I have remplace the keyarr definition by my SQL query: With the code above, I can print both keyarr in a console. What should I change in the _sqlReader.Read() function in order to get keyarr definition like the first code. I would like that keyarr could be
interpreted by the rest of my code.
i wonder if it's possible to define a variable/property of more than one type. Let's say i want a property TextWebControl that is a WebControl and also implements Web.UI.ITextControl(f.e. like a TextBox or Label). But i don't want to enforce that it is a TextBox or Label, but only one that inherits from WebControl and also implements ITextControl so that it also would work with controls added in future releases of .Net-Framework.
.Net-Framework 4.0
Edit: I have retagged the question and added VB.Net because it's my default language. Normally it's no problem for me to understand C# also, but i must admit that it's difficult to translate generic stuff to VB.Net without experiences and it's also better documentated in C# than in VB. So i would appreciate(and aceept) a working example of a VB.net generic type of ITextControl/WebControl.From Marc's answer i understand that i need a generic class. But how do i instantiate it in SomeClass? This won't compile:
Class SomeClass Public Property info As InfoControl(Of WebControl, ITextControl) End Class Public Class InfoControl(Of T As {WebControl, ITextControl}) End Class
I have no idea as to how I can define a variable as "GLOBAL" in VB Express 2008. I used VB V 3.0 and if I remember correctly the statement "Global varName as Integer" allowed me to use the variable across different forms. I've tried the statement "Public varName as Integer = 0" on Form1 but Form2 tells me the variable is not declared.
The statement (in Form1) "Form2.Label1.Text = CStr(varName)" displays the value on Form2 in Label1 but I cannot then use the value again in Form2, e.g. "Label2.Text = Label1.Text". How I can transfer a variable value from one form to another and manipulate that variable in the second form?
Im trying to grasp session varibles, i understand what they are etc but i would like to know how to define a type for each session variable.Iv written it like this
Session("Title") = txtTitleContent.Text
How can i tell it what type of value is going to be in it, because at the moment im only playing about with strings, but what if i have an integer and want to pass it back to the back end to save it will throw an error saying "conversion from string to integer is not valid" should i use Cint to deal with this?
Is it possible to define a datagrid and chart name as variable? I'm planning to put the result into the predefined datagridview inside FOR and NEXT loop. I've been trying but getting different sorts of errors..
I am getting the error:"Range variable 'sender' hides a variable in an enclosing block or a range variable previously defined in the query expression."for this
Imports System.Data.SqlClient Imports System.Linq Public Class Form1
[code]....
I can select any other item from the table without the error. "sender" has the same properties as "receiver" in the SQL table.
I am trying to run a query an Access db from VB. The general query which I want to run is
SELECT * FROM Patient WHERE Patient.PatientID = ? or SELECT * FROM Patient WHERE Patient.PatientLname = ?
I tried using an input box which captured the user input and pass that variable to the query, but that failed. Then I read about writing a function and using that, however, I keep getting an error which says Function not defined, but when stepping through the code, it seems to work. Here is my function: [Code]
The company I work for has an application where various users can log in and add their own "clients". Currently, via sql mail a confirmation email goes out to the client who has been added but the "From" value is generic i.e.Admin@CompanyA.com. What we need is a way for an email message to be sent to the new client but have the "From" email be that of the user adding the new client. When a user registers to use our system they supply basic info including their email, so when they log in and then add a client we would like to have an email sent to that client but have the "From" address be that of the logged in user instead of the generic one from our company. The email would have to be sent from our company's server but we want the sendee to be able to directly "reply" to the sender's email.
In one function I have the variable: dim StrProjectNumber = UCase("23-EXP-16284")
However in another form I want to use that same variable in a SQL query, and when I try it says the variable is not declared. Do I have to make a global variable or is there a way around it? If so, how would I go about declaring a global variable?
In other languages, I believe it was a good practice to also define the type of variable it would be, for performance or something. I am not entirely sure with VB.NET.
I'm trying to get some data from an access database and show them in a CheckedListBox The sql quary includes a variable('sport') and it's values is passed by the user when I run the following code an exception is thrown at the line adStudentList.Fill(dsStudentList, "Register") and it says 'no value given for one or more required parameters'
Dim adStudentList As OleDbDataAdapter Dim dsStudentList As New DataSet Dim sport As String sport = cmbSportList.SelectedItem
I am trying to get the value of a Query and save it to a variable, The only way i have been successful is through creating a loop and then saving the value of the location...
Below is the
Dim DBConn As OleDbConnection Dim DBCommand As OleDbDataAdapter Dim DSPageData As New DataSet
By this way combobox CmbId is storing above sql query ouput. But now i want to get above query ("Select Name from StudentDetails where Id=10 ") result to store in a variable string. How can i do this ?
I have 2 public variables that I declared in form1 of an application. I am trying to call that variable in form2 and then pass that variable in a sql query. [code]...
How do I assign the query result to a variable.I am using SQLlite. Below is the code for retrieving password from the User Table. I need to compare the given password and the given password.
Dim i As String Dim p As String i = txtUserID.Text
I have a public variable that I declared in form1 of an application. I am trying to call that variable in form2 and then pass that variable in a sql query.
If I declare
Public Class Form1
Public payPeriodStartDate, payPeriodEndDate As Date
How then to I declare that variable in form2 and how to I pass it to my sql query
SELECT [Exceptions].Employeenumber,[Exceptions].exceptiondate, [Exceptions].starttime, [exceptions].endtime, [Exceptions].code, datediff(minute, starttime, endtime) as duration INTO ScratchPad2[code].....
I have 2 public variables that I declared in form1 of an application. I am trying to call that variable in form2 and then pass that variable in a sql query. [code]...
I have a public variable that I declared in form1 of an application. I am trying to call that variable in form2 and then pass that variable in a sql query. If I declare:
Public Class Form1 Public payPeriodStartDate, payPeriodEndDate As Date
How then to I declare that variable in form2 and how to I pass it to my sql query.
Here is the code I have for form1: [Code]
and when I debug this form, no data will appear. I'm sure that it's something wrong with how I'm either calling the variable in form2 or in the query. Can anyone offer any assistance on this?
I am using VS 2010, SQL 2008 express and doing windows applicaion programming in vb.net.I want to write a select query(or Stored Procedure) such that the conditions mentioned under WHERE clause can be variable .like :Select * from TABLE where F1 = var1 and F2 = var2 and F3 = var3.Now on the basis of some conditons the equations in where clause should beused.Say condition is variable value >6.Now in this case ,if
var1 =7 var2 =3 var3 = 8 then the query shud behave like : select * from TABLE where F1 = var1 and F3 = var3
This is probably so simple however my brain has decided it wants a night off. I am trying to write a program that uses SQL queries for various tasks but I need it to allow the user to be able to use which ever name they want for the database name. therefore I need to be able to reference the database as a string variable. For Eg:
I'm just wondering if it's possibe to get the results from a query and then assign the results to a variable. So I will run a query which will return the names of the tables stored in the database, then I want them to be stored in a variable. So it would be something along the lines of:
Dim strFrom AS String = "FROM " strQuery = "SELECT * FROM information_schema.TABLES WHERE TABLE_SCHEMA = 'Database1'" con.Open()
I want to query items from countries that are selected from a treeview (with checkboxes). However the number of countries that is selected by the user is not known beforehand. So how can I make a proper query when the number of OR operators is unknown? For example: SELECT DISTINCT Item FROM Countries WHERE Country LIKE @c1 OR @c2 OR @c3 etc� and then add the parameter values based on the selected countries in the treeview. I looked into parameter arrays but can�t make sense out of it really