If you have been reading my posts I'm trying to learn this ADO.net code. So I have been reading and coding and I have a Question. How to I know in .net, if the record exists to make the decision to Add New Row or UpdateRow? Here is the code from the web I have been working with to better understand this, I could use some help on the decision making code needed to Update or New row.
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I have a small database. 2 main tables called CaseDetails and Checks.Each record in CaseDetails can have 3 checks recorded against it in the Checks table. But can only have one check of each type (check types 1, 2, 3).I have 3 linkbuttons which will take the user to the input form for each 'check'. If a 'check' already exists i want to hide the linkbutton that takes the user to that 'check type' input form (the 3 input forms have different fields).So what i need to do, is connect to the SQL database and see if a record exists for each 'check type' and hide the linkbutton to prevent users from entering another record with the same 'check type'?I have tried reading the reults into an array and examining that array, but havent been able to do so.
View 5 RepliesI have a tenant details form that has a field called TenantID, I also have a Lease table that also has a TenantID field, what I want to do is click the lease button, check to see if the lease already exists, if it does open the lease form to that record. If not then open the lease form to a New record so the user can enter all the information for that lease.
I am trying to use the below code but am having a little trouble understanding how it all works. What needs to be declared, what doesnt
HTML
Private Sub btnLease_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLease.Click
Dim fm2 As New LeaseDetails
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Working on an VB/ASP website in Visual Studio 2008. Getting the error "You cannot add or change a record because a related record is required in table 'abc'
It is true that table xyz (the target of the INSERT) is in a parent-child relationship with table abc. The PK in abc is a column RequestID_lng. The FK column in xyz is also named RequestID_lng
This is the only relationship these 2 tables are in.
I am trying to add a row in xyz with a value of 45 in the FK. There is already, previous to this action, a row in table abc with a value of 45 in the PK. So the parent already exists for this child.
I have used the watch window to copy my SQL code for the INSERT query that is being executed. I pasted that code into a new query in the Access DB and executed it without problem - it actually added the row that .Net should have.[code]...
I am having a ton of trouble trying to check if a record exists. I continue to get a data mismatch on my command.ExecuteScalar().
Code:
Protected Sub btnRegister_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnRegister.Click
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I am importing alot of data from a text file into an access database with the code below. (From a Comma delimited text file) The problem is that I do not want to import duplicate records. I have the "IDNr" column in my access database set to "not allow duplicates" and need my code to check if there is already a record in the database before trying to import the data. Otherwise it will just give me an error or not import the rest of the data. I could do to make sure that there are no duplicates for the IDNr column?
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I am using VS 2008 and MySQL. Which one of the following methods is efficient or a proper one to check if record exists or not before making an attempt to insert.
1. HasRows Property.
2. Select Where Exists
3. Select Count(*)
Or if there is any other appropriate method ( which i am not aware of ) available to do it in vb.net ?
At the moment when a user logs into my system it checks to see if a job exists, if so the records are put into a datagridview. However, if there are no jobs in the database I get an error.
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i can't find any wrong, if record exists then updated the record but only can insert the new record.
cannot updated the record.why?
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I have an default.aspx page that I'm trying to have redirect the user to a different page depending on whether or not their deviceId is stored in the SQL Server database. It should direct the user to the login.aspx if the record for the user is found or to the newdevice.aspx page if there was no record found. I want this to occur on Page_Load but have not been able to figure it out so far.
View 3 Repliesthe next code is working but when I try to insert an existing record, it gives me an error and I want to add a msgbox to let people now that the username is already taken.Only the username cannot repeat on the database because it's the primary key.. the rest of the table rows can repeat.
Dim cn As New OleDbConnection
cn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Users\Fabio\Desktop\Telemoveis\Telemoveis\Db_Tel.accdb"
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I'm updating an app for children I wrote in VB6 to VB2010. It uses a rather extensive MSAccess Database. It works perfectly but I need to update it to utilize better speech technology. I have read a lot about SQL and can't find how it is useful for anything accept business applications that add, delete or update records as long as you hard code in a name. I don't use datagrids and I never display a table. how to do a few things, I can figure the rest out.
In VB6, I had:
Option Explicit
Public db As Database
Public rs As Recordset
Public Reader As Recordset
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Cant get the following program to display the decision in the listbox. (visual basic 2005 Express edition)
Public Class Form1
Dim pupil As Integer
Dim number_of_pupils As Integer
Dim pupilname(4) As String
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i doing my project in ID3 decision tree algorithm.so i urgently need it.plz send me to mail id {REMOVED}
View 1 RepliesHow can I make sure a file exists on my Desktop?
