I need to load a list of tables and linked tables in an MS Access Database into a combo box. I have this.
vb.net Imports System.Data.OleDb
[Code]...
1. How do I load the access tables and the link tables into my combo without the system tables showing up?
One of the things I'm trying to do is work out the total profits for a company, reading from an access database comprising of two linked tables. All the information needed for the calculation in question (Fees, Sold/Bought?, Cost/Income) are found in one form (Financial) and I want to read this information and carry out the required calculations within a sub.
Here is the calculation in Pseudocode I wish to do:
Do
If SoldBought = Sold then
Total = Total + Cost/Income - Fees
Else: Total = Total - Cost/Income
Read Next Record
Loop Until End of Records
[Code] .....
Unfortunately, I encounter an error with the above. I get the following error;
"There is no Row at position 0".
How I could get this in motion - I've been stuck in a rut for days trying different things out and I've come to accept that I can't do this alone.
This is the code that i did to fetch data from the database and filling it to the combobox dropdown list at the form load event:
[Code]....
I have a system that gathers raw data from electronic devices, uses that data to populate a set of tables and allow uses to add/edit certain data and report on it. (Kind of basic right...NOT) There are 3 applications that I've written that use the same database.
One is a client that is on 3-4 user machines which allows them to see the data that has come in and work with it.
Two a Data-to-Information process program which takes the raw data, checks up certain information and puts the results into the database.
Third is a data gathering app that interfaces directly with the electronic devices and about 10 times per day places the raw data into a single table in the database.
If a user is in the 'client' application the data processing application crashes all over the place:
1. Database file already in use.
2. Unrecognised Database format
3. File locked exclusively by User on PC X.
Almost always on a different line of code and once when I made it retry over and over I managed to corrupt the database and had to Compact and Repair it to fix it. If no one is using the client everything works perfectly. On each client machine is a database with linked tables to the server machine. The machine that is running the Data processing is the server and the processing is using a database in a different folder that also has linked tables.
I have gone through all the recordsets in the Data Processing application and made sure that they are only using ForwardOnly and Read Only. They edit the data only with Insert, Update or Delete queries. I'm about to do the same in the Client Application as it seems to be the one that is locking everything all the time. The client machines haven't crashed on that error at all. Does it matter which version of Access is on the client and server machines? (All the clients have Access 2003 and the server has 2007 but the Database was created in 2003). Should I just convert the Access database to SQL server and be done with it?
I added a few items in the combobox dropdown list at the form load event. [code] At the runtime I dont want to allow the user to write something in the combobox as a text.The user can only select an item from the dropdown list of the combobox.
View 13 RepliesI am writing a small program to update data in a SharePoint list. Now where I cannot develop or use applications for SharePoint unless I am on a SharePoint server, I thought I would cheat the system by using Access to link to SharePoint lists, and then use Visual Basic to play with the Access tables. I need additional functionality other than what VBA can provide me, so that is why I am using the VB layer.Is it possible that this is not permitted? Whenever I try to update an item in the table, I receive the message:
"cannot update '(expression)'; field not updatable"
The word 'expression' here is not a filler I added, this is the actual error.If I try to make the edit manually in the table using Access, it works fine (I haven't tried it through Access VBA yet...).
How my code works is this:I have a Dataset added to the project which connects to the Access database. I add one of the tables to the dataset and create a Class object to reference the table adapter (essentially a Data Access Layer). I can read all of the data fine, and when a change is made in SharePoint, my application sees the updates when it refreshes. But when I try to write back to the table I get the error message above.
For
Each r As
DataRow In TableAdapter.GetData.Select("Name LIKE '*" & FileName &
"*'")
[code]....
There are other columns in the table and some of them have default null values. I only want to update these two fields, but it almost seems like this is not possible. I thought I might be somehow opening the Dataset in a Read Only mode, but I can't seem to find that option anywhere.
First timer here, I love the site!
Running:
- VS 2008
- Sharepoint 3.0
- Access 2007
- Windows Vista (The machine I'm developing it from)
History: (Do excuse me if I don't reference different methods I've taken so far correctly, I'm still learning!) I am building some search software for a law firm that I work for in Australia. It's all coming along really well, but I seem to have hit a snag getting data out of sharepoint lists and into my project!
I first attempted to add a web reference to sharepoint and after a while was able to pull in all of the data from the lists, fantastic!(OR NOT!). The issue then was when I attempted to load it up into an array using XMLNodes, whilst it loaded up fine and I could see all the data, if there was a null value in one of the columns, it wouldn't pull that null value across, therefore, I couldn't really use the data...
