Database - Fetching Data Between Primary And Foreign Key?
Feb 3, 2012
How do I fetch the loginID and display the student data on the textbox?E.g. I login with loginID of 18 but it only display the data of 12
Private Sub frmLibrary_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'LibraryDataSet.Student' table. You can move, or remove it, as needed.
Me.StudentTableAdapter.Fill(Me.LibraryDataSet.Student)
End Sub
View 1 Replies
ADVERTISEMENT
Oct 5, 2011
Is it possible to have a Foreign Key as the Primary Key?
<Key()>
Public Property AssignmentID() As Integer
<ForeignKey("AssignmentID")>
Public Overridable Property Assignment As Assignment
Public Overridable Property User As User
For the code above I get an error:One or more validation errors were detected during model generation:System.Data.Edm.EdmAssociationEnd: : Multiplicity is not valid in Role 'AssignmentLocks_Assignment_Source' in relationship 'AssignmentLocks_Assignment'. Because the Dependent Role refers to the key properties, the upper bound of the multiplicity of the Dependent Role must be �1�.
I'm trying to create a table which has one (or none) record per assignment.
View 3 Replies
Jan 23, 2011
I'm having some major issues trying to figure out What's going wrong with my code.
The general problem is that I can't get the foreign key in one of my child tables to populate the primary key from the parent table. I have a parent table named "ISSUES" and a child table named "ISSDESC". The primary key for ISSUES is ISS_ID which is an autonumber. The foreign key is ISS_ID in the ISSDESC table which is just a number. I'm using MS Access and an OLEDBConnection as the method. I've created the relationship in MS Access and also created the datarelation in the VB.NET code.
I am able to submit the information into the database into the two tables but the foreign key isn't being populated therefore not being linked to the other table.
I think it's probably a very simple fix, but it's been eluding me for a good 8 hours or so. I am using a dataset and 2 data adapters, one for each table.
Code:
View 1 Replies
Apr 18, 2009
I just watched a video from Beth Messi about setting up a primary key and foreign key on a table.
I created two tables, one called customer and the other one called orders CustomerID is the primary key to the customer table OrderID is the primary ket to the orders table and CustomerID is foreign key to the orders table
Beth Messi said that this would maintain the integrity of the tables and she also mentioned something about setting up a cascade delete so that when we delete a record in the customer table, the customer's order in order table will get deleted as well.
how I can set up the cascade delete, Meanwhile, I tried deleting a customer record in customer table - a customer with orders, and I got the following error when I clicked save.
The DELETE statement conflicted with the REFERENCE constraint "FK_Orders_Customer". The conflict occurred in database "C:DOCUMENTS AND SETTINGSLOUISLOCAL SETTINGSAPPLICATION DATATEMPORARY PROJECTSWBINDEBUGTEST.MDF", table "dbo.Orders", column 'CustomerID'. The statement has been terminated.
Shall I use try catch to warn the user that the record that I tried to delete has an order? They can't delete the customer unless the orders table's record is deleted first?
View 4 Replies
Jul 25, 2009
I recently made a database that saves user information into a MS Access database from a form.
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
objDA = New OleDbDataAdapter("SELECT * FROM CDetails",
[code].....
View 3 Replies
Aug 15, 2009
In a windows form i want to fetch data for the combobox1,combobox2,combobox3 and combobox4 from the BankAccount table and fetch data for combobox5 from the TransferMoney table and fill the dropdown list of these combobox's at the form load event.
Imports System.Data
Imports System.Data.OleDb
Public Class Form1
[code].....
View 1 Replies
Jul 25, 2009
I recently made a database that saves user information into a MS Access database from a form.
Code:
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSave.Click
objDA = New OleDbDataAdapter("SELECT * FROM CDetails",
[Code]....
Now when they go to the next form, I have labels such as lblFirstName, lblSurName ect. I want to display the information that the user has inputted into these labels. How can I fetch data saved into the database and display it onto these labels? and how can I select rows?
View 3 Replies
Oct 9, 2011
I need some clarification. I'm planning to make a Scheduler program where it will fetch data from a MS Access Database, and I also want it to upload the data to a web server (MySQL Database) in JSON Format.
In the first process which is the fetching, I'll use System.Data.Ole.db namespace. This namespace mostly worked in MS Access. In the 2nd process which is the uploading, I am planning to use FTP protocol and should be JSON Format.
