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 RepliesAssuming rnameTxt is a textbox and is bound to a field is a DataSet named "TableData".
rnameTxt.DataBindings.Add(New Binding("Text", TableData, "Customer.rname", True))
I have a date time picker bould to a Nullable Datetime field in a sql server datatable. The ShowCheckBox option is set to true. If the user unchecks the checkbox on the datetimepicker I would like to the field to be set back to null in the DataTable. The default behaveour does not seem to do this and there is no specific event for the uncheck.
Private Sub dtpCertDate_ValueChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles dtpCertDate.ValueChanged
If dtpCertDate.Focused Then
[code].....
How to check if string entered in a text box matches a field in a data table
I have a form with two text boxes for users to enter their Username and Password. When they enter their details and click the 'Login' button I want their details to be
checked against data in a data table to see if they match or not. I am using an 'if...else' statement but can't work out the syntax to use. My code is as follows[code]...Check when string entered in a text box matches field in data table?
How to check if string entered in a text box matches a field in a data table.I have a form with two text boxes for users to enter their Username and Password. When they enter their details and click the 'Login' button I want their details to be checked against data in a data table to see if they match or not. I am using an 'if...else' statement but can't work out the syntax to use. My code is as follows:[code]The fields I want to match the textbox strings against in my database table are called 'Username' and 'Password'.
View 2 RepliesLets say I have a form with several Textboxes that are all bound to "bindingsource1". I'd like to be able to check the field data type each textbox is bound to. Something like this,
Dim ctl As Control
For Each ctl In frm.Controls
If ctl.GetType.IsAssignableFrom(GetType(TextBox)) Then
[Code]....
Why when I try to save a null value from textbox at sql server 0 is saved?
View 2 RepliesI am creating a database in VB.NET for a movie rental place. I currently have three forms;
Member Information
DVD Information
Borrow DVDs
What I would like to do is when I am viewing a member's details, if I click a button 'Borrow DVD for Member', the member's ID number transfers over to the Borrow DVDs table in the Member ID which also would hold some information from the DVD Information table, but I'm sure if i can figure out how to do this firstly, I will be able to apply the same rule and work it out myself.I have been trying to use a query statement like;
INSERT INTO [Borrow DVDs].[Member ID] [IN goodstuffvideos.mdb]
SELECT [Member Information].[Member ID]
FROM [Member Information]
but that has been coming up with error codes and completely not working.
Borrow DVDs table fields are: Borrow ID, Member ID, DVD ID Number, Hiring Fee, Borrowing Limit?
DVD Information table fields are: DVD ID Number, Title, Rating, Hiring Fee, Borrowing Limit Member?
Information table fields are: Member ID, Family Name, Given Name, Address, Town/Suburb, Postcode?
The error coming up is; Error in INSERT statement. Unable to parse query text.And under that it says The query cannot be represented graphically in the Diagram and Criteria Pane.
I've been working on this for some time and I'm surprised that no one else has had this problem. I have a databound form with multiple date fields. I cannot delete a date field once it has been populated. I can change the date, but that is about it. Once Clearing the field i cannot lose focus of the textbox or even close the form. I have read one article on this but it does not seem to be working. The below code I have found. how to get the field to allow nulls? This is not an issue with the table not allowing nulls either.
[Code]...
Is it possible to check a MS Access database table with existing entries to see if one of the fields is empty.[code]....
View 4 RepliesI'm using visual basic to code a program to help with weights and center of balance on aircrafts, as I'm my unit's new air load planner. The math isn't hard to do, it's just that much of it is trial and error, and redoing all the arithmetic over and over again until the aircraft's C/B is in acceptable limits can eat some time up. So, since i'm trying to learn programming I thought this might be a good way to use it for a real-world scenario.
[Code]...
I have a table and I want to select a field in it and then display it in a text box
something like:
SELECT userName
FROM userTable
WHERE (userLogged = 'ON')
how can I display the selected username in a textbox?
BTW the userLogged indicates wether the user is logged in or not
if the user is logged in then the userLogged will be changed to "ON"
if the user is not logged in it will be "OFF"
I know it's not that practical but I'm still practicing.
I'm using Visual Web Developer 2008 Express I use table adapter procedures for querying
I currently have this working already for one of my combo box's, but when i try to use the same code i get this error ''There is no row at position 6.'' . The are 2 fields in the table asset_type_id, asset_type_name', im trying to dispaly the values in a combo box for the field 'asset_type_name.
the code for ' Friend Sub RetrieveCustomerInformation2()' works but the other friend sub throws the error.
Imports System.Data.SqlClient
Imports System.Data
Imports System
Imports System.Data.OleDb
[Code]...
First I have 2 tables, for example Customer and Orders, and in the database there is a foreign key relation between both. For clarity Orders have a foreign key field to the primary key of Customers, thus Customer is the parent and Orders is the child table of the relation. My application is a Windows Form application, and I add a dataset to the project, in which I drop the 2 tables, and the relations between the 2 tables is automatic added. Now I will om a form loop through the Orders table (witch is the Child table) and show in a textbox some fields of the Orders table and also the Name field of the related record of the customers table. Regarding binding a textbox fo a Orders field I do it this way,
Dim myDs As New DataSet1
Dim myAdpCustomer As New DataSet1TableAdapters.CustomerTableAdapter
Dim myAdpOrders As New DataSet1TableAdapters.OrdersTableAdapter
myAdpCustomer.Fill(myDs.Customers)
myAdpOrders.Fill(myDs.Orders)
Dim myBindingSource As New BindingSource
myBindingSource.DataSource = myDs.Orders
myBindingNavigator.BindingSource = myBindingSource
TextBox1.DataBindings.Add("Text", myBindingSource, myDs.Orders.OrderIDColumn.ColumnName)
But now I can't find how to bind a textbox to a field of the Customers table witch is the Parent table of the relation.
