I there a way to set up my DataTable so a field (or all fields can allow nulls if you can't set just 1 field) so oIDbDataAdapter.Fill won't leave out DataRows where a field contains a null value?
Dim oSqlCommand As SqlClient.SqlCommand
Dim oIDbDataAdapter As System.Data.IDbDataAdapter
oSqlCommand = New System.Data.SqlClient.SqlCommand( _
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I require the expression which determines if a Data Item in a DataRow is null.
Required Code
If MyDataSet.Tables("MyTable")Rows("MyRow").Item("CheckingItem") [IS NULL] Then
'[Do Something]
End If
Attempted Code Resulting in Thrown Exceptions
I have attempted the following code which resulted in the exceptions posted under them.
If CType(ds.Tables("MyTable").Rows(0).Item(2),System.String) = "" Then
Me.lblOutput.Text = "Good"
End If
System.InvalidCastException: Conversion from type 'DBNull' to type 'String' is not valid.
I am trying to add a parameter to a sqlDataAdapter. I have tried to use parameters.add() but the adapter is not a sqlCommand. Here is some of my code.
Private Sub convertToCSV(ByVal SqlQuery As String)
Dim Dt As New DataTable()
Dim SqlCon As New SqlConnection("Data Source=db;Initial Catalog=productionservicereminder;User Id=id;Password=pass;")
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Basically I am trying to do something like this:
Ada.Parameters.Add(New SqlParameter("@pgid", pgid))
I have to copy the contents of one row in a table to another row, there is no problem until the source has no image so its value is Null, which is allowed in the SQL Server database.[code]....
View 2 RepliesThere is no other workaround at this point, so here is what I am attempting to do:
1. Fill a DataAdapter from an Excel.xls spreadsheet.
2. TRUNCATE an existing SQLServer2005 db table that matches this excel spreadsheet.
3. UPDATE that SQL Table with the DataTable filled from the excel spreadsheet.
If there are anyother suggestions (OPENROWSET/DATASET is not possible for my situation, in or outside of a SProc),Here's the current dev point I am at --- no errors, but also the SQL table does not update.
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I have a problem with access database in my vb project. I would like to fill the listbox with objects from my database. I've attached two images. In first image when i'm using command objDataAdapter.Fill(mydataset....) i can select table property(zaposlen). But in second image or in my second app i dont have an option to select table property in my dataset(there is nothing to select). If i select DataTableDataTable i get next error: DataTableDataTable' is a type in 'WindowsApplication1.baza_podatkovDataSet' and cannot be used as an expression.
View 2 RepliesWhen I use the dataAdapter.fill(ds,tableName), it reports an error: "Failed to enable constraints."Yes, I changed the selectcommand.I know if I modified the selectcommand, and if it will take diffrent columns result, this error will be reported.
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i try to use this yesterday it work fine..now, it will process too slow.. when fill the dataadapter into the dataset..here is the code it gives 20 menutes still no result.. "no error, no comment. it's like standby
Dim conn1 As MySqlConnection = New MySqlConnection("server=pc1;user id=user;Password=12345;persist security info=True;database=mytsmobile")
conn1.Open()
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[code]Where I add my parameter, I am trying to have it pull records that contain the text that is in the jpDescTextBox instead of being exactly equal to it. I have tried using wildcards such as * and %.
View 7 RepliesVB2010, MySql I have a dataview generated from a datatable using a rowfilter.I have event handlers listening to the dataview.listchanged event. To keep the datatable (in memory) in sync with the mysql database (on a remote server), i issue datadapter.fill commands every now and then, the objective being that only the changed rows in the datatable (as a result of the fill) would generate a listchanged event on the dataview.To my surprise the dataview_listchanged event fires after refresh by the dataadapter.fill method, however the ListChangedType it gives is: ListChangedType = reset. I would have expected a ListChangedType.ItemChanged for every changed datarow.Since the dataview is used to populate a large storage yard, i am now forced to repopulate the whole storage yard, which is a time consuming business.Is there a way to only generate DataView.ListChanged events for rows in the datatable that are actually changed by the datadapter.fill method?
