VS 2005 Using VB Through SQL To Read/write To/from File System?
May 21, 2009
I have an application that currently stores PDF files (and others) inside the database as BLOBs. The trouble with this method is that I've now got SQL Server databases in excess of 200 GB! I've finally figured out a way to still enable full-text search without needing to store the PDF files as BLOBs (yay! Adobe's iFilter isn't great.), but I'm having trouble designing the method for a client to get access to the files stored on the server's file system.
I want to place the files in a restricted directory on the server, so I can't simply pass a UNC path to the client and let them open the file from there either in a browser or using Process.Start(filename). I understand how that would work, but if that directory has user access granted, all sorts of security holes open up, right?So, what I'm thinking about is a way to have a SQL Server account that has read/write access to/from the protected file system directory. That way (in my mind), the SQL Server can take a file as it's loaded in through the import client (as a series of byte chunks) and write the file to that area of the filesystem. Then, when a file is requested, the SQL Server can bulk load the file into a varbinary(max) field and do whatever I want with it.
1. How can SQL Server take a stream of bytes and write them to a specified location on its local file system? (This is assuming that I want the import utility to be able to be run on a client machine and not require it to be run on the server itself.)
2. Is there any way to stream a varbinary(max) file to a web page out of SQL? I'm using a lot of PDF files that will have Fast Web View enabled, so if I can stream the bytes to a web page, the user will be able to see the first few pages of the document while the rest is loading. I thought about having the SQL Server read (bulk load) the file from the protected area and write it to an unprotected area just long enough to point a web browser to that location, then wiping the file, but that brings me back to #1 above and would THEN require me to be able to issue a delete command from SQL.
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Aug 20, 2009
I receive random AccessViolationException on client machines. I have captured the exception text and have pasted it below. Unfortunately this error is not happening on code that I have written it appears to be happening when the .NET is trying to draw a group box on the form. System.AccessViolationException: Attempted to read or write protected memory. This is often an indication that other memory is corrupt.at System.Drawing.SafeNativeMethods.Gdip.GdipDrawLineI(HandleRef graphics, HandleRef pen, Int32 x1, Int32 y1, Int32 x2, Int32 y2)at System.Drawing.Graphics.DrawLine(Pen pen, Int32 x1, Int32 y1, Int32 x2, Int32 y2)
[Code]...
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Feb 3, 2012
I am creating a program that uses text files to recall data and store them in a variable. My intention is to make this text file hidden so it will be harder to find and for other people to edit the data inside. I'm looking for a code that enables me to write to the file without unhiding it.
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Aug 2, 2010
I am reading an excel file. When everything passes the edits, it is then written to a database. However, if any cell in the row fails an edit, I would like to write a new worksheet (called Errors) containing all of the information from the row which failed.
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Oct 30, 2009
i want to read/write to some files.Specifically my application searches text files but i also want it to search binary files. The problem is : how will i know when the file is binary and not text ? Also how will i get the hexademical contents of a binary file ?[URL]
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Feb 27, 2012
Reading a .txt file in VB.net. My file path is C:UsersMyLilMulePepeDocumentsVisual Studio 2008Projectscurtain_calls.txt.
This is my line of Dim LoanOptionsFile As String = "C:UsersMyLilMulePepeDocumentsVisual Studio 2008Projectscurtain_calls.txt"
I can read the file when I run the program, but how do I write the file path so that someone else can download my program and file and read the file on their system?
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Mar 4, 2009
I have a VB.net 2005 app using the Microsoft.Office.Interop.Excel.dll version 11, deployed on a number of XP machines with Office 2003 installed. On one and only one machine I get the following error:Error -2147467261 Attempted to read or write protected memory. This is often an indication that other memory is corrupt.The line which triggers the error is:
xlSheet.SaveAs(strPathXLS)
xlSheet has been previously defined by
Dim xlSheet As Microsoft.Office.Interop.Excel.Worksheet
This should save an Excel file in a folder on the desktop. I can save a file from Excel in that folder, and create a new Excel file in it from the right-click option. The app is working correctly on the development machine and at least 8 other XP boxes on site.All Office and dotNet 2 updates have been applied.Office and dotNet have been uninstalled and reinstalled to no effect.
