I am in the process of revising code to use TVP to send data from our VB.NET app to the SQL 2008 DB and try to keep all the writes atomic.[url]...
I am in the process of creating all the in-code datatables to be sent to the SQL stored procedure
However, I will have to create these datatables and datacolumns (then add the columns to the tables) repeatedly for multiple tables.
I am attempting to have my program select a file, create DataTables and then perform some other functions. I want to be able to open another file and re-do the same steps.The problem I am having is that I add columns to my Datatables and when I try and to open another file while one is already open I get a message that a column of xyz is already added how do I properly "clear my datatable" or perhaps that isnt even the correct approach? Here is the code I have that Opens a File
HTML
Private Sub OpenToolStripMenuItem_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles OpenToolStripMenuItem.Click
[code]....
This was working at one time but after adding to my project I must have placed something in the wrong place inadvertantly or it has soemthing to do with adding columns,?
I'm having a hard time joining 2 datatables and have the joined datatable as result. First datatable (labels) holds data including a printerid. Second datatable (printers) holds printer references (id > unc). I would like to have as endresult (joined) a datatable with all data from the first datatable with the field (unc) of the second datatable. [Code]
View 3 RepliesI have two datatables, which come from different sources. One is Sales, the other is Products. What I'd like to do is create a filtered version of Sales, in that in that it contains Sales which have a matching ProductID in Products.
View 11 Replieswhile this is first time I need to use some kind of database and I think that database is the way to go here while...
I need 'datatable's' that will be filled by user run time in a next way:
-Folder (fixed)
---User 1
[code].....
I am trying to create a LINQ query statement that retrieve intersecting data from 3 datatables (dt, dt1, dt2). My first attempt to do so with the following LINQ query statement was successful: [code] However in my design, I would need the LINQ query statement to be dynamically generated, because I want a user to be able to retrieve intersecting data entries from VARIABLE number of datatables. In this case, the first option is not as good as the "INTERSECT" query operator, with which I can just easily connect each SQL query statement with a "INTERSECT" operator. The problem is that my second attempt using the "intersect" operator fails, and after many trials and errors I still can't get it to work. [code]
View 5 RepliesHello I want to create a windows form application program that can create games something like Gamemaker or Klik & Play (butt less advanced) with D&D "Drag and Drop" events and actions.
View 7 RepliesTo create a program that asks for input then uses an else statement to create a handling fee balance.
Input: sales record - first name, last name, purchase amount, balance before purchase
Output: report - full name, old balance, purchase amount, handling fee, new balance
Definitions: handling fee is 5% of the old balance if the old balance is less than $1000.00 else it is 2% new balance = old balance + purchase + handling fee
Processing:
Ask for and receive sales information
Calculate new balance
Print output report
End the program when a purchase amount of 9999.99 is entered
I have a project to do for one of my classes that i need help on. Its and extra credit so im left on my own. Project Create a program to allow a student to create there own schedule. what i am trying to do is create a checkedlistbox for the student to check classes they are taking, and need something else to pop up or to show in another box or listbox the classes they can take for the next quarter. I know it has to do with if then statements but i dont know how to write basically:"if (class is checked in checkedlistbox) then ( these are the classes you can take)".
View 2 Replieshow i can write a program to create a shortcut in the startup folder of a different program. So i have one program on my computer that should run at startup, i just need another program to create a shortcut to it, and then copy this shortcut into the startup folder.
View 20 RepliesI am very very new to VB.NET and would like to ask a simple question. I want to create a vb.net program and allow visitors to a website to download this program. However, I prefer not to have visitors download a zip folder. I would like to have a program that just gives a prompt to save in a selected folder, once the saved file is selected it prompts the person to download, and then when finished prompts the person to run the program. The reason is twofold:
1. I don't like the extra step involved with unzipping the file. and 2. I don't like the visitors having to look for the "main" file program within the new downloaded folder. So is there any way to have just one file for others to download without having it in a zip folder?
I'm trying to create a program that installs required .dll's for a program due to a clean install..What I need to do is Get a value in the registry and use it for the program files path.. but I've noticed some pc's don't have the same configuration because of the version the user is using. Anyway This is what I have so far:[code].....
What I'm trying to do is find a registry key called "SoftInstallPath", if found I need the end of the path to goto the new directory(new_dll) not the old one (dll).. and if "SoftInstallPath" cannot be found.. I need it to find "ProgInstallPath" and use it instead and do the same thing.By the way I'm using Visual Studio Professional 2008 on a Vista x86 machine.Also error I keep getting is: Warning 10 Function 'FixPath' doesn't return a value on all code paths. A null reference exception could occur at run time when the result is used.
