I tend to use
If Not IsDBNull(dr("data")) Then
myData = dr("data")
End If
to catch nulls. Is there a better way? It seems I use this over and over again? Anyone write a function to check this something like
mydata = IfNotNull("data")
I don't know how to handle the different data types that could be returned.
When the AlertsSettings.xml is not present the Appsettings is assigned to nothing. The variables that follow that definition rely on the existance of that information which will normally be set by the load method. But when there is a problem and either of the variables do not get a value how do I handle that in the code that relies on those values. The Settings class deserializes an xml document and assigned values to properties.
Sub Main()
Dim Appsettings As Settings = Settings.Load("AlertsSettings.xml")
Dim AlertsServer As String
[Code].....
I have the following statement, I want to turn it into a Public Shared Function :
If isEmployee Then
Dim employeeInstance As New Employee
employeeInstance = GetEmployeeInstanceByUserId(userId)
[Code]....
Public Shared Function GetWorkerInstance(Byval isEmployee as Boolean) As ...(not sure what to write here)...
There two possible return Type. I'm not sure what I should declare for the function return type.
I have an application which runs during all the user's session. If the application is closed by the user everything is fine because the app goes to "ON_EXIT" event and does its job. If the application is terminated by TaskManager or by a System Shutdown... well this last part is skipped and my app can't complete the requested operations.
View 2 RepliesI am confused which data type to define for my variable which stores value returned by LINQ Statement.
Currently I am defining it as some data type but its generating error like: ""Unable to cast object of type 'WhereSelectListIterator2""`
[Code]...
Here i want myBase to hold the data which has UIN = 4
I am returning a date from my database table:
objSQLDataReader("date")
Which gives me:
31/05/2011 16:00:50
How do I change this to:
31 May 2011
I have a asp.net page that has several SqlDataSources defined that feed data into some graphs. The problem is that the graph product does not handle "no data" very well, and throws an error. I'd like this to handle the situation more gracefully-- so I need to check whether the SqlDataSource returned data or now before rendering the graph (and if not, just post a message saying "No Data" or something).
Is there an easy way to check if the data source returned data, and do this if/then without a bunch of code behind?
I am inserting a record in an SQL table and trying to get the record ID back so I can use it to insert subsequent/related records in another SQL table. I am missing something but have no idea what. Code is below.
<asp:SqlDataSource id="SqlDS_HydInspection" runat="server"connectionstring="<%$ ConnectionStrings:
MenomoneeFalls_DB3ConnectionString %>"
[Code]....
I'm sure im just making a simple mistake some place but i just cant find it. I have datatable which I can and can make changes, save back to the database just fine. But if I reload the data after updating, no data is retrieved from the database. But if I stop debugging completely and then start again, it loads just fine...until i call Update.
Here is some code I am using for testing purposes.
Private myDataSet As New DataSet
Private conn As MySqlClient.MySqlConnection
Dim myDataAdapter As New MySqlClient.MySqlDataAdapter
[Code]....
In VB.NET I would like to create a complicated data structure with multiple types of data stored in an array like format (see below). I am trying to create a data structure that would look something like this: [Name; xLoc; yLoc; zLoc; [Jagged Array]] Note: Name needs to be dimensioned as a string, xLoc and so forth as integers. The Jagged Array would look like this:
[Code]...
I am calling an Oracle function PKGDummy.F_EMPDATA using vb.net.
View 1 RepliesUsing Visual Basic 2008 How can i read data returned from the serial port . also how can i clear the buffer.
View 6 Replies[URL] Using this I have managed to use Server Side Web Methods to perform actions with AJAX.In most instances, I just need it to do stuff (save things to a database for example) so don't need to do anything with the response, but now I've come across a situation where I do, and I can't work it out!The Web Method returns a JSON object, which looks like this:
{"d":"[{"validDetails":"True","lateAlert":"","LoginResponse":"Logging in Jamie at 16:53 please wait"}]"}
This is the output shown from Firebug. I am not sure what the 's are, but bear with it...The AJAX call and attempt at outputting this response is:
$("form").on("submit", function () {
var LogonObject = new Object;
LogonObject.password = $('#password').val();
[code]....