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Jul 1, 2010
I need to write a code that reads off a value from a another system's screen and compares with fixed value in .net 2005. The code should read all 24 lines of data from the screen and match to see if it is equal to the fixed value. What I have so far is:
Code:
Dim ObjScreen(6) As Object
Private ObjOIA_Area(6) As Object
Private OIA_Area As Object
[code].....
However the code is not working. and get an error. How can you select all or read line by line to get your desired result....
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Feb 27, 2010
i'm trying to read from a file and copy the text into a 2d array withought the selected item from a list box then rewrite the file from the array into the text file. however it writes a single part of the array times the variable count when i write back to the csv file. within the array everything is correct its only when i rewrite to the file is when the problems occur.
[Code]....
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Dec 29, 2010
i am using VB2008 to develop a Settings program for my game Lined World, creating with Game Maker. I've created a settings.ini:
[screen]
fullscreen=(off or on)
resolution=(800x600 or 1024x768)
[code]....
answers are depending on settings
now, i wanna create in the settings app the following:
"fullscreen" (radiobutton-on & radiobutton-off)
[code]....
if radiobutton fullscreen is on, [screen]fullscreen must be on, and if turned to off, the INI value should be "off".
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Nov 7, 2009
I'm creating a project where I need to store information in two files. As I understand, I can store information in a text file or a binary file?
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May 25, 2011
I am struggling with vb.net. I can read from a file but not able to establish a writing object. what I have so far is this.
Imports System
Imports System.IO
Imports System.Text
PublicClass EuroConverter
PrivateSub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code] .....
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May 19, 2010
I have a DB stored on our internal site and I want to read/write this file as it's updated. How do I download the file, then upload it after changes.Here is what I know about the link
Protocol: HyperText Transfer Protocol with Privacy
Type: XML Document
Address: [URL]
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Nov 17, 2010
I am working on a program with multiple collections related to one another for a school project. Each collection needs to have its own defined properties and have the objects written (1 per line) to a text file.
I have all of that working.
When reading the comma-separated line from the file, I want to place one of the properties of the object in a listbox (so that all the objects' names will show up in the listbox). I think I have this part figured out...
My problem is that when you click on the name in the listbox, I would like multiple text boxes to be populated with the appropriate, corresponding properties of the particular object in the collection...is there a way for this to be done?
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Dec 22, 2010
i have a structure of;
name
age
gender
location
then i need to read in a file into an array on the structure above, and pretend this is the file which has 3 people
george
45
m
usa
[code]....
so basically i dont get how to read in a file then put it in the array in that structure then make it into a csv file?and whats the difference between streamreader and streamwriter?
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Jan 3, 2012
I'm looking at an old web app I wrote and it is taking about an hour to read 4500 records from a DataTable so it can write them to a CSV file.
The DataTable contains... 376 columns
At least, I think that's what Excel's NL column converts to. I just looked up the column count now and had no idea there were so many. Our software vendor hasn't realized the value of dynamic sql statements for this process, so every software "upgrade" just keeps adding more columns rather than only selecting the ones needed. I cannot alter the SQL statement that generates the data
Depending on the data type, the data needs to be formatted in a specific format Data does contains special characters, such as commas The slow part is reading the data. Getting the data from the SQL server and writing it to a CSV is fast.
Here's the code. Forgive the mess, I wrote it back when I didn't know what I was doing and when I still was working in VB
Function ReadDataTableForCSV(dt as DataTable)
Dim sb = New StringBuilder()
Dim dataTypes As New Dictionary(Of String, Integer)
[code]....
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Apr 28, 2012
I was unable to find anything in my searches for XML or INI on the forum so i apologize now if this has already been asked and answered before.
I have been searching Google for days now, trying to find information on Reading and Writing XML files. I wish to use them to replace INI files in my programs.
I have been using VB6 for years now, but was able to get a copy of VB.NET 2003 really cheap and so i am trying to learn how to do the things i did in VB6 in VB.NET 2003.
I was able to find code to write to an INI file, but was not able to successfully read from an INI file with any of the code i found.