Anyone ever try and create a program in visual basic that interfaced with an USB device? For example say I want to build a clock but I want to have the software to control this through usb. I want to write the clock setting program that tells the clock what to set for time and date and things like that.
View 3 RepliesI want to create a program that will auto update another program i have created. I want (this program) to check for updates (from a txt file that i wil have in the first line the previous version and in the second line the present version) and if there will be a new version then start downloading and the progress bar will show the progress. How can i do this?
View 3 RepliesI'm trying to the contents of a datatable to a datatable thats allready in my form using the openfiledialog.[code]...
View 4 RepliesI'm trying to create a program that will merge two data tables (one from a database on a network drive, the other is found in a database on the local machine). Each datatable is identical in structure, only (maybe) differs in content. The structure has a primary key, dateCreated, and dateLastEdited fields (plus other fields). I would like to merge down from the network to the local database. If the primary key does not exist on the local db but does on the network, copy from the network db to the local table. If it does exist, check the dateLastEdited column and copy the latest row to the local table.
How would i set up the code to do this? Any assistance would be great.
How to intersect two dataTables in vb.net 2.0? I want to get common rows in two datatables and add it in third datatable.
View 1 RepliesI need to marge two datatables with condition. I have a datatable where the data comes from a local XML Database and another datatable where the data comes from a remote SQL Server. If any update made in the remote datatable I need to update/merge with the local datatable. Here is what I have so far:
Public Sub MargeTwoTable()
Dim SQL As String = ""
Dim RemoteTable As New DataTable
Dim LocalTable As DataTable
[code]....
In this code data comes from the remote database which updates a date getter then the local database . Both tables have "ID" as the primary key. The code is working well, but the problem is that when more than 1000 records are updated this function takes too long using loops.
I have two datatables which I intends to bind them to Gridview. But I need bit of the first dt and bit from second dt.
Second table has only one row that represents to every row in the same column in first table.
There is no primary key or relationship between two tables though.
For example,
I tried datatable.merge though. Didn't produce the last table i want.
I have a Main Table that contains all the distinct values in a DataTable.DataColumn. also have a Child Table that contains distinct values created by the user.I want to merge the Child Table DataRows that match on the Value column with theMain Table DataRows to create the New Table (shown below).I want to preserve the values in the Selected column of the Child Table.Here is my problem, if I use the DataTable.Merge method the DataRow that contains "888" in the Child Table is added to the New Table, but it doesn't contain a RowState = Added, thus I can't filter for added rows to remove them.
View 4 RepliesI am using VB Express 2008 and SQL Server Express 2008.I have one DataGridView on a Windows Form, which I am attempting to populate from two datatables. Both tables are identical in structure, but with data from two different dates. The respective SELECT statements are identical, except for the date; one calls for yesterday, one for today. I need a seperate Sum column from each table.I've tried to JOIN, UNION, and MERGE the tables, but that gives me all the data consecutively and I saw no way to seperate the days. I'm able to add DataColumns, and sum the fields with an expression, but is it possible to create DGV columns and bind them to the seperate DataTable columns? [code]
View 6 RepliesI am stuck with an issue.I have two datatables, with the same table structure, i need to select data from table1 such that the records arent existing in table2is it possible to do this in vb.net? if yes then how?
Table1(AAno,Agencyname,location)
Table2(AAno,Agencyname,location)
Criteria:Select AAno,Agencyname,location from table1,table2 where table1.AAno<>table2.AAno
I'm stumped trying to do an equivalent SQL statement in VB 2010 working with two DataTables, & am hoping someone could point me in the right dirction.I currently have two data tables with three fields each :- A, B, C. The data in field A is the same in both tables & could be used to join the two tables.How could I input data into a third data table having data from both primary tables ? Something along the lines of the following SQL code.[code]
View 3 RepliesI have a datatable with a yes/no checkbox in it and when I filter my datasource it loads form2. Right now I'm using this code to have a label's color as green if it's checked and red if it isn't:
Private Sub Customers2BindingSource_CurrentChanged(sender As Object, e As System.EventArgs) Handles Customers2BindingSource.CurrentChanged
If ActiveCheckBox.Checked = True Then
Label1.Text = "Active"
[code].....