And several other variations from info I have found on Google and SO, but it seems to treat the results variable as a string, not an array, and the output I get on the alerts is each individual character, ie;
[, {, ", v, a, l, i, d, D... etc
So I wondered if results needed to be converted to JSON again (though I don't know why) so I tried
results = $.parseJSON(data.d)
But that didn't work either.
EDIT, the code which generates the response (missing out tons of logic, but this is the important bit):
Public Class OutputObject
Public validDetails, lateAlert, LoginResponse As String 'content of JSON output'
End Class
[code].....
I have the following code to bind data to my form controls:
dateFromDate.DataBindings.Add("Value", dvUpdateCME, "From Date")
dateToDate.DataBindings.Add("Value", dvUpdateCME, "To Date")
[code].....
how to read all the tables returned by SQL Stored Procedure? My Stored procedure returns two tables:
ID Name
-----------
1 Jeff
2 Joe
[code]....
i want to read data from both of these tables. I tried using SQLDataReader and then populating into datatables but then i can only read the values of 1st table. I want to read both the table values. How do i do it?
I have been prototyping a simple site search tool.I found some online references to using webclient.download data. I have a (mostly) working prototype, but it only returns static HTML on the page that is being searched.I also would like to be able to search the contents of controls (such as text in label controls that are set at run time.) In the code below, the data in label1 is not returned.[code].....
View 3 RepliesI have two functions written in VB.NET:
1) The first function (call it GetValues()) returns values in a SQL database as a list via a stored proc. One of the fields is DateTimeSubmitted. All of this data is displayed on my webpage using a repeater control. It works fine.
2) The second function (call it NiceDate()) I created to change the DateTimeSubmitted to a nice date such as "one minute ago" or "yesterday".
My problem is I have no idea which is the best part of the process to do the conversion (at point of data extraction or in pageload etc.) or in fact how to do the conversion.
Can any one provide me the link or give me an idea how to read all the tables returned by SQL Stored Procedure?
My Stored procedure returns two tables:
ID Name
-----------
1 Jeff
2 Joe
ID Pages
----------
1 2
i want to read data from both of these tables. I tried using SQLDataReader and then populating into datatables but then i can only read the values of 1st table. I want to read both the table values. How do i do it? please let me know if you guys have any ideas how to deal with this.
So I have a relatively small website with growing amounts of data - the fastest growing table is pageviews, as we do all our analytics ourselves. The website is made using VB.Net, SQL Server 2008 and jQuery. I am limited to .net 2.5.I currently handle all the data and validation using objects with a list of attributes. Each attribute is of a specific datatype and has a validation function when a new value is given to it. If the data does not validate then it won't even get as far as updating the database and feeds back an error to the user. Currently I have "Manager" classes and "Item" classes - Items are managed by a particular Manager class, for example Users are managed by the UserManager, so to get all the users I just have to call UserManager.Items. These Manager classes are stored in the cache and are created as needed - but once a Manager class is referenced it creates all of the Items within it. This is getting rather slow now, as the company is growing fast. It takes 2 - 3 seconds to load the first page (the page which makes most first-time requests to data) but I am not happy with this time. After that it is nearly instant.
Now the way I see it I have 3 options to speed the website up: Keep it as it is, but try to make it more efficient through other techniques;Change to creating all these objects on every page load, in the hope that it is simply so slow because I am using the cache to store a fair amount of data (about 10 MB or so at least);Forgetting using object oriented techniques and just use straight SQL queries and loop through records.
I am trying to read some data from an Excel 8.0 worksheet using OLEDB thusly:(Warning - contains curly braces)
Code:
DbProviderFactory factory = DbProviderFactories.GetFactory("System.Data.OleDb");
using (DbConnection connection = factory.CreateConnection())
{
[code]....
The problem is that for some columns it sets the data type to be Double even though the spreadsheet column format is "Text" and teh column contains non-numeric data. Then when it gets to that cell it returns DBNull instead of the text value.