View 2 RepliesI am having trouble setting a datetime column in a datarow to null or MinValue and updating the database row using a DataAdapter update command.In one scenario, if the value in a text box is not a valid data, I set the value in the datarow = DateTime.MinValue. The value returned by MinValue is #12:00:00 AM#. An error is thrown on the Update command "SqlDateTime overflow.Must be between 1/1/1753 12:00:00 AM and 12/31/9999 11:59:59 PM."
In another scenario, an error is not thrown but the DateTime value on the row is not changed.The database column allows nulls and I can set the value to null using a SQL update command.
At the top of my code for the form I have the following statements (and some other unrelated ones to):
Dim LastDataRow As DataRow
Public Event RowChanged As DataRowChangeEventHandler
When my form loads I run the following line of code:
AddHandler dt.RowChanged, New DataRowChangeEventHandler(AddressOf Row_Changed)
After the form loads I have a FetchData button which connects to the database and brings the records into a datatable object. During this fill operation my Row_Changed event fires (for every record I think) and tries to run DataAdapter.Update(DataTable) (pseudocode) which ultimately fails because I haven't yet created commands. The error I get in my Row_Changed procedure is:
Update requires a valid InsertCommand when passed DataRow collection with new rows.I hadn't even planned to use an InsertCommand at all since I will not be allowing users to insert records from this form. I do plan to allow them to delete or modify existing records, but not insert new ones.run my AddHandler statement after filling the datatable. However, I'm trying to figure out how to rewrite my code so that I can refresh the datatable without closing out the form/application and having to open it up again. I think that's a problem for a separate discussion.
I am building a data based application using VB 2008 an SQL Express. I need to create textboxes on my form using code, (With & End With) method. I need a simple code string that will allow the app to check if the field to wich the textbox wil be databound is Nul, If so the textbox will not be created.
View 8 RepliesUsing VS2005, VB.Net, Dot Net 2.0, SQL Server 2000. If have some Columns (varchar and numbers) in a DataRow that I want to set to DBNull in the database. The fields as defined as Nullable in SQL DB table.
I have some fields that are populated when loaded but I want to update to be null using the ADO.Net data objects. If I try and use Row("FieldName") = DBNull.Value a 0 gets written to number fields (not sure what gets written to varchar fields.) What code should be used to update fields to Null using ADO.Net dataobjects?
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I posted in the Database development forum, but no bites. I have field names in my Access table which have a number as the first character (i.e. "2x2"). Evidently, the DataAdapter doesn't like this. I'm able to view the data in a DataGridView, but I get an exception when I use DataAdapter.Update.
Can I modify my sql statement to make the command builder work or do I have rename the fields?
For example:
"SELECT [2x2] as twoBytwo..."
Changing the names of the fields would be a huge pain-in-the-arse!
I am looping through a dataset. I want to update a field in each datarow.
How can I edit a row in a dataset? I tried this but it didn't work:
For each datarow as datarow in dataset.datatable.rows[code]...
I am looping through the rows of a DataRowCollection and assigning the fields of each row to a variable. I always get "Input string was not in a correct format" no matter how I cast this. I just need gapCd to contain 0 if the field is null or the value otherwise. It seems the IsDbNull is not returning true properly. I've also tried DbNull.Value comparisons with no l
View 1 RepliesAfter running the following sub (VS debugger), I try to detach the database in SSMS, but it shows the connection open still and won't let me detach. If I close program in debugger, the database shows no connections. I check the dataadapter's connection in the finally block and is shows closed. What gives
Private Function ClientMasterDBFiles(ByVal MasterClientDBConnection As String, ByVal DBName As String) As DataTable
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With a Decimal, I use:
document.Air1 = CDec(IIf(Decimal.TryParse(Air1TextBox.Text, Nothing), Air1TextBox.Text, "0")) to fill the column with there is no value.