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I've written a program that works perfectly well when installed on my development PC, but when I use the wizard in "Build-> Publish" and install the software on another computer it complains it can't find the DLL that I've linked to.The DLL comes from a programmable board that I'm linking to, so I don't have access to the source code, and I've included it in my project using the following lines:
Declare Function InitMbee Lib "C:UsersMartin & CelinaDesktopVBminimb.dll" () As Boolean
Declare Function SetOutputs Lib "C:UsersMartin & CelinaDesktopVBminimb.dll" (ByVal outputs As Integer) As Boolean
However I've not included the DLL in any other way, so I'm wondering if I have to add it to a list of items that need to be included with the installer, or if I've declared it in such as way that it needs to be in the same place for all installations.
SQL statements:
SQL = "SHOW TABLES;"
Try
conn.Open()
The remarked area works fine when I'm accessing a specific table. I've successfully inserted the products_model field into the combobox too. The datagridview does show the table names in the db using the SHOW TABLES sql statment, but I'm not understanding how to get this info into the combobox instead.
I am absolate new to vb.net .can some one help me to write a query that will display list of tables in combobox.using the code bellow i can create table but i want to be able to add all the avilable table names in combobox.Imports System.Data.OleDb Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim Cmd As OleDbCommand
Dim SQL As String
Dim objCmd As New OleDbCommand
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I'm making a combobox on a form. I want the combobox to have a list of choices from a table in a db. The two columns are a String and a Date. I want the date column to only show the year. I'm hoping I have the code right as it is above, but I'm not positive I've done the whole date thing right.
[Code] my issue is that now i need two cases, first i need a query that will return the date created and modified of the table and i also need to know if its possible to query a list of table names in the database ordered by date created but that have a certain thing in their names. for example the database contains the following tables: [Code] and what i need the query to return is the tables that contain "Data", settings and employees are for the other functions of the program. so the query should return the 4 data tables in order of date created. but i have no idea how to go about doing that in the query, does anyone know how this is done?
View 6 RepliesI've found alot of examples for add/edit/delete a single table. In VB6 ADO you could load multiple tables into a recordset using the join command. Then manipulate or modify the data.
I've found how to retreive multiple tables like,
Da = New OleDb.OleDbDataAdapter("Select groups.groupid,groups.userid,lots.groupid,lots.lotid from groups inner join lots on groups.groupid=lots.groupid order by groups.groupid asc", DB) But the only way I have found to update is to use seperate Update commands for each table.
I have the following:
a table of addresses and a bindingsource for the table
a enum list of address type: 0 = "Mailing", 1 = "Physical", 2 = "Shipping" etc...
I would like to bind the datasource of the combobox to the enum so it displays "Mailing", "Physical" etc. Then I would like to change the bindingsource position of the address table based on the user selection of the combobox.
Here is what I have so far:
cbxAddressName.DataSource = New BindingSource(ApplicationEnums.GetEnumList(GetType(ApplicationEnums.CompanyAddressType)), Nothing)
[Code].....
For some unkown reason, my database tables will not drag and load onto a vb form, just get a circle with a slash in the middle. Trying to tanslate the table into textbox's.
View 4 RepliesI have an Access frontend with a lot of tables linked through ODBC to a MySQL backend. I have a VB.net application that sometimes adds columns to the tables in the backend, and when that happens, I need to refresh the link to the table in the frontend from the VB.net app to show the new columns.I'll consider just about any solution as long as it doesn't require restarting MySQL or Access, and will allow me to refresh only the links I need to refresh (which I know in advance) as there are hundreds of links and tables in the frontend.
View 1 RepliesI dont know how to dynamically populate a dataset based off the tables in an existing database.Once I can get the dataset to populate, I can then move forward with the next step of the project.
View 1 RepliesHow can MS-SQL Database access wise vb.net
1-How can load data to combobox from table filed?
2-How can check how meany data in the database filed.
I am very familiar with VBA and have been using access and excel to create applications that connect using ADO and/or linked tables.I'm looking to start developing simple Windows applications for my company using Visual Basic, that will connect to Oracle and SQL Server Databases using ADO. What do I need to accomplish this? If I purchase Visual Studio 2008 Pro, will it come with VB? And do I need anything in addition to this in order to connect to SQL or Oracle databases using ADO method?
View 7 RepliesI have a large form that is set up from master-detail datasets in Visual Studio 2008.I havene master table with a large amount of detail tables. Several of the detail tables also have detail tables linked.Now I need to add a master table that sits on top of my existing master table making it a detail table.