I have been able to find code to write an XML file, but when i try to update it, it replaces the old file with a new one, and the old settings are missing, instead of the new settings added to it.
i can at least start migrating to VB.NET 2003, or if you read XML and update XML data, i can switch now. Here is the code i have for writing XML.[code...]
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Sep 16, 2009
I have search on google but i have just find this function SteamWriter. This fonction for writing work, but the script create always a new file... I want write under the last line.And with your fonction, how i can read it line by line for use in select menu.
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Jul 11, 2011
I am new with VB 2008. I want to use txt file to store some parameters which is used entire of the application. I want following tasks;
1. creat the text file and give particular path where file must be saved.
2. Write values like TEXT{Tab} Value.
close the file
3.save the file.
4. open the file and read the only values and set into particular textbox on the form.
5. close the file.
Some times i need to search the particular value or TEXT. How i fullfill this task.
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Jan 18, 2011
How Can I load data into my datagrideview from xml file
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Jul 5, 2009
My text file look like this;
M48
METRIC,LZ
VER,1
FMAT,2
DETECT,ON
[CODE]..............
I must read the file scan for value T250,T169,T168,T170,T176............which ever value start with T after the line"DETECT,ON". then i must sort these values so that it will be in acending order. Then i must write back that values in same text file after the line FMAT,2.. Now i can read the lines which contain T. Then i store that lines in array. My code shows error when i used sort methode to sort the array which i store in array.
This is my code
Dim filename As String = strFileName
Dim i As Long = 0
[CODE]...........
The sort methode give me this error "Overload resoulation failed because no accessible 'sort' can be called with these argument". Why it shows this error and how i write back the value after sort. Can i use append Text methde.
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Mar 2, 2009
I'm new to VB.net and have only a few projects under my belt. This one has me stumped!! I need to open a file and search its contents hex byte by byte. (Similar to Hex editor). On finding a particular value I need to replace it with a set hex value then write and close the file. So far I have only managed to read / write the ascii equivilant.
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Jun 27, 2009
say i have this:
[Code]...
I'm very new to VB.net, have not a clue what i'm doing. I've googled around for over 2 hours now, and can't find anything, not even something that reads the info, and displays it.
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Jun 7, 2009
how do i read / write to a remote xml file with vb.net?
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Jul 26, 2009
I've got another simple problem. I want a 'survey' form to show up whenever the user opens the program for the third time. I, of course, have the survey form built.[code]...
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Sep 20, 2009
How do I read a raw byte array from any file...
Dim bytes() as Byte
..and then write that byte array back into a new file?
I need it as a byte array to do some processing in between.
I'm currently using:
To read
Dim fInfo As New FileInfo(dataPath)
Dim numBytes As Long = fInfo.Length
Dim fsAs New FileStream(dataPath, FileMode.Open, FileAccess.Read)
[Code]....
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Jul 2, 2009
I have a text file which look like this:
M48
METRIC,LZ
VER,1
[code].....
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Jan 12, 2011
After two days of looking I give up. The basic problem is that at the end of my program I need to be able to write out a text file and then read that same text file back in when the program restarts or reopens. The best and easiest way I have found to read in the file is to place the text file with in the Resources and use this code.
Dim ReadingIN As String = My.Resources.Mytext
So then I want to be able to change that string and then write it back out. Part of the problem is I want to be able to use this from a flash drive or a changing directory.
I have tried but it doesn't work
Dim WritingOut As String = ReadingIN + "Edited text"
Dim DirString As String = My.Resources.Mytext
If System.IO.File.Exists(TemperString) = True Then
[Code].....
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Jul 5, 2009
My text file look like this
M48
METRIC,LZ
VER,1
[Code]....
The sort methode give me this error "Overload resoulation failed because no accessible 'sort' can be called with these argument"
Why it shows this error and how i write back the value after sort. Can ui use append Text methde.
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May 31, 2012
I need to write the xml files into datagrid view but what i need also is to write to the datagridview and next to every row , the file name from where im reading the values from xml , example if have an xml file named : AIO , i want to read the values of the xml and add a column to the datagrid view that displays the name : AIO and so on the code that reads all the xml files and display there values in the datagrid view is below :
Dim FilePath As String = FileName.Substring(0, FileName.LastIndexOf(""))
Dim meter As New Stopwatch
Try
[code]....
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