I would like to do something similar when the date is blank (preferably with NULL or just plain blank):
document.TestDate1 = CDate(IIf(Date.TryParse(TestDate1TextBox.Text, Nothing), TestDate1TextBox.Text, " - - ")) - of course, this throws an exception.
The table Data Type is date.
I have already defined in my SELECT statement in TableAdapter to tell it what to do if the parameters are Null:
SELECT a.ID, a.NameID, b.BNameID
FROM a INNER JOIN b
ON a.ID = b.ID
WHERE ((@NameID IS NULL) OR (a.NameID = @NameID))
AND ((@BNameID IS NULL) OR (b.BNameID = @BNameID))
I'm quite a newbie when it comes to coding. I am creating a bot to automatically fill in a form for me.I've got everything but the birthday down. When I go to debug, I select my month, date, year, and click the start button. It'll load the webpage but it won't fill in the year section of the birthday. I looked over the code and it looks fine to me.
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I using ADO to get som values from a SQL DB one off the fields can have the value NULL And if i use:
txtinfo.Text = RS(
"info").value
Then i get an error.I have try with IS NULL - but that dosn't work
how to delete row in a CSV file where there is a null value in a partcular column? I am using VB. There are three columns I am using Post Date, Account Number, and Credit Amount. I want to delete all rows with null values in the Account Number column. I am very new to VB, took one class. I am using the Microsoft.VisualBasic.FileIO.TextFieldParser?
View 1 RepliesI am using visual studio 2010. I have a text box bound to a sql datetime field.I have to be able to either set or clear the text box. I can set it to any date fine, but when I try to clear it I am unable to save the record.i am using the binding navigator to save.
View 5 Replieswe download a template form, prefill values which will be static, export a XML template
the XML is parsed with a .NET forms app, dynamic values are addedthe resulting XML needs to be imported back into the PDF templateAll goes well using the MergeXfaData method oniTextSharp, however for some reason, date/time fields are not being filled in (textfields and checkboxes work ok). Cannot figure out why. Searching through forums I discovered someone saying XFA only works for textfields. Why is this and how to work around?
I have a VBA program that automates an internet explorer process the whole code works except one piece.
when I try using this code,
Dim IEapp As Object
Dim IEdoc As Object
Set IEapp = New InternetExplorer
IEdoc.all("ctl00$ContentPlaceHolder1$uxQuantity").Value = 4
I recieve an error that says "Run-time error '91': Object variable or With block variable not set" I think there is something I'm not seeing with the site source because I use a similar code for a different website and it works.
In the past, I used the code below to fill out a form field using the webbrowser control in VB.Net. The page I am working with doesn't have name field for the inputbox, so my code doesn't work. How would I fill out the input box defined at the bottom of this post in bold?[code]...
View 1 RepliesLets put google.es as example. Google's field is called "q" (at least the spanish version).I have tried some code.
WebBrowser1.Navigate (google.es)
WebBrowser.Document.Forms(0).q.Value = "field text".
Ok so I have a 3 fields in a webBrowser that my bot will need to fill. 1st field is the City: 2nd is the Place Name: 3rd is the Street Address: Here is an example of my addresses:
~1Cafe~2 ~322 Queen st.~4 ~5Toronto~6 So for the city I will need to fill it with all the text in between ~5 and ~6. Right now this is what I have
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Question is: How to test for null value of a field in an ADO recordset.Using Visual Studio 2010 Ultimate - VB.NET
ADO Connection to ODBC database
I am working with a table that contains about 10,000 records of which I need to do additional processing on about 1500. The records I need to process are qualified by the field'Cataloged' = True. The problem I have is the table allows for True, False or Null values (I have no direct control of the table to change from allowing Null) for the field I need to test.I run into errors when the value of the field is Null and need to figure out how to determine its Null state prior to trying to qualify the field as True or False value to prevent the errors.