SQL Server has a Data Type of "Float". Visual Studio has a Data Type of "Decimal". In other words, if I have a variable in a VB.Net app that is defined as a "Decimal" ...can I move that value into a SQL Server Data Table column defined as a "Float"?
View 4 RepliesI have been trying for days now how to create a process to the user to easily create a connection to any installed data types they have installed. I have found an example right inside vb2008. I never use this because I code my own connections, but this would be real nice if I could include it or duplicate it.
View 1 RepliesI'm trying to call a C++ DLL from inside VB.NET and am having difficulty with the data types (I think), I understand VB.NET far more than I do C++...I think my main problem is differing data types and I don't understand enough C++?In C++ the DLL is called (I don't have the source for the DLL which would solve my problem, I only have a sample project written in C++) by this;
_InitSensor = (InitSensor)GetProcAddress(m_hInstLibrary, "InitSensor");
_FreeSensor = (FreeSensor)GetProcAddress(m_hInstLibrary, "FreeSensor");
_ReadTEMPsh10 = (ReadTEMPsh10)GetProcAddress(m_hInstLibrary, "ReadTEMPsh10");
_ReadType=(ReadType)GetProcAddress(m_hInstLibrary,"ReadType");
(Variables Declared Previously in other file like this;)
typedef char* (*InitSensor)(char ICType);
typedef void (*FreeSensor)();
typedef double* (*ReadTEMPsh10)(BYTE n);
typedef double (*ReadType)(BYTE address);
I use Philip's MfRc500.dll for communicating with RFID chips. It contains a function for reading data, which is defined like this:[code]The second parameter in function Mf500PiccRead can returns "16 byte data block", so my long data type is too small. If I use byte() instead of long, then i get ExecutionEngineException Exception.
View 3 RepliesI'm torn between using UniqueIdentifiers(UID) or some other field as my primary key for my new web app. I have two tables. I need to be able to find the UID on one record in Table1 and put that UID in a new record in Table2. I also need to be able to create a brand new UID for the new record in Table2 on the fly.
View 3 RepliesVisual Basic 2010 (Express). If I take a string from a textbox and assign it to an integer variable, I'm under the impression that you're supposed to use CInt to explicitly convert the contents to an integer.intMyCount = CInt(txtUserInput.Text)However, if I don't do that, it still seems to work. Similarly, if I have an integer and concatenate it into a label's text property, it still works: lblResults.Text = intMyCount & " number of times."
rather than using intMyCount.ToString.Why does it work? Is VB doing implicit conversions when possible? Are there examples where not explicitly converting with .ToString or using CInt would cause unexpected results?
I am trying to wrap a c++ dll and can use system.runtime.interopservices.dllimport and declare function to call functions from the dll. But how do i wrap the data types and everything else?
View 1 RepliesI want to compare two objects whose type may be diffrent.
For eg, I expects 'true' for comparing 1000.0(Decimal) with 1000(Double) . Similary, it should return true if I compare 10(string) and 10(double) .
I tried to compare using Object.Equals() , but it did NOT work.It return false if two objects have different data types.
Dim oldVal As Object ' assgin some value
Dim newVal As Object 'assgin some value
If Not Object.Equals(oldVal,newVal) Then
[Code]....
I am create a mysql table with TIME data type Field. And then store time type data into that field. But can't view in datagridview ( not show in other controls, like LABEL,TEXT,LISTBOX etcc..) . Using method is:
(LEAVEFROM TIME DATA TYPE, LEAVETO TIME DATA TYPE)
Dim cmd As New MySqlCommand
Dim adapter As New MySqlDataAdapter
Dim table As New DataTable
[code]....
Run time display error:ArgumentException was unhandled Argument 'Prompt' cannot be converted to type 'String'
I have a table that has a "date" column and an "amount" column. I also have a form with two DateTimePickers ("dtp1" and "dtp2"), a button and a label. The label should show the total amount calculated from the rows whose "date" value is between the dates picked by the user with the DateTimePicker controls.
I keep getting an error with my SQL statement, and I don't know what to try. My code is as follows:
Private Sub getData(ByRef total As Double)
Dim connection As OleDbConnection
connection = New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\proyectogestion.mdb")
[Code]....