Currently I add data to a hash table, then later on I loop through the hash table. To my horror I discovered that when you use FOR EACH with a hash table it doesn't return the items in the order you added them.I'm looking for a collection that I can add, edit and delete items from and loop through from start to end in that order.
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I was asked by an employer to sort a hash table. I always thought that the usage of a hash table was in a way non-sort friendly. Am I wrong in thinking this, and if not can you point me to a good VB.Net(Yes Kill me now, but it's an old system) method of sorting a hash table.
View 3 RepliesI have:
string s = "A=1,B=2,C=3";
I need the output in hashtable using LINQ. Hashtable should be filled as
["A"] | 1
["B"] | 2
["C"] | 3
i need to create a hash table using a multiplication method and i need to create an array of linked listso how i can to create array of linkedlist in vb or c# ?
View 1 RepliesI have a register.aspx and a login function and i am using vb.net
in my register.aspx...i have a user name textbox and a password text and a submit button. IF the user click on the submit button, the password will be hash and store with the username in the database table called "Customer"
1st Qn: i have a problem is that i never try before hashing, so i not sure how to code it , hopefully if someone got a sample or example to teach me it will be nice
2nd Qn: besides that, in my login function, how am i going to compare the hash value for password that is store in database with the password in the textbox to allow to login?
I have about 100 strings that depend on an integer value. There is potential for the list to grow to 255. What is the faster/preferred method of assigning the string based on the passed integer, a hash table or a switch statement. I googled around and can't seem to find anything that compares the speed of the hash table lookup vs. the speed of the switch statement. Is there an easy way I could measure the speed myself or any links to articles describing the performace of each method?
View 4 RepliesI would like to know the best, or standard, way to accomplish real-time client updates in a small multi-user application using an access data table as a data source.
Specifically, this application will be used by 3-4 people. It uses a datatable which is filled on form load and bound to a datagrid at design time. The datatable is stored on a shared drive. The data table on the shared drive is updated in two ways:
1) Users can update the datagrid which then updates the datatable on the shared drive via the data adapter's Update method.
2) A server application does some work on some text files, periodically updating the data table.
I need the clients to reflect the changes to the data table on the shared drive as closely to real-time as possible. I know that the data table stored in memory on the client is disconnected from the data table on the shared drive, so I must query again to get the updates.
I have two questions:
1) Is there an alternvative model I can use which is connected, and which will automatically reflect the updates in the data table on the shared drive?
2) If not, what is the best way to check for changes in the data table (so I can know when to call the data adapter fill method)? I am planning to poll the drive for a change to the .mdb file, raise an event and then fill the data adapter when the event is triggered. I am using this method successfully now to check for changes to a text file in another application, and I know how to implement it
have made the data table in vb code, and it works flawlessly. It gets its values from labels which are part of a calculation.It shows the information to the user in a datagridview. Now i would like it to add new rows and fill them in if the user has already entered the data once and it has been logged in the datagridview.here is the current
'DATA TABLE
Dim Table1 As DataTable
Table1 = New DataTable("CF Log")
[code].....
I am writing a string of about 120 characters to a 2D barcode. Along with other text, the string contains a unique ticket number. I want to ensure that someone doesn't generate counterfeit tickets by reading the 2D barcode and generation their own barcoded tickets.
I would like to hash the string and append the hash value to what gets embedded in the barcode. That way I can compare the two on reading and see if the data had been tampered with. I have seen several hash function that return 64 bytes and up but the more characters you embed in a 2D barcode the bigger the barcode image becomes. I would like an algorithm that returns a fairly small value. It would also be nice if I could provide the function my own key. Collision is not that big of a deal. This isn't any kind of national security application.
I've got the following code for a password but need it the program to set a certain password. At the moment I just type in anything and it lets me get on with the program.
[Code]....
I have SQL 2005 table with columns TypeId(int) & Description(ntext datatype).
The Description column has XML file content as value in the table.
Now i want to read the data into a dataset in VB.Net. How to do it in VB.Net. I am using Winforms and VB.Net in VS 2005.
I have SQL 2005 table with columns TypeId(int) & Description(ntext datatype). The Description column has XML file content as value in the table. Now i want to read the data into a dataset in VB.Net. How to do it in VB.Net. I am using Winforms and VB.Net in VS 2005. Below i have given the xml file content.
<?xml version="1.0" encoding="Windows-1252" ?> - <SummaryPageComponent xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema"> - <categories>
[Code].....