I was just confused with the second step, is FTP protocol applicable for this process?
I will make an Android apps to view all the data that will be saved on the web server.
View 2 Replies
Jul 20, 2009
I am using a number of tables on my application and two of which have a foreign key constraint I have set between them. When I change the account number on the main table via a combo box all of the relevant information for that table on the form is updated accordingly. However, the child table which has a foreign key reference to the Account Number of the main table is not updated when the acocunt number is changed. I have set the update to cascade in the references but still am having issues.
View 5 Replies
May 26, 2006
I want to be able to get some data from my database table, given the value of the primary key. This is what I have so far:
projectName = DbDataSet.Projects.FindByid(projectId).name
where projectName is a String, and DbDataSet is my dataset. The variable projectId is the ID of the row I want to extract the data from, but every time I run my code I get a NullReferenceException.
I know that the row with the primary key value of projectId exists because I can see it when I view through server explorer.
View 11 Replies
Jan 26, 2011
This is a follow-up to a previous question regarding locking on two List(Of T) objects. Suppose I have a function like this:
[code]...
which resides in a class that declares List1. In a multithreaded environment, I now understand that I should have a private locking object for List1 and lock List1 whenever it's modified or enumerated. My question is, should I do this:
[code]...
View 2 Replies
May 21, 2011
I have managed to successfully create a logon page and have created a form to insert data into one of my tables using text boxes and a "Save" button, however the first field in the table is the named "CustomerID" and is set to Autonumber, this is the primary key of the table. If I enter a record into the table in Access it automatically enters the next valid ID however when I can't seem to make this happen when entering data via my VB form!
View 7 Replies
Aug 24, 2011
Suppose the given picture*(consider the picture as a web page)* is a web page...i have saved this web page to my HDD...now i want to parse/copy data from a specific area from the web page and store it into the database accordingly. Is this possible?? I wanna know if this thing is possible??If yes then how??
View 2 Replies
May 8, 2009
i have a database file in .txt its a regional dictionary file released under GPL. [Code] How do u i fetch a word from it? Like if any one type abbey in a textbox, the first word in this sample, it should return the meanings numbered 1,2 & 3. How can it be done? can any one give me a sample code? Its for making a free software.
View 2 Replies
Jul 19, 2010
I Have a data table like this:
UserID Username Password Email
an a dropdownlist that is binded to this table
DisplayMember is Username
Value member is UserID
now how can I get forexample Email when an Item is selected?
View 3 Replies
Mar 29, 2012
fetching data from simulated model
View 1 Replies
Nov 20, 2010
i have two item in form it is---1 is textbox and 2nd is combo box.now i have single value in textbox but there is a multiple value for a combobox with is totally depend on a value of textbox.*i am already add data to the backend files ... in which 1 columns that is called column A it's value is for textbox and 2 column that is called column B it's value for combo box When i write in textbox it's dependent ALL value can be get in the combo box.Can any one solve my problem..
View 1 Replies
Apr 28, 2011
i am making a website for trading, with trading feeds coming from a source in an excel sheet. I have to show data from the excel sheet in a gridview. When i make connection it will fail due to rapidly changing data; each cell in the sheet changes value 1-3 times per second. I am using an Ajax Timer of interval 100. Here is my code:
[Code]...
View 2 Replies
Dec 16, 2009
I am using VB 2005 professional and SQL Server 2005 express edition.
For the last two weeks I have been trying to have a datagridview control on a form that will have datasource from a dataset with two tables that are related. I want child the column to be a ComboBoxColumn where userts can select options and update the other data(from the other table).
I have two tables in an sql server 2005 database named computers:-
computers
locations
Table computers looks like thisID is the primary key column)
ID Location
Computer139
Computer240
[Code].....
With the location column being a ComboBoxColumn so that when a user enters a new ID say Computer5,they have a choice of a dropdownmenu for the Location column. In the database table computers the item should be saved as well as the index value(to correspond to the LocationID).
View 1 Replies
Jan 15, 2012
I used a class MyList and with the Help of this MyList the combo box named cboCity was filled with City Code(like 1001,1002,etc..) as Value member and City Name (like Canada,California etc...) as display member.
Public Class MyList
Private _dispName As String
Private _valMember As Integer
Public Sub New()
[code].....
