Clarification About Which Datatype To Use
Feb 2, 2011
I'm using SQL Server 2008 and Visual Studio 2008 with .NET Framework 3.5. I'm teaching myself and this my first time posting a question here. And I was wondering if someone could clarify something for me.I've created a table called Classes. One of the columns is called Enrolled and is of data type tinyint (0 to 255) since the class will never have more than 50 students enrolled.In my application I created an object called ClassInfo and declared a private variable ..private _classAmt as byteMy question is this..What if someone wants a total of students enrolled for that year? Do I need to convert to a larger data type such as int32 or would it be better to set the data type as Integer in t
View 1 Replies
ADVERTISEMENT
Mar 8, 2010
anything wrong with using datatype object and determine datatype in class property? I have a typed dataset and it has several integers columns that are null in the db. and when I make a call it throws exception.is there anythign wrong with setting it as object in my dataset.. changing the throw exception property to Nothing and passing it to my property as integer?
for each row in myDS.DataTable
cRate.CustID = row.CustID
next row
and in my class
Public Property CustID() As Integer
Get
Return _custID[code].............
View 3 Replies
Apr 30, 2002
I'm using a 3rd party chart COM object (National Instruments CW graph) to plot data versus elapsed time.The x value needs to be a VB6 equivalent Date type which is a .NET DateTime datatype.What I need is a way to convert a TimeSpan datatype to a DateTime datatype.
Dim testTime as System.DateTime 'date
Dim plotTime as System.DateTime 'date
Dim elapsedTime as System.TimeSpan[code].....
View 2 Replies
Jan 15, 2012
I have a database in mysql. The column in table is of datatype time(0)
Similarly I have a control datetimepicker in vb.net I have assigned format property as custom to the control and the CustomFormat property as HH:mm:ss tt so that it can just provide the time. I dont want the date to be in it.
Issue comes when I try to retrieve the value from database I get an error as Converion of type 'Timespan' to type 'Date' is not valid
Try
Dim myCommand As SqlCommand
myCommand = New SqlCommand("select * from [HMS].[dbo].[DoctorSchedule] where DoctorID='" & txtDoctorID.Text & "'", Connection)
[Code].....
View 5 Replies
Jan 2, 2011
I am working on a produce inventory database in my VB Express program.I have a form on the bottom and a spreadsheet at the top. I want to enter all the data in the form and have that data automatically transferred as a group to the spreadshet in the upper part of the page when I press a button.I know that there's an insert function.I set it up correctly. The problem is that I have to convert the textbox, which contain string data, to the datatype used in the database spreadsheet.HOw do I use CAST or do this?Here's the function I am using:
Me.TableAdapterManager.InventoryTableAdapter.Insert(IDTextBox.Text, fruitName, unitprice, unitsize, unitIn, unitTransit, unitOut)
Evernything is a string cause the data is coming from a textbox, I need to convert it to the datatypes used in the database.Also how do I use the CAST and Convert functions
View 1 Replies
Mar 16, 2012
When this grabs the current process, the "current" process is the one that called this function, right? I.E., the process that is requesting this information is the current process, correct? For example, if the process that is running this piece of code right now has a pid of 1, the Process object returned by this function will tell me it has a pid of 1, correct? I cannot possibly get any other process, correct?
View 1 Replies
Jan 21, 2009
I am inclined to delve into it in the near future just to get a taste of it. I am looking into converting my single form Chat program to its WPF equivalent. The form that I am currently using have a RichTextbox control in it, I am not sure how WPF works but do I need to design a Richtextbox control using XAML/XML or just the specification on where it should be located?
View 2 Replies
Dec 8, 2010
I've read a lot on this, but am having a hard time thinking through this tonight. (Maybe it's the hydrocodone... just had a root canal. i'm just starting on a class to handle client connections to a TCP server. Here is the code I've written thus far:
[Code]...
