DB/Reporting :: General Approach To A Db Project?
Sep 8, 2010DB/Reporting :: General approach to a db project
View 2 RepliesDB/Reporting :: General approach to a db project
View 2 RepliesI am often asked to create a very simple database front-end for friends or family, and the structure of the database (and application) is usually very similar.Right now I am always creating a class that handles all database interactions with some shared functions. For example, there's a function to run a general query and return a table, a function to save/load various items (depending on the application of course). The point is: the code is nearly always the same except for some slight variations.
View 5 RepliesI'm trying to make more use of namespaces and giving my project a more rigorous design, as it has been getting pretty messy.I was wondering,before I get started, is there a standard convention for the names and organization of namespaces?For instance,for a 3-tier program, should there always be a "UI", "Business",and "DataAccess" namespace (and is this what they're typically called)?Or should I just organize the project as I see fit?
View 2 Repliesfiguring out which multithreading approach to utilize in my current work project. Since I've never written a multithreaded app in my life, this is all confusing and very overwhelming.I've been assigned to take over work on a control application for a piece of test equipment in my companies R&D lab. The program has to be able to send and receive serial communications with three different devices semi-concurrently. The original program was written in VB 6 (no multithreading) and I did plan on just modding it to work with the newer products that need to be tested until it posed a safety hazard when the UI locked up due to excessive serial communications during a test. This resulted in part of the tester hardware blowing up, so I decided to try rewriting the app in VB.Net as I'm more comfortable with it to begin with and because I thought multithreading might help solve this problem.
My plan was to send commands to the other pieces of equipment from the main app thread and spin the receiving ends off into their own threads so that the main thread wouldn't lock up when timing is critical. However, I've yet to come to terms with my options. To add to my problems, I need to display the received communications in separate rich text boxes as they're received while the data from one particular device needs to be parsed by the main program, but only the text that results from the most current test (I need the text box to contain all received data though).
So far, I've investigated delegates, handling the threads myself, and just began looking into BackgroundWorkers. I tried to use delegates earlier today, but couldn't figure out a way to update the text boxes. Would I need to use a call back function to do this since I can't do it in the body of the delegate function itself? The problem I see with handling threads myself is figuring out how to pass data back and forth between the thread and the rest of the program. BackgroundWorkers, as I said, I just started investigating so I'm not sure what to think about them yet.
I've created a VB Console Application Project and am trying to instantiate a Report Viewer object. To my understanding I need to import Microsoft.Reporting.WinForms however Visual Studio does not recognize this name space. Is there some reference I need to add?
View 4 RepliesI wish to incorporate general expressions in my Visual Basic work.Other than the basic inputting "Imports System.Text.RegularExpressions", I have no idea how to do put general expressions in my VB project.However, I can create the expressions (so, all is not lost).
View 1 RepliesI am making a maze game and I want the cursor to be a different cursor that I made but I'm not sure how to change the cursor without having it hovering over a label or button.
View 7 RepliesThis is going out to the forum at large. Where can I find the most complete explanation of the use of the DataGridView control in VB.Net? Any publication, or on-line reference except MSDN, please. I can never make heads or tales of MSDN.
Likewise, a complete tutorial on the usage of XML within the .Net Framework would be appreciated. Same qualifications as above.
i have a question in VB6 you can make a program to start from a module but in .net i can make it only if i choise it as console application. my question is how can i make it if it is posible. i make in module sub main
Module mdlMainBegin
Public Structure FInfo
Dim InitPage As String
Dim HistoryFilPath As String
[code]....
i successfully deployed one application but some small small issues coming in that...Here i want clarify some common doubts in redistributable components...I created one windows application in VS 2008 with C# as language and SQLServer 2005. I created msi setup application in vs 2008 itself. My application includes 2 third party tools. One is for skin and another is for capture images from different devices like camera, web cam etc...Database i deployed is sqlexpress 2005
Generally i added the following prerequisites:
1. Dot Net Framework 3.5
2. Windows Installer 3.1
3. Crystal Report basic runtime for vs 2008 (x86, x64)
4. SQL Server 2005 Express SP2 (x86)
For all these i have no doubts except 4th one.Other than these prerequisistes my first third party tool(for skin) include Visual C++ 2005 Runtime. For this i tried Visual C++ Runtime included in the VS 2008 prerequisites but not worked. So i downloaded Visual C++ 2005 for x86 and x64 and create the custom prerequisites using "Bootstrapper Manifest Generator" and its working successfully For the second third party ocx component (for live video from devices) they telling the following compenents other than ocx component.
a. MFC Libraries (gdiplus.dll, msvcrt.dll, mfc42.dll)
b. DirectX 9 runtime or better
c. Windows Media format runtime files (they gave wmfdist.exe)
I told the system OS requirement is Windows XP SP2 or Vista. Architecture 32 bit and 64 bit(with conditions)
1. I didnt include the 3 MFC Libraries (gdiplus.dll, msvcrt.dll, mfc42.dll) in my setup application Yes i not included the these dlls. But i didnt get any error up to now. I think XP SP2 included these files. Any problem raises in vista or somthing other machines if i leave these files or these files updated when i installed that Visual C++ 2005 runtime? Because when i search MFC libraries i got the result as visual c++ runtime. Please clear about this and tell the i want to include or not?
2. I didn't include DirectX 9 runtime I dont have any common doubt in this because mostly sp2 inludes directX only. But if i inluded these can you give the latest and best redistribution component download link? I dont know is this component differe 32 bit or 64bit?