View 7 RepliesI'm getting this error 'column' argument cannot be null. Parameter name: column at the bold character instruction. Also I would like to know how to relate two tables with two key columns in each table
Dim connection As New OleDb.OleDbConnection(strTextoConn)
Dim EnPartesdataSet As DataSet = New DataSet("Enpartes")
Dim strsql As String
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I have an VB application that I developed in Visual Studio 2008. The back end is SQL. Application stores quite a bit of information and gets updated daily by users. It also connects to AD to get u/p, adds new accounts in AD and adds mailboxes. Users connect to it through Citrix. We noticed big spikes in memory usage. The executable itself is less than 5Mb; if I run it and it opens main form - memory usage jumps to about 19Mb, open a report - it jumps to 80 Mb. If I open the form that is linked to multiple tables - it jumps to 157 Mb. Once users start pulling new information in, update it and connect to AD or Exchange - it could jump to 250 Mb. Also noticed that if user with read only rights has application opened and idle - memory usage constantly changes with a pattern
like 17Mb - 19 Mb - 15 Mb - 17 Mb and so on. This user wasn't even using computer at the time. In general - what could cause such jumps in memory usage? What is the best way to prevent it? On the server we have Windows Server 2003 SE
I have one application create tables in database dynamically during run. Another application need to find all these tables' name in the database. how should in do in vb.net
View 7 Replieshow to correct my code.It seem dont have error but it only able to load 1 picture only.In my code here i am using combobox to load a image into Picturebox. I got 3 item in combo box and 3 image which need to load in picturebox.
Private Sub CBpayment_SelectedIndexChanged(ByVal sender As ystem.Object, ByVal e As System.EventArgs) Handles CBpayment.SelectedIndexChanged
PBOffice2.Image = My.Resources.dollar_us
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I am working on a CMS system for my business, and need to be able to generate notifications dynamically into a control panel. Please note, I am using .NET 2.0, coding with VB and my data is all held on a MySQL database.This is pretty simple for most aspects, but as the whole thing is dynamic some things are proving more difficult.I have a set of tags which are dynamically generated with a repeater as follows:
<asp:Repeater runat="server" ID="locationRepeater">
<ItemTemplate>
<p id='locationNotification' title="<%# Container.DataItem %>" runat='server'>
COUNT DATA NEEDS TO GO HERE
</p>
[Code]...
The data is really, really, simple, all I need to be able to do is query a table on my MySQL database for COUNT of ID WHERE locationName = Container.DataItem during each loop of the repeater... but I don't know how to do this.I'm thinking maybe I have to do this first, create a table in memory somehow, but I am afraid I have no idea how to achieve this.
Has anyone got any examples of a similar thing, it's kind of binding to a repeater from two datasources... each task is very simple, but I don't know how to put it all together!
I'm looking for a way to combine a field from multiple tables into a single field in a new table. Because the data populating the tables is coming from an outside source, I would prefer not to change the data in the original files. I have a separate table for each year because this is the way the data is provided. The field layout is not consistent from year to year, but each year there is a field that we'll call "score." I'd like to pull the field "score" from each year's table and have it populate a "score" column in a new table along with the year of the data so that all the years' scores are in the same place. Is there a way to do this using Visual Basic + Access?
View 3 RepliesI have code that connects to queries in an access database.
[code...]
Is the data not filling in because of the schema information not being retirieved? If so, is there a way around that?
I am trying to create a button on a form that will open a connection to a database and list all the tables in the database inside a listbox. Everything I have read indicates I can associate a single table to a form, and have no idea how to:
a. Create code for the button to access all the tables in the database.
b. Display that list in a list box.
The text that I am using is murach's ADO.NET 3 database programming with VB2010, and I am less that thrilled with it.
When the form loads I want to fill the combobox with the data present in the database. So I did the below
Private Sub BindCombo()
con = New OleDbConnection("Provider=Microsoft.Jet.Oledb.4.0;Data Source=C:UsersGautamDocumentsVisual Studio 2005ProjectsF1pracF1pracBank_Account.mdb")
con.Open()
cmd = New OleDbCommand("Select * from BankAccount", con)
[Code] .....
Doing this code the data is added up in the combobox dropdown list. But when I am selecting a data from the combobox dropdown list,the all the corresponding data of the other combobox also get filled automatically. I don't want to let the other combobox filled with their data automatically....
For the past 3 weeks now, we are encountering a sudden loss of table in our database, but with that. our .mdf file is still on its same size before this disaster comes along and again..anyone had encountered or know how to solve this problem.
View 3 Replies