Now, on my Socket property, when setting the value, it is required to be ByVal. It is my understanding that the instance in memory is copied, and this new instance is passed to value, and my code sets _Socket to reference this instance in memory. Yes?
If this is true, then I can't see why I would want to use properties for anything but native types. I'd imagine there can be quite a performance hit if copying class instances with lots of members. Also, for this code in particular, I'd imagine a copied socket instance wouldn't really work, but I haven't tested it yet.
View 3 Replies
Feb 11, 2010
When you declare an object 'WithEvents' and then utilize the "Handles" clause at the end of your event methods, how does Visual Basic manage a reference change for the object? In other words, if the withevents var is set to ObjectA, then later I switch it to ObjectB (or nothing), does Visual Basic automatically both remove those handler methods from ObjectA, and attach them to ObjectB? Or do I still have a ObjectA's events being handled behind the scenes?
I ask this because if instead you use AddHandler for an object, and then switch your reference, unless you removed the handler before switching, your original object is still handled (at least I'm pretty sure that's how it works).
View 13 Replies
Nov 1, 2010
I have a button that when clicked, creates an instance of a new form and assigns a value to .tag. I have the following code:
Private Sub btnNew_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnNew.Click
If Me.Tag = "NBI" Then
Dim NBIForm As New frmNewNBI
[code]....
View 5 Replies
Sep 9, 2009
I would need some clarification on a syntax : could someone tell me why some people in their code use the following :
If Not (xxx And yyy) = 0 Then
'code
End if
instead of
If xxx = true Then
'code
End if
As an exemple : In a code I use for a listview Item Ownerdraw, it sure works like this :
If Not (e.State And ListViewItemStates.Selected) = 0 Then
' draw the listview item code
End If
but not like this :
If e.State = ListViewItemStates.Selected Then
'
End If
View 3 Replies
Aug 6, 2010
If I have a class with a couple of event handlers inside of it which are attached to an object that is defined within the class, am I right in thinking that I don't need to implement IDisposable to remove said handlers, even if I explicitly added the handlers myself? Also, can anyone point me in the direction of an article that explains the scope of when it is needed to remove handlers to avoid memory leaks. (I've tried searching many times but I must be screwing up my search terms.)I have a collection; every time an object is added to that collection, I add a handler to a change event of the object.When I'm done with the collection, do I need to go through each item and remove the handler before setting the reference to null?
View 3 Replies
Mar 13, 2012
Okay, I was doing a lot of research this morning and found what I hope to be a promising example (code and installation file in the zip folder I downloaded). Even though it is from 2005, and I am working with 2010.I had to update/upgrade the entire project to view the code, and... ok, I am just rambling.I know how to set the filters for SaveDialog and OpenDialog (took me a long while to understand, but I now understand it), but when I finish and build the project to host it on CNet Download or somewhere similar.
View 3 Replies
Mar 27, 2011
how can i use value (23,32) in sql column datatype int how can i use comma in column data type int
View 8 Replies
Sep 27, 2009
I don;t know what datatype while storing the data of datetimepicker in vb.net. The tools i use is sql server.
View 1 Replies
Jun 20, 2012
I have a window application created in VB.net 2005 and the backend is sql. I make a call to the database and it returns a datatable. When I loop through it, I get a value of -1 for my field "Rush" which is a bit datatype. when I pass the sql into the analyzer, I see the value should be a 1 so not sure why it's giving me a -1. Here's some of the code that's in the page: Dim tblSendEmail As DataTable
tblSendEmail = oService.GetSendEmailInfo 'Goes to a webservice and returns a record set in the datatable
For Each row As DataRow In tblSendEmail.Rows
iRush = row("rush")
next
[Code]...
View 1 Replies
Sep 15, 2011
I have the following line of code:
CType(IIf(CBool(product.IsDiscontinued Is Nothing Or product.IsDiscontinued = True), False, True), Boolean?)
What does the Boolean? mean at the end. I have seen it used on other data types as well.