I am having to create a data adapter to pull data into a dataset, then loop through that dataset in order to add information into a new column from a separate data source. My first data source is access. My second data source is oracle. Here is the code I have to do this, which works well when I show it in a grid.
Dim da As New OleDbDataAdapter("SELECT tblSummary.WorkOrderNumber, tblLabor.Crew, tblLabor.NumberOfMechanics, tblLabor.NumberOfHoursPerMechanic, tblTasks.TaskNumber, tblTasks.TaskDescription FROM (tblLabor tblLabor INNER JOIN tblTasks tblTasks ON tblLabor.TaskID=tblTasks.TaskID) INNER JOIN tblSummary tblSummary ON tblTasks.JobPlanNumber=tblSummary.JobPlanNumber WHERE
[code]....
how I can search through this data table. For instance, I want to see only rows that are in this data table that have "Replace" somewhere in the "Description" field, which is the field I added from my second data source. How do I do this? Is there an easier way to do all this instead of filling my dataset from the first source and then adding columns from the second source by looping?
I start with a text file containing information such as this: Monday, Tuesday, Wednesday, Thursday, Friday 12:00:00.1, 12:00:00.1, 12:00:00.1, 12:00:00.1, 12:00:00.1 I made up the values of course but the idea is exactly the same. I need to have an if statement that if the text document has a record of Monday, then it is to put something like an X in the corresponding column in a data table. I'm sure I confused this way more than need be but I hope you get the most of it and I can elaborate if need be.
View 6 RepliesI tried to follow this advice, but I still run out of memory.
[URL]
Basically, I am reading all the bytes of a 1 gb disk and I want to try and do a md5 hash on it. However, when following this example, my cryptostream gets too large a System out of memory exception.
Is there another way to do the md5 hash over some much data?
I am currently reading it into 10 million bytes arrays at a time. Can I hash the first array, and then use it as a seed for the next array, and so one, like you might do to a CRC32 calculation?
VB.NET:i want to select data from sql server 2005 DB table and displaying into text box that depends on combo box selection using VB.NET
View 1 Repliesmy below code not able to transfer data gridview to sql database table... giving below error : -
"Object reference not set to an instance of an object."
Protected Sub btnSave_Click(ByVal sender As Object, ByVal e As EventArgs) Handles btnSave.Click
Try
[Code].....
Has anybody ran into this error before?
View 2 RepliesI am newbie in VS 2005 and started learning. Can you please tell me how to Pop up the data from a table when there is a key press in the textbox.
View 11 RepliesI have exported data from a SQL Server table into a XML file and the output looks like this:
Filename = 11190.xml
Table name = LRTest
<NewDataSet>
[Code].....
Now I want to save the above XML file into my SQL Server 2005 table
With the same columns using vb.net windows forms, in every exported xml file there are 100 to 200 records. .
I'm new to Visual Basic, VS2005.I've added a Table to the WebForm. At Default.aspx this code was added automatically:
[Code]...
an error message when I am trying to load the data into a listbox and the value in the table is NULL. I am new in programming and I am using vb2005 Here is my
[Code]...
I have three table and I want to put the three table's data in one variable and from that variable i will produce the datatable and then want to write the data in CSV file.I am Following this step..
Void
GetDetails()
DataClasses1DataContext
[code].....
I have a login form that consists of 2 text boxes: txtUser, txtPass. Now these are not bound to any data table & I don't what them to be bound. When a new user enters his user name & password, I want to add these on a data table that has two columns: User, Pass. Data table information: Data Source = Login.accdb, Data table = LoginTable, Connection = LoginCn. I use visual basic 2010. So how do I do this?
View 1 RepliesI have this code to edit the datarow of my table adapter but t doesnt update the table. I think i have a missing code that's why but i cant figured it out. by the way im using vb2008 and SQL as my database. [code]
View 3 RepliesI 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]...
While am using the below code it was throwing an exception update unable to find table mapping [Customer] or data table customer.
[code]...
I have 1 access database with 3 tables How do I make the combobox get data from one table and input it to another table?ex.I have a table with all my Carriers and another table with jobs that are assigned to Carriers?
View 3 Repliesi have a combobox on the form and a datagrid viewer .no i want to display the table which selected on combo box..
View 1 RepliesI have a form that fills a table adapter with this:
Me.Scratchpad3TableAdapter.Fill(Me.MDRDataSet.scra tchpad3
and what I'd like to do is when users edit something on this form that they post the changes to a table called exceptionsedit which is not part of that dataset. What I don't know how to do is to how to insert those edits to the exceptionsedit table.