The value members 1001,1002,1003,1004 get inserted as per cbocity(combo box)display name selection , into the database and during the retrieval of the record the value member is obtained and based on that for eg:when i get 1001 the selected item should be Canada.I tried many ways while fetching the record and set the selected item but all fails .
View 1 Replies
May 26, 2010
I fetch data from an SQL Express database table named ALARMLOG to a datagridview1. One of the columns of ALARMLOG is "TheTime" which has datetime data type values. This values are in the following format "22/04/2010 13:23:45 PM".When I fetch the data to the datagridview1 I get "22/04/2010 13:23 PM".The problem is that I can't display the seconds in datagridview1. I tried the CORVERT command of SQL in order to convert from datatime to varchar but nothing...
[Code]...
View 2 Replies
Dec 22, 2010
I have been used getelmentbyid in past in vb6 using webbrowser control and internetexplorer instance But in vb.net i tried to fetch webpge using the httpwebresponse Which gives the html / source in the form of sting Is it possible to fetching data by getelementbyid using httpwebresponse and httpwebrequest method ?
View 11 Replies
Jan 16, 2012
How to insert multiple data into mssql without using loop?i'm developing a clinic management system, while doctor may give few medicines to patient,therefore i hope inside my database,the data will look like [code]
View 2 Replies
Mar 10, 2009
I am not particular with the database approach of Foreign Key a manner wherein a data related to another data. Table1 > Relations > Table2 How to make a foreign key and how to use that in coding ?
View 9 Replies
Mar 17, 2011
I have a header table and a related details table with a one-to-many relationship from master to details.I understand that I will have problems saving details if the master data isn't already there, and I've been working around this. (VS 2008, SQL Express 2008, app is running on XP)
I've been getting around this by checking if there's any detail data on the save click event and warning the user that they need to save the master first before adding details.So the user then removes the detail, clicks save, and then adds the details and clicks save again. Although not good, that's been working OK, but now I need to make the details mandatory. So at the moment they can add a new record, save it and no details.What I would really like to do is to save everything at once. I saw a related post that said I needed to use a transaction, Is that the best approach? Or is there a way to save the master first then the related details all when the save button is pressed?
View 4 Replies
Nov 28, 2010
I have master detail form with two datagrids. customer and order detail.I have relationship between customer and order detail on customerid.How do i delete record from order detail when i click delete button to delete record from customer datagrid.Here is the code so far.
Private Sub btndelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btndelete.Click
'Me.CustomerTableAdapter.Fill(Me.CustomerDataSet.Customer)
[code]......
View 1 Replies
Aug 23, 2011
On a client i have an anonymous list containing a multi-column primary key previously selected from the DB.Then i need to select all the records from the DB that equals the primary key list i have stored in the memory.[code]
View 1 Replies
Mar 2, 2012
How i can import row from TABLE1 to TABLE2 without primary keyfield or adding correct value to primary key
i tried with two different codes, but result is same, it says: "In the column "Key"a constraint on the uniqueness.[code]...
View 2 Replies
Aug 17, 2011
So Im making a program with 2 different data tables where different columns from those tables are used in different tabs in the same form. This all works good and well so far, but I have one issue which just drives me mad, and a couple minor ones.
1. I have an ID column in each data table marked as Primary Key, Unique and Identity. Problem is that even if I choose to hide this column it just randomly decides if it actually is visible or not. Most often its visible. I dont get it, doesnt this function work? Do I use it wrong? Im not using any code for this, just right click on the data grid, press Edit Columns... And change the Visible to False. It works for all other columns all the time as far as I can tell, but for my ID column its just random.
2. Im wondering if its possible to align the text in some of the columns of my data table to the right, note I only want some of them, not all of them.
3. Is it possible to do maths with the values from the columns in a table on the same row? Like for example having column 3 = column1 + column2?
View 3 Replies
Dec 15, 2011
I'm creating a form that will be used to update fields in a table. I don't want the user to be able to update primary keys though, so I'm trying to disable the textbox so it can't be edited.
The textboxes are created during runtime, so I'm trying to create an If loop that will see if it is on the primary key column, but i'm unsure of how to do this. I tried doing this:
If dt.Columns(i).Unique = True Then
t(i).Enabled = False
End If
But this didn't work. I found an option called PrimaryKey which would go dt.PrimaryKey... something (I'm guessing) but just unsure of how to use it.
View 2 Replies