View 3 Replies
May 16, 2011
I have the following script which works, but I don't understand why it will not work when the type is set to json:
Serverside:
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs)
Response.Clear()
Response.ContentType = "text/plain" '//#### <- should't this be text/json? ###
[Code]....
When I change those values to json, the whole thing stops working and returns "null"...
View 3 Replies
Nov 8, 2010
I am converting the database in an application in Visual Basic 2008 from Access 2000 to SQL Server express 2009 R2 database. There are several fields that "SmallMoney" seems the mos appropriate to use. When I try to use the "SmallMoney" datatype in a Parameter, it won't accept it, the datatypes listed when I try to indicate the datatype does not inclue Mone or SmallMoney. It does include "Currency".
However the ere doesn't seem to be a "Currency" data type in Visual Basic. Would I be better of using Double and change the table definitions back to Double as they were in Access?
View 2 Replies
Feb 15, 2011
Just come across the following snippet:
Public Function Checked() As Boolean
Return applyChange 'this is a string!
End Function
Whats going on here? How can a function with return type Boolean actually return a string? I'm assuming theres some implicit conversion going on here, which I'd rather not have.
View 1 Replies
Dec 13, 2011
This is just a quick question: Are there any difference between
[Code]...
View 3 Replies
Jan 5, 2009
I have a datatable that I read xml into.
One of the columns is a date, but the dataype of that column is set to string. Is it possible to change that dataype to date?
View 10 Replies
Jun 21, 2010
as the title states. Is there a way to determine if both datatypes are the same?
View 2 Replies
Jul 25, 2010
I have a boolean check property of my check boxes in VB.NET. how can I send that value to SQL server having a bit data type
View 4 Replies
Mar 30, 2010
Just got an overflow issued and found that it was about the datatype. I fixed it and test it around
Change the datatype of Int32 to
1. UInt32 - 32bit
2. Double - 64bit
It works fine in my side. UInt32 Length should be long enough for me. I am thinking to use UInt32 as it "saves" more disk space (or probably runs a bit faster). However, what is the drawback if I always use Double ?
View 9 Replies
May 1, 2009
is there a datatype available in visual basic that can be used to store dates?
View 4 Replies
Oct 20, 2010
I'm using two DateTimePickers to represent 'StartDate' & 'EndDate'. On initialization I set the StartDate control to today's date at 12:00 AM. I do that like this;
[Code]...
View 7 Replies
Sep 21, 2011
i have been redirected from the vb.net technet forum to use asp.net forums instead.
I am using some COM components within an asp-page or vbscript. As an example the code flows like this in vbscript:
set objectA=CreateObject("SomeComponent.A")
objectA.PropertyA="Some String"
objectA.PropertyB=ValueA
set objectB=CreateObject("SomeComponent.B")
set ObjectC=ObjectB.MethodA ObjectA
This code works fine and i can continue with the data in ObjectC.
Now i want to change this into ASP.Net with VB. If i open the COM type libraries in Oleview32, the datatype expected in MethodA is VARIANT. So i tried to pass into a type of Object in MethodA. This leads to an exception and code stops.
Is there a way to determin or to trace what vbscript is passing into MethodA so that i can get an idea of how to prepare the datatype i have to pass into the method-call? Are there any tools for that? So ctypeing to an object does not do the trick. A better documentation about the COM Object is not available.
The first reply from the vb.net guys was´, if the COM libraries can be hosted on iis? So, they are used excessively within asp pages on iis 7.5, if they can be used in asp.net, i don not know. I am not a developer but i have good understanding in writing code and using asp.net.
View 1 Replies
Nov 26, 2009
I have a field in a SQL Server table that is of type bit.When I try to use a Boolean in VB.NET when passing parameters to a stored procedure, there are never any matches. I have also tried passing an integer to the stored procedure and that does not work either.
View 4 Replies
Dec 22, 2011
Function returning different datatype
View 4 Replies
