VB Expression For Finding Null Value In DataRow Field

Jan 29, 2010

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.

View 3 Replies


ADVERTISEMENT

DataRow Not Produced Via DataAdapter.Fill If A Field Is Null?

Apr 20, 2012

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( _

[Code]....

View 14 Replies

Null DateTime Value In DataRow?

Jul 15, 2011

I 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.

View 5 Replies

Check If A Field In A Data Table Is Null Before Creating A Textbox Bound To That Field?

Feb 24, 2010

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 Replies

Update ADO.Net DataRow Column To Null?

Dec 7, 2009

Using 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?

[Code]...

View 3 Replies

Update A Field In Each Datarow?

Sep 11, 2009

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]...

View 26 Replies

Handling DataRow Input String Was Not In A Correct Format For A Null Value?

Sep 30, 2011

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 Replies

C# - Finding A String Expression In An Sentence?

Mar 17, 2011

I have like a three word expression: "Shut The Door" and I want to find it in a sentence. Since They are kind of separated by space?

View 6 Replies

.net - SSRS Report Expression - Null Being Treated Like Zero?

Apr 11, 2012

Consider this SSRS value expression :=IIF(First(Fields!MyCol.Value, "MyDataSet")=0, "yes", "no")

MyCol is a Nullable column. I want "yes" to be output only when MyCol equals 0. The code above correctly evaluates to "yes" when MyCol is 0. However, it also evaluates to "yes" when MyCol is Nothing (i.e. NULL in SQL Server). Is this expected behavior ?

I had to resort to the following longer expression to get the desired result :

=IIF(Not(First(Fields!MyCol.Value, "MyDataSet") is Nothing) And First(Fields!MyCol.Value, "MyDataSet")=0, "yes", "no")Is there a shorter version of this which also works ?

View 1 Replies

Linq Expression Returning Null Rather Than Empty Set

Nov 18, 2010

I am finding this weird issue. When I do this > activities.Where(Function(a) (Not a.IsDeleted And a.ParentId = 100) It returns an in-memory query & when I try opening it up, it throws a object not set exception. This only happens when there were no items which satisfied the condition. Shouldn't it be returning an empty set? When there are items satisfying the condition, then it returns a list & works all good.

View 1 Replies

Error When Field Is NULL

May 2, 2010

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

View 1 Replies

Remove Row In CSV Where Field In Row Is Null?

Nov 1, 2010

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 Replies

Set Date Field To Null Value?

Dec 12, 2011

I 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 Replies

The Value Expression For The Text Box 'textbox1' Refers To The Field 'name'

May 15, 2012

this is the errors when i try to compile my created report in vb2010: the value expression for the text box 'textbox1' refers to the field 'name'. report item expressions can only refer to fields within the current datase scope or, if inside an aggregate, the specified dataset scope. this is my dataset:

[Code]...

View 2 Replies

Test For Null Value Of A Field In An ADO Recordset?

Oct 24, 2010

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.

View 4 Replies

.net - Checking For Null In Date Field?

Oct 25, 2011

I have an ASP.NET application that crashes when a null date value is returned.

The code line is:

excelWorksheet.Cells("A" & xlRowCounter).Value = IIf(IsDBNull(dRow("sysdate")), "", Format(dRow("sysdate"), "MM/dd/yyyy"))

Error message:

ERROR: System.ArgumentException: Argument 'Expression' is not a valid value.

How would I check for a null date, and replace it with "" in my app ?

View 4 Replies

Dealing With A Null In A Varbinary Field

Aug 3, 2009

I'm trying to test a varbinary(max) field to see if it's null. I'm trying to figure out if it's a null or not in the select statement, hoping to avoid having to do this locally for every row of the returned dataset. This is the SQL I'm using,

[Code]....

View 1 Replies

Display Null Value From SQL Image Field?

Dec 30, 2009

I use following codes to display image from sql server. [code]...

View 3 Replies

Have A Field In A Datatable (dt) That Can Be Integer Or NULL?

Mar 1, 2010

I have a field in a datatable (dt) that can be integer or NULL.

View 7 Replies

Insert Null Value In Date Field?