I'm using VS2010 and SQLServer 2008. I'm trying to test for DBNull in datafields, but every formulation of a test I have imagined (or found) throws an error. Specifically,"The value for column 'ColumnName' in table 'TableName' is DBNull." (system.data.strongTypingException).Well, not too helpful. I know it's DBNull, and I want VB to recognize this.Here is what I've tried so far (all with the same result).
[code]...
How can I call my TextBox ID = "txtFromAddress" data to a table that I am trying to send? Right now it is just showing the text '& txtFromAddress' on the table on the email that I send.
[Code]...
How can use vb.net forms to add or delete quantity in a field og ms sql data table.. EG: like in stock, we hv to add purchased stock and deduct selled stock.
View 3 RepliesI could connect to the database alright. My problem is how to retrieve data into text boxes. In Vb 6.0 i could use the ADODC control to retrieve onto the textboxes as follows[code]...
View 1 RepliesI am trying to bind data from a text box on my form to a field in my database table. First of all I have created a DataSet, BindingSource and Table Adapter in the forms Design view, but I am having from there. Under the properties of each text box I have set the DataBindings (Text) to the field in the table under the forms instance and DataSet rather than the Projects Data Sources. I am very rusty at Visual Studio 2005 and that is all I have to work with.
View 2 RepliesWhat is going on with my code. To .NET and handling SQL connections. I am trying to catch an error where lets say someone puts in something that violates the rules of the field (i.e. they put data in a field that doesn't matched what is on the other table.) Please find teh code I ahve put on the save button to try to catch the error. Instead of popping a message box up the program just closes itself.
Private Sub Job_tableBindingNavigatorSaveItem_Click_2(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Job_tableBindingNavigatorSaveItem.Click
Try
[CODE]...
Im pretty use to doing loops (although still relative new to vb) in my code however am having difficulty setting up one that picks up an entry in one data table and then sums a field in another where records have matching criteria. Example:
[Code]...
What i am trying to do is set up a datagridview on a form that shows the summary data. The time is controlled on the form by a trackbar (output to textbox) and I started setting up a loop using (For/Next) to isolate firstly the matching entries in field 3 (time). This works fine. I then used compute to sum the the field 2. However what i want to do is to loop through table 2 and where entries match i.e. where Field 1 in table 2="A" sum matching entries in table 1 where the DateTime matches.
I'm trying to format a datetime field to just show the date. The datetime is bound to an asp:label and for the Text attribute I have tried the following....
Text= String.Format("{0:D}", '<%# Bind("CReviewDate") %>')
and
Text= String.Format("{0:D}", <%# Bind("CReviewDate") %>)
[code]....
In all cases I get a green wavy line under the equation and the tip help says "Validation (ASP.Net): If this attribute value is enclosed in quotation marks, the quotation marks must match.
String.Format("{0:D}", DateTime.Now)
is the syntax that I have been told should work.
I'm trying to populate a date from a bound text field in a DetailsView. I keep getting a error when a DBNull is in the column. How do I avoid the DBNull when populating the text field.
My code is as follows:
<asp:TemplateField HeaderText="CBYD Clear Date">
<EditItemTemplate>
<asp:TextBox ID="CBYDExpDate" runat="server" ReadOnly="true" Text='<%# IIf(Eval("CBYDDate") is DBNull.Value,"", String.Format("{0:MM/dd/yyyy}", Eval("CBYDDate").AddDays(30)))%>' />
</EditItemTemplate> </asp:TemplateField>
On my form i use binding source bound to fields.. if a user starts to change something then hits cancel (i set all the fields to "" to clear them) and then if they choose that record again it shows nothing in the bound fields..
is there a way to reset/cancel from editing without loosing original values?
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 RepliesI have a textbox, a sql database, a binding source bound to the sql database. I can use auto-complete mode of the textbox with custom strings and it suggests in in a drop down form as the user types in a textbox. How can I use autocomplete mode with datasaved in different records of a field using the bindingsource?
View 5 RepliesI have a custom control with a bindable property:-
Private _Value As Object
<Bindable(True), ... > _
Public Property Value() As Object
Get
[code]....
Also, here, I'm adding a handler to the DataBindings.CollectionChanged event.This is the second place that I retrieve the type:-
Private Sub DataBindings_CollectionChanged(ByVal sender As Object, ByVal e As System.ComponentModel.CollectionChangeEventArgs)
If e.Action = CollectionChangeAction.Add Then
Dim b As Binding = DirectCast(e.Element, Binding)
[code]....
I need the first place, because the BindingContextChanged event is not fired until some time after InitializeComponent.The second place is needed if the binding field is programatically changed.Am I handling the correct events here, or is there a cleaner way to do it?
Note: My GetValueType method uses the CurrencyManager.GetItemProperties....etc, to retrieve the type.
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.