Add Null In Access Database?
Feb 10, 2010I want to add a null binary field in Database.[code]...
View 2 RepliesI want to add a null binary field in Database.[code]...
View 2 RepliesConsidering that Grade.firstExam, Grade.secondExam, and Grade.finalExam are all TEXT and not numbers, i can't get the exact solution to convert null values into Zeros. I already tried to use NZ() but it returns an error message (Undefined Function 'NZ' in expression)im using VB.net with MS Access as my database. i also imported System.Data.OleDb Namespace.
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How can i convert empty string or null that exist in the field?
I am trying to utilize the access database, but I'm getting an error message: Value cannot be null. Parameter name: dataSet
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That's the code I'm using, why I'm getting this error?
How update the Access database in VB.Net with NULL values using OLE DB command
View 2 Repliesi am working in windows appl vb.net 08. And i am working in Access DataBase.I have one Table Called "Person" . In this "Person" Table one Column Name Called "OtherName". In this Column binded in one of the Combobox in a Form.But the Problem is "OtherName" Column having the Null Values.Before i bind this Column to Combobox i want to convert this NULL Values to String. Why i need the values in STRING means , In my code i using this Combobox as a filter in SQL Query.If i didn`t change the Null Value to STRING , The Combobox SelectedText or SelectedValue is Showing Nothing. So i am not able to get the Record.
Whn i write a Sql Query to Combobox and apply filter in WHERE statement like Combobox.Selectedtext or Combobox.SelectedValue In "Selected Change Committed Event" then i should get the record in the Output right but unfortunatly i am not getting the Record. The Record Count in DebugPrint showing 0.
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Ive created one database Sql Server Compact Edition 2005, with one table ("Cliente") I know that I can created my database good, but i have a problem saving information since three textbox, in my table(With columns "Nombre" "Apellido" "Cliente". In my form there is a button save ("Guardar"). When I do click in my button appear the next message : "The column cannot contain null values. [ Column name = Nombre,Table name = Cliente ] " and happen the same with apellido and Id_Cliente. And this happen becouse my code cant save the information....
This is the code
Option Explicit On
Option Strict On
Imports System
Imports System.IO
Imports System.Data
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And the code for my button is:
Private Sub cmdguardar_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles cmdguardar.Click
Dim myconnection As SqlCeConnection
Dim mycommand As SqlCeCommand
[CODE]...
I can save my data to access database and in the access database field I set it to date/time.But problem is when I get the value out from the database.. the format is always month/day/year hour:minutes:seconds example today: 5/2/2011 12:00:00..How to get the value into listview becoming May/2/2011 without the hour..Here's my code to get it from database ListView1.Items(i).SubItems.Add(dt.Rows(i)(14).ToString).The second problem is.When I would like to edit, how can the datetimepicker get the listview value ? [code] info: using access 2003 (.mdb) the Date of Birth field has been set into Date/Time.
View 2 RepliesDeveloping a simple app in vbe 2010. Suddenly I have a (fatal?) warning ("Value cannot be null. Parameter name: object Type") and can no longer access the form. Problem seems to have started when I laid a timer down. Have since commented out the timer sub and call, but the warning persists. I can, strangely, run the app in debug. Have carefully inspected the all code and came fine no error.
View 3 RepliesI have an application that has an Ms Access 2007 DataBase which runns great if access is installed. Is there any code that I can use in vb that I would be able to run access with out installing it.
View 5 RepliesI have tried to import an Access Request in Excel. However, the last field (SP) contains Null cells and it seems that it prevents the importation in Excel. There is a way to change Null cells?
Sub Creating_Universe()
Dim connFI As ADODB.Connection
Dim rs As ADODB.Recordset
[Code]....
I have a couple of textfields in a Windows form. One of these textfields is allowed to be NULL. When I enter a value for every field, it is all inserted, no problem. When I leave the field (txtGewicht) blank, I can't seem to be able to insert NULL in Access Database.
If Double.TryParse(txtGewicht.Text, 0) Then
klant.Gewicht = Double.Parse(txtGewicht.Text)
Else
[Code]....
This is what I get:
"Cannot set column 'Gewicht' to NULL, please use DBNull instead"
So I changed 'Nothing' to DBNull.value, but it then tells me that System.DBNull cannot be converted to type Double.
I have a button 'start quiz' which uses the dataset to fill the quiz form - ready for the user to start answering the questions.However, I am getting a 'null reference' at the point where the 'navigate records' on the quiz form is called. Have looked up that it means I have a variable that is null. But I have declared all the variables etc. Not sure what I'm doing wrong. I am very new to programming and I have spent quite a bit of time on this already.This is the code for the student user login:
Private Sub btnLoginStudent_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoginStudent.Click
FrmQuiz.Show()
[code].....
Did anyone knows where can I upload a folder so my programe to be able to download an update from there???
View 3 RepliesI have two Access database, say database One.mdb and Two.mdb. I want to use VB2005 to export tblCustomer from One.mdb to Two.mdb, and replace the existing tblCustomer in Two.mdb, during run time. I basically want to simulate the export function that is available in MS Access (which can export one table from one Access database to another) with VB2005 during run time. I can think of a way by querying the table to a dataset and then delete everything on the other database before filling the table in that database with the dataset
View 1 RepliesI am trying to import data from an access database to a access database that my project uses I am having problems with combo box fields in the database with the data. I want to import what is displayed instead of the numerical key value. Example: The combo box displays employee names but the value stored is the key value from the employee table so instead of importing John Doe it imports 2 is there a way to make the actual name instead of the number?