Nov 22, 2010

i have a maskedtextbox which will accept only date in the format of "DD-MM-yyyy" no i want to insert this date in my db. i have done this successfully.

Now i want to insert null value in through that maskedtextbox .

View 6 Replies

Setting First Field In A Combo Box To Null?

Oct 1, 2011

I have a databound ComboBox on my form. Is there any way that I can make the first field blank.

I can do this with a DropDownList in the HTML part of .Net but is there a way to do it for a ComboBox?

View 2 Replies

SQL Record Search But Field Is Sometimes NULL?

Mar 2, 2010

I am trying to do a SQL query to see if an Address already exists in my database. My addresses are structure like this:

line1
line2
line3
city
state
zipcode
country

Sometimes line2 and line3 are NULL values in my database.I am using .NET TableAdapter and DataTable to make my query. When I try to pass in my line2 parameter (@line2) it is equal to a string with value = nothing. My database does not interpret this as NULL and says the records don't match, but I know they do? How do I pass in a string = nothing and have it compare to a NULL value in the database as being equal? I have tried string = DBNULL.value but won't compile.I have done similar comparisons with integers etc. using integer = Nullable (of integer) but this does not exist for strings.

View 3 Replies

VS 2008 Put Null Value In A Field Number

May 15, 2009

I have in my DB a few number fields, but I would like put null values or empty values in some of this fields...

I had try this but without results:

If valorcolocardebito = 0 Then
valorcolocardebito = Nothing
End If

[Code].....

View 3 Replies

Getting Null Value Of Hidden Field At Server-side

Feb 18, 2011

I am calling a Java-script function, in that i am passing the value of hidden field, that hidden field i want to use at server-side, but the value of hidden field is null.[code]...

View 1 Replies

Insert Null Value From A Textbox At Numeric Field?

May 17, 2012

Why when I try to save a null value from textbox at sql server 0 is saved?

View 2 Replies

Made Empty Or Null Field In Datagridview

Nov 15, 2009

I key-in data from textbox to datagridvie..........the date data the format datatable is:

[Code]...

View 1 Replies

Select All Records Where A Field Is Null Using LINQ?

Jan 25, 2012

I've got a table that caches calculated values for certain dates. I want to use LINQ to select all rows where the calculated value fields are null.But when I use isNothing I get an error that LINQ can't translate this into T-SQL. Is there a way to select null values with link, like this...?

Dim var = From rec As Record In myDataContext.Records Where IsNothing(rec.calculatedValue) Select rec

Other posts on stackoverflow mostly discuss how to avoid or check for null values with LINQ.

Note: I can't just set cacluatedValue's default to -1 to flag records whose calculated value has not been set (and then select those records) because I run queries that sum/average the calculated values. Selecting nulls seems cleaner and less bug-prone.

View 1 Replies

Setting Date Field To Null With DataTables?

Mar 31, 2010

Im writing an app which connects to a SQL Server database, via datasources / datatable.When Im looking at my .xsd I can see DataTables containing DataColumns. Each DataColumn has a 'NullValue' property which defaults to '(Throw exception)'.Because I have nulls in my tables I have gone through the fields and set all System.String fields to NullValue = 'Empty', System.int32 field to NullValue = 0.

View 1 Replies

.net - Pass An Expression To Act On A Single Field In An Anonymous Type In LINQ?

Mar 27, 2012

I have the following Data Transfer Objects defined:

Public Class MemberWithAddressesDTO
Public Property Member_PK As Integer
Public Property Firstname As String
Public Property DefaultAddress As AddressDTO
Public Property Addresses As IQueryable(Of AddressDTO)
End Class

[Code]...

View 1 Replies

Cannot Leave Field Null When Running Insert Statement

Jun 8, 2009

I have the following query that I use to create a new record in a database. If I leave any field on the form blank, for example, it throws the error "Memo.Lastname" cannot be a zero length string. Other than that the query executes appropriately.
Private Sub cmdSaveMemo_Click(ByVal sender As System.Object,
ByVal e As System.EventArgs) Handles cmdSaveMemo.Click
If Len(Me.txtMemoID.Text) <> 0 Then
Memo.SaveMemo
[Code] .....

View 2 Replies







Copyrights 2005-15 www.BigResource.com, All rights reserved