndz,
i hav made my application in VB.Net and wish to implement on the client systems on the network.I wanna know that is it psbl to imoplement it on the clients with a centralized database and without any .Net framewokr installed on the clients.
thanx
reply ASAP
Bhavna
|
|
|
|
|
The short answer is No. If your application is to run on the client machines then you need the .NET Framework on the clients.
...Steve
"Give a man a fish and you've fed him for a day. Teach him how to fish and you've fed him for life." (Translation: I'll show you the way, but not write the code for you.) I read that somewhere once
|
|
|
|
|
I hav implemented with .net framework , but in that case i compromise on clinets speed.
cud u tell me what shud be the min LAN speed and h/w requirements of clients as well as server...
Reply ASAP.
Thanx
bhavna
|
|
|
|
|
Bhavna Varshney wrote: I hav implemented with .net framework , but in that case i compromise on clinets speed.
The loss of performance using .NET in real terms is relative to your expectations.
Bhavna Varshney wrote: cud u tell me what shud be the min LAN speed and h/w requirements of clients as well as server...
Mate, since I know nothing of your application, quantitative measures of its processing or database requirements, nor budget for this project, I can give you no real idea of this. If you need help on that, it sounds like a job for a professional consultant. I'd be glad to help but I'm in a different continent.
...Steve
"Give a man a fish and you've fed him for a day. Teach him how to fish and you've fed him for life." (Translation: I'll show you the way, but not write the code for you.) I read that somewhere once
|
|
|
|
|
if i let u know the configuration u may b able to find a solutn fir me....
I am having a server of 384 mb,a network of 6 clients but having low RAM ( does RAM affects ?),my application is of size 62 MB.
thanx
bhavna
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