That works when I do something like bindingsource.movenext because it's in the bindingsource_currentchanged event, but when I try adding that to the form_load it's automatically set to Inactive, color red. I figured it's because is set to checked = false, but what event do I use to make this work when the form loads?
What's the value of a checked checkbox for the update/delete/insert commands? Like dates are DateDateTimePicker.Value.Date. Is it something like this?
.AddWithValue("@Active", ActiveCheckBox.Checked)
I don't use checkboxes to often.
I've seen several posts on the subject, but none seem to answer this particular dilemma. I have two datatables that I obtained by querying two separate servers.[code]
View 7 RepliesI am trying to compare two datatables and generate a resultant datatable of rows that do not match based on customer number. The main table "Customers" contains all customers that have been placed in our system. I am trying to generate a table of customers, "dtResults," that we have not ever generated an invoice from a table called "CurrentCust".I would like someone to look at the attached code and see how I can handle the 'InvalidCastException was unhandled', 'Unable to cast object of type 'System.String' to type 'CustomerDataTable' error. Error occurs at line 43.
1
Option Explicit On
2
Option Strict Off
[code]....
using VB.net 2010 using DataAdapter and DataTables I'm trying to merge two datatables together and update a database with the results if I use the following code it works (though not ideal):
For Each tRow As DataRow In excelDt.Rows
accessDt.Rows.Add(tRow.Item(0))
Next
however if I use the following I don't get a error, it just doesn't update:
accessDt.Merge(excelDt)
accessDt.AcceptChanges()
For ease here I named the DataTables to describe where they are coming from. accessDt is a empty DataTable (to start) from a Temp Access database table with 1 or more columns in it and excelDt is a DataTable created from a Excel Worksheet with the same columns (same order as well) as the Access Table. Basically just trying to get the data from Excel into Access. They are using the same update command just swapping out which method is commented out. I have checked and accessDt does have the data in it before the Update is called using both methods.
I have a sequence that reads the selected Excel-file and displays the first row of the columns in the Excel. (The first Excel row has the column names)
Dim cmd As OleDbCommand = New OleDbCommand("select * from [" & tableName & "$]", MyConnection)
Dim dr As System.Data.IDataReader
Dim dt As New System.Data.DataTable
dr = cmd.ExecuteReader
dt.Load(dr)
With the above code I can read the the first rows of the Excel table and choose the names of the columns I like to keep. (By populating the first row to my ComboBoxes)
So, at the moment my DataTable dt has all the table header names but on the first row. And as the header names it has F1, F2, F3, ... F13.
How can I make my new DataTable dt2 take the first row of dt and make it the column names row? How can I choose which columns do I want to transfer from dt to dt2 ???
I have tried the following (Doesn't work):
Dim dt2 As System.Data.DataTable
dt2 = dt.Copy.Columns("F1", "F2", "F3", "F4")
DataGridView1.DataSource = dt2
Their system executes a DB query everytime they select something, causing performance issues. So I thought that I would read the superset of data into a datatable, and then whenever they want subsets, simply run against the datatable. I've done some testing and the performance difference is HUGE.The problem is how the screen paints on postbacks. The screen will temporarily go blank then the data will appear as expected. Of course, they don't want the blanking of the screen each time they select a subset of data.
I am currently using a repeater to handle the display of data due to the nature of what they want to display. A datagrid might be a good alternative for sorting functions, but I think it would still blank the screen when it data binds.How do I go about filling the repeater without blanking the screen? Is it even p[ossible? Logically I would think not but I don't have the experience. Or perhaps I can fill a datagrid without blanking the screen on the postback?I'd rather not have to go out to the database every time, but if that's the way to go then I can live with that.
I am working on a mdi project and I have a few different xml files that I need to read in and I would really like to use multiple datatables, but only one dataset. I have always struggled to get a datatable.readxml(filename) call to work without an invalidoperationexception b/c of the schema stuff. I don't understand it very well and in the past my workaround was just to make another dataset. I am trying to avoid doing that from now on. I have written a routine called readxml which will take a xml file name, xml schema file name, and a datatable name and return to you a populated datatable..but I can't get it to work.
Here is my call to the read xml method (comes from my main mdi form class during form load)
Dim dt As DataTable = globals.xml.readxml("SqlConnectionString.xml", "SqlConnectionString.xsd", "sqlConnection")
Here is my readxml routine, I will post two versions of what I tried attempt #1: use a string of raw xml and a xmlreader
[CODE]...