I use this code but It doesn't work ...
MessageBox.Show(IO.File.Exists("DesktopFolder" & "Myfile.lnk").ToString())
In the developing environment the computers do not have com ports, but I am working on a project for a client who does. It is annoying that when I test the program on my computers I always get the error. "The port (COM1) does not exist"
I am catching the general exeption but the debugger stops there anyway. I can press "continue" and the program resumes but I would like to clean that up and not try to open the port if the computer does not have one.
vb.net
Try
SerialPort1.Open()
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lblNoCOM1 just tells the user that there is no serial port and that the barcode scanner is not working.
I've made an interface called ApprovalEvent in a separate file with the namespace myproject... I've also made a class called PurchaseOrder... it's also in the same namespace, just in a separate file. Whenever I try to make PurchaseOrder implement ApprovalEvent it always says that ApprovalEvent is undefined...
How can I make the class recognize that the interface exists but is in a different file?[code]...
I want the user to be able to click on the "search" button, and for a diaglog box to open, with two options. "ID" or "Postcode".
How would i do this, and then how could i intergrate my line of code into that?
I hav a web service which pull records from a database and I am hosting these services in IIS which works fine but I am trying to retrieve the record and display the record in a listbox displaying the time field as the text for that record.I have created the following function
public sub get_data()
dim dt as new data.dataTable
dim service as ws webservice.webservice
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I am using visual basic 10 to make simple application that print and make invoice iam all most done but is there any way to keep a record of invoice maked by a referance number and when user want to see the record, he or she just enter the reference number and he got the printed or maked invoice.
View 1 RepliesI am trying to check a record in database before inerting a new record here is my code but problem is when i enter a names first alphabet it imediatly populate massage. i want to check it after entering whole name
Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
Try
Dim cnString As String = "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" &
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I am trying to make a record counter for a textbox i have on my form. Basically i have an Access database called Member and wish too count how many records there are in the database and insert the figure into the textbox called MemberID. I am doing this to stop duplication in my form. I am doing it on the MemberID which is a Primary Key and not an autonumber
vb.net
Public Class frmMember
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I was about to make an error message when there is no record both pat_brgyno and pat_famno in the database. I don't know how to make it. What my logic says is something like this:
mtb=maskedtextbox
if mtbbrgyno.text<>pat_brgy and mtbfamno.text<>pat_famno then
msgbox("No Record"
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i have use below code to make sure the listview only contain 3 record n if more than 3 records to prompt error message and disable the NEXT TRANSACTION button. it works well. But the problem is when i delete 1 record out of 3 it suppose enable the NEXT TRANSACTION button but the button is still disable. whats wrong with my code.
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I want to know how can I get specific record to make report? For example I have student information there in my program. Its easy to create a report of all students. but if user wants to get & print specific record of a student what should I do? I have another question to ask. I have heard it that its possible to show each specific record there in each page by using NewPageAfter or NewPageBefore. I need to know is there any way that user will select ID number from combo box & when he will click on report button it will create report of that student what has been selected from the combo box?
View 1 Repliesi need a update statement to make a record = 1 example : the colum what need to change is active and it must stand on 1 to show you in to a listview (that part works) but i need to do it manualy to make them active now i liked to when the login is a succes then the record = 1 for you this is my code :
Private Sub Button1_Click_1(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim adapt As MySqlDataAdapter
Dim sqlquer = ""
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i get this error : Object reference not set to an instance of an object.
How can I make a program to record sound from the microphone? I've tried lots of thing but they don't work. Can someone show me how to do ths using winmm.dll or DIrectx?
View 4 RepliesI am just new here, i just want to ask if there are any of you who knows on how to determine if the record is flag or deleted in a dbf file. I am trying to make a program which can determine if the record is deleted or flag.
View 11 RepliesI have made an app which has id and name and class and tel fields using sql2005 database I made ID field as primery key so when i delete record from table it doesnt rearange it self for example I added record number
1
2
3
4
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Iam using sql2005 database in vb.net2005
my table's name = tab1
I have 3 fields
1- ID = auto number =primery key
2- IDD = number
3- name = text
now if I add 10 names in the table from (1-10) =1,2,3,4,5,6,7,8,9 ,10
then if I delete name number 6 the IDD field will rearrange it self from( 1-9)=1,2,3,4,5,6,7,8,9 instead of 1,2,3,4,5,7,8,9,10