3. I didnt include Windows Media format runtime files This also i dint included but not got any issues. But some customer told that grains like coming in the live screen. Is this because of unavailability of these component? For include this i didnt got the download link. But i download the sdk from the following link...
[URL]
I installed and i got the same wmfdist.exe as the third party gave. My doubt here is is this support for vista also .. Any incompatabiliy for 64 bit.? if then can anyone give the 64 bit redistribtuion component download link also.
4. SQL Express 2005 Express 64Bit As this application want to support 64 bit also...i want to include 64 bit express edition. But i think the 64 bit support is express advanced version only. Here my problem is if i download tht i cant create custom prerequisites for sql express because i am not well in this.
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View 14 Replieswhipped up this code real quick which uses a ThreadPool on Form Load to iterate through my subnet and tell me if there's a device communicating at each IP address.
some questions: Why am I able to update BOTH my label at the top AND the listbox, but I'm only using an .Invoke on the Listbox?How can I know how many threads are currently being used while that is executing?
What does the SyncLock do?I'm aware some people don't like the use of Application.DoEvents(). Is it ok to be using it in this instance or is there a better practice?For those wanting to try it out, drag a Label and a Listbox to a new form. Label is called "currentIPTextbox", Listbox is default name.
[Code]...
OK, I have this loop I want to perform which involves the serial port. Not to get too specific I'm actually sending data to an external device within a loop The loop involves a Start number, increments by a Step and ends when it gets to Stop This repeats until I click a STOP button.
View 15 RepliesI have a MustInherit Parent class with two Child classes which Inherit from the Parent.How can I use (or Cast) Me in a Parent function as the the child type of that instance?EDIT: My actual goal is to be able to serialize (BinaryFormatter.Serialize(Stream, Object)) either of my child classes. However, "repeating the code" in each child "seems" wrong.
EDIT2: This is my Serialize function. Where should I implement this function? Copying and pasting to each child doesn't seem right, but casting the parent to a child doesn't seem right either.
[Code]...
I'm making a program to protect custom game files from being copied as best I can, however there are a couple things I need to account for. Some of them I have, others, I have not been able to find information on. When the files are not in use, I have them fully encrypted and hidden from the lay user through a bunch of other tricks (+s attribute, for example). However, I would also like to prevent copying these files while they are being used by the game - obviously I cannot have them encrypted while the game is attempting to read from them.
This opens up a hole, which I have also tried to deal with, but I know my attempts in this regard are less than thorough:
Stop several known well-known copy programs from operating during operation, that being Windows Explorer, Teracopy, and cmd
Now, the other solution I was thinking of was a filesystemwatcher object scanning the better part of the computer for any copies of these files located outside of the "OK" directory, but I'm a bit skeptical as to whether or not this would be very efficient. Any ways to make copying these files difficult without rendering them unusable to the program.
If you have a separately declared PUBLIC INTERFACE and then IMPLEMENT that INTERFACE.
1) My general question: Is an INTERFACE simply a means to ensure that a CLASS implements all the methods defined in an interface and to ensure that they can only be implemented once?
I have noticed that a method that IMPLEMENTS an INTERFACE method can still have overloads though. :-)
If so, when combined with INHERITANCE though I believe I can finally see the use for defining an INTERFACE!!
2) Do you have to use an interface when linking to a VB6 project ( is this via Component Object Model or COM ) and if so, do any attibutes need to be applied when doing so?
Here is a code snippet.
creating a PUBLIC INTERFACE outside of any CLASS. I guess this would not normally be done from an OOP point of view?
Public Class ExampleClass
Implements MyActions
Implements Whatever
[Code]....
I am using VB express 2008.How I can create a General Ledger Style Listview with alternating colourd rows.
View 4 RepliesI have created financial program but i need general regular expression for the formula which I will create it.
View 4 RepliesI plan to use iTextSharp 4.04.0 for my program for creating pdf on the fly.My find out that iTextSharp 4.04.0 is release under license GNU Lesser General Public License (LGPL).I have searched online but can't really undestand what GNU Lesser General Public License (LGPL) is.My question is does the dll which released under GNU Lesser General Public License (LGPL) is free to use? Free to use by the company?
View 1 Repliesurl...I'm working on a simple MP3 player and are stucked on some Treview.Click and Listview.Items.Add problems which I cant seem to get past.What I'm trying to do is first with a button launch a FolderDialog to get folder path, when this is done I add the directories and subdirectories to tvFolders1 (Treview)For the whole procedure for this see classes LoadFolderTree(), LoadDir() and tvFolders1_AfterExpand.This seems to work just fine and no problems as far as I can see The we add a feature where user click on the Treeview (tvFolders1) and we are supposed to do the following: On tvFolders1_AfterSelect (when the user actually select something)I am the trying to add Items and subitems to the lvFiles control (Listview)[code]Now adding items and subbitems goes just fine if I:
1. Do not clear the ListView lvFiles in the Class tvFolders1_AfterSelect But I need that, I want the listview to be cleared before adding new items/subitems or we end up with an enormous list
2. Only add more items to the ListView without doing anything more
If I clear the ListView lvFiles in the class tvFolders1_AfterSelect the application will simply freeze and crash after clicking on any item in TreeView tvFolders1So basically somewhere in my code there is something causing this and that's were I need help, I where hoping someone could figure out what I need to do..I have pasted the whole code for that form because I suspect the problems are not in the adding/clicking on items but somewhere else, I do not know though.There is also a "bug/another big problem" in the adding of items/subitems to the lvFiles ListView and that is that the first mp3 file only gets added with file/path and not ID3.
I understand that there are several ways of Inserting, Updating and Deleting records