View 4 RepliesI have a select statement which was returning the required values but when I changed the OS date from English(US) to English(UK), it now returns null. I believe the problem is concerned with date since in the query am selecting values where the date from the database is the same as the date in a combobox but I don't know what else I can do. It almost looks like the dates in the combox and in the database are not the same and yet the date in the combobox is actually retrieved from the database and has been returning values fine until I changed the system date format.Here's my select command:
cmd4.CommandText = _
"SELECT sum(brought_qtty), recieved_qtty from brought_coffee, centre_weigh where brought_date=#" & _
dtComb.Text.Trim & "#" & _[code].......
i have a combobox which get value from database through dataset. when i run the program n click on the combobox, the value is auto fill in with data from database. is there anyway to add a blank entries to the selection on the combobox??
View 5 RepliesI know I'm being an idiot here and I just can't work it out. But i'm trying to take some data back from a vb.net database. It's falling over with a Object reference not set to an instance of an object error. And before the code runs it's saying the variable is being used before it's set, but I can't see how. Code:
Private taNotifications As dsDataTableAdapters.NotificationsTableAdapter = New dsDataTableAdapters.NotificationsTableAdapter
Dim notification As dsData.NotificationsDataTable = taNotifications.GetDataByClientID(userrow.UserID)
If notification.Rows.Count > 0 Then
Dim notificationrow As dsData.NotificationsRow
Dim forwardURL As String = notificationrow.ForwardLocation
End If
It falls over on the Dim forwardURL As String = notificationrow.ForwardLocation
Is their a more elegant way to assign a space to a value, if a database call returns null for a data set column? I am doing the following check which is pretty tedious:
If (ds.Tables("employee").Rows(0).Item("txtNamePrefix").IsDBNull(0)) Then
txtNamePrefix.Text = ""
Else
txtNamePrefix.Text = ds.Tables("employee").Rows(0).Item("txtNamePrefix")
End If
When the SQL Server 2005 Wizard is used to create a database project, the following error is issued[code]...
View 3 Repliesi have a checkbox in gridview.
<asp:CheckBox ID="chkStatus"
runat="server"
Checked='<%#GetStatus(Eval("VaccinationCompletedStatus"))
[code].....
I am working asp.net vb application. I have set of values to be inserted to Database.But their some fields are optional to be filled. I need to check the textbox empty. If empty I should not enter the value to Database. How to work on this?
View 4 RepliesI need to scan database and insert its values into an array. But I'm having some difficulties in handling null values and array.
The database looks like this:
0 1 2 3 4
30 31 32
33 34
36 37 38 39 40
38 39 47 48
I want to make array rr_item which gonna looks like this:
arr_item(1)={0,1,2,3,4}
arr_item(2)={30,31,32}
arr_item(3)={33,34}
arr_item(4)={36,37,38,39,40}
arr_item(5)={38,39,47,48}
Every code I've tried result in error everytime I tried to insert null value into any kind of c=variable, including array which I want to use. And I'm not quite sure with what I'm doing in jagged array I want to build.
sql_list = "SELECT * FROM retail"
oledbCnn = New OleDbConnection(connetionString)
Try
oledbCnn.Open()
[Code] .....
I'm trying to save a TimeSpan variable from VB into a SQL database, into a non-null column.It works fine for other values, but when I try to save 00:00:00 I am told that I cannot save NULL into a non-null column...Is there a way to get it to actually save this rather than think that it's NULL?
Note: This code is a method in a class, which has a property:
Private mCommand As New SqlCommand
Dim Param As New SqlParameter
Param.ParameterName = "@" + ParameterName[code]......
My application has textboxes that are bound to DataSet fields of a SQl Server 2005 database. The columns in the database allow nulls. The column properties in the DataSet have AllowDBNull set to true. Attempting to write the un-changed data back to the database replaces the NULL values with "", and the update fails on the datetime columns with an error about being unable to convert "" to a date. It appears that the problem is that the null values from the database are being converted into empty strings when the textbox is populated.
View 4 RepliesI have run into this problem a few times and have never come up with a good answer. I figure others must have dealt with this already.I have a datareader returned from the database and I want to use the values therein however values may or may not contain NULL. I would like to have a unction that takes in the value from the datareader and returns the value if it is not NULL and blank space if it is NULL.The problem I have is that the data-type of the variable I am testing is variable. It can be a String, and Integer or a DateTime. Can anyone suggest a simple way to test the value and then return the original value (as same data-type if possible) or something else if it is NULL
View 5 RepliesI am looping thorugh a datatable and and printing each row to the console and I keep on getting a dbnull error. I inserted an if statement in my loop to try and catch it, but I can't seem to get it to work.
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How to set database to null if datetimepicker.check is false?what is the code other than empy string ""?[code]...
View 4 RepliesHow can I change the following code to write to the database null instead of empty strings?
Public Sub SetChangeRequest(ByVal referenceLeaseID As Integer, _
ByVal referenceCustomerID As Integer, _
Optional ByVal custUnitNum As Object = Nothing, _
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am trying to write to a database via a stored procedure. I am trying to save my values to an object and then write to the database. When I click the button to save the record I am getting a null reference.The below is from the frmDMR class.
Public Class frmDMR
Private m_dmrissue As DMRData
Public Property NewDmrIssue() As DMRData
[code]....