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Hi all,
My Application gives me an error of type "Cast from type 'DBNull' to type 'String' is not valid" when some value in the select statement is stored as "<null>" in the SQL Server 2000.
How could I return a "<null>" value from database, or is there a way to convert a value stored as "<null>" to any other value (example: zero or space)???
this is the sql statement in my web application:
Dim com As New SqlClient.SqlCommand
Dim ds As New DataSet
Dim da As New SqlClient.SqlDataAdapter("select X, Y, Z from hotels where X=" & Me.Xtxt.Text, con)
da.Fill(ds, "hot")
Note: This statement has no errors and works fine when no column in the database has a value "<NULL>".
Kind Regards
OBarahmeh
Palestinian Central Bureau of Statistics (PCBS)
Ramallah-Palestinian Territory
modified on Wednesday, March 12, 2008 9:39 AM
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Yes there is ways of converting the data once it is brought back from the database using c# code.
Can you explain more?
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I can 100% sure that the above doent produce any error. you may use some varriable to assing the returned value. There only you will get these error. Use Not .DBNull("ColumnName") function while assinging the value to a string
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I have edited my question, could you please see my question again.
some of data in the SQL server 2000 has "<NULL>" value.
When I execute the above statements in the case there is "<NULL>" value in some field, then the above error happens: "Cast from type 'DBNull' to type 'String' is not valid"
 
Kind Regards
OBarahmeh
Palestinian Central Bureau of Statistics (PCBS)
Ramallah-Palestinian Territory
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<b>a-+s-+p-+ wrote: Yes there is ways of converting the data once it is brought back from the database</b>
I want to convert the data (value), i.e: if the select statement return the value of some field as "<null>", I want to convert this value ("<null>") into zero.
could any one do this please?
Kind Regards
OBarahmeh
Palestinian Central Bureau of Statistics (PCBS)
Ramallah-Palestinian Territory </null></null>
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You jus need an if statement saying
if(columns.value = null)
{
}
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Could you please tell me how could I apply this to my statements:
Dim com As New SqlClient.SqlCommand
Dim ds As New DataSet
Dim da As New SqlClient.SqlDataAdapter("select X, Y, Z from hotels where X=" Me.Xtxt.Text, con)
da.Fill(ds, "hot")
Kind Regards
OBarahmeh
Palestinian Central Bureau of Statistics (PCBS)
Ramallah-Palestinian Territory
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My web page contains an image button enclosed within div tag and a list box. On page refresh, a wait message will also be displyed. But during refresh, the list box flickers, its size gets changed and part of wait message window goes behind the list box. Could anyone please help on this?
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you could try setting the focus on the listbox on the page load or
try this: VisibleDuringInit = false for the listbox
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Hi All,
How to set colors of sidebar navigational links in wizard control dynamically
Regards,
Venkata
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Hello Freind...
<!-- main calendar program -->
<SCRIPT src="js/calendar.js" type=text/javascript></SCRIPT>
<!-- language for the calendar -->
<SCRIPT src="js/calendar-en.js" type=text/javascript></SCRIPT>
<!-- the following script defines the Calendar.setup helper function -->
SCRIPT src="js/calendar-setup.js" type=text/javascript></SCRIPT>
<SCRIPT type=text/javascript>
Calendar.setup({
inputField : "StartDate", // id of the input field
ifFormat : "dd-mm-y", // format of the input field
button : "f_trigger_startdate", // trigger for the calendar (button ID)
align : "Bl" // alignment (defaults to "Bl")
singleClick : true
});
SCRIPT;
this code runs perfectally in simple page.. bUt its not run in content page when we use master page....
Please suggest me what will i do.....
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ASP.NET prefixes the container id along with the control id. So when page is rendered, your controls id would be different. So always use ControlName.ClientId.
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please explain... this is not working..........
How can i use this Controlname.ClientId in this script....
for server control in master page.....
if i use html control then its working properly but when i add the runat="server" then throw error 'value' is null or not an object.
suggest me.. how can i do....?
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You can take the client id of a control in javascript like the following
var controlId = '<% TextBox1.ClientId %>' ;
var controlObject = document.getElementById(controlId);
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Hi All,
I m downloading a page from FTP SERVER,
while downloading , firts it shud download to server(local) and then prompt a save-as dialog box,
it getting saved on server, and also prompting the save as but when i click open directly without selecting any location to save in the local hard disk, its giving an error as file not found exception(only poping up a message, application is un interrupted)
any one tell me that y its prompting that file not found msg, eventhough after saving this file to server,
whether any path problem while opening directly?
i 'll b thankful for all solutions and suggestions.
Thanks in Advance
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What it has to with ASP.NET ?
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i have a class which contains some functions
like
Public string Mystring()
{
return "as";
}
public string getString(string x)
{
string str="";
str=x;
}
Now what i want to do is i have added a text box to check the syntax i want to write a call to functions if i write some thing in the textbox on button click it should be checked whether the call is correct or has error.
e.g if i write
getString("sdsd"); or
getString(Mystring);
it should indicate that the format is correct
and if i write
getString(23);
it should indicate that not a correct call as it is not correct
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If you use the getString(22) the compiler will itself throw an error msg
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Waheed Ur Rehman wrote: getString("sdsd"); or
getString(Mystring);
Will you write getString("something") in the textbox, or in code file ? If you are writing it on textbox, you need to parse the text with regular expressions, take only the values inside brackets and check for valid value.
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i have to write in the textbox not in the code file
thanks for response and waiting for response
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Use regular expressions to get the item entered in between brackets. Then check for data validity. But your problem looks strange to me.
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if in the brackets i have anoter function and so on then what to do
i think if i make the textbox text execute it can check but how can i make it a code statement which will execute on button click
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Waheed Ur Rehman wrote: if in the brackets i have anoter function and so on then what to do
Your expression should be able to look for the text inside the outer brackets.
Waheed Ur Rehman wrote: i think if i make the textbox text execute it can check but how can i make it a code statement which will execute on button click
This is an alternative approach. You can use reflection to invoke the method. This[^] article explains it.
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Hi...
I am developing a project called Info Dial....I got stuck at a place where i have to store an excel sheet into a database that can be displayed in a grid view....thats working fine for a single Excel sheet...but what if i have more than one excel shhets  ??How can i overcome this problem?
I have my code as shown....
if (FileUpload1.PostedFile != null && FileUpload1.PostedFile.ContentLength > 0)
{
string fn = System.IO.Path.GetFileName(FileUpload1.PostedFile.FileName);
string savelocation = @"D:\programs\" + fn;
FileUpload1.PostedFile.SaveAs(savelocation);
string excelConnectionString = ("Provider=Microsoft.Jet.OLEDB.4.0;" + "Data Source=" + savelocation + ";" + "Extended Properties=Excel 8.0;");
// Create Connection to Excel Workbook
OleDbConnection connection = new OleDbConnection(excelConnectionString);
OleDbCommand command = new OleDbCommand("Select * FROM [Sheet1$]", connection);
connection.Open();
// Create DbDataReader to Data Worksheet
System.Data.OleDb.OleDbDataReader dr = command.ExecuteReader();
// SQL Server Connection String
string sqlConnectionString = "Database=Infodial;server=s156;uid=sa;pwd=sa";
// Bulk Copy to SQL Server
SqlBulkCopy bulkCopy = new SqlBulkCopy(sqlConnectionString);
bulkCopy.DestinationTableName = "companydetails";
bulkCopy.WriteToServer(dr);
connection.Close();
ScriptManager.RegisterStartupScript(Page, this.GetType(), "alert", "<script>alert('Saved in Database Successfully');</script>", false);
}
Any code would be appreciated...
Thanks in Advance
Regards
Abhishek.
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Hi all,
I am gettting the invalid charcter error msg
<button onclick="__doPostBack('btnClear','')" id="btnClear" class="btn" title="Alt-C" accesskey="C" style="width: 56px">Clear</button>
<button id="btnSave" runat="server" class="btn" onclick="btnSave_OnClick" type="button">Save</button><br />
Can some one help ?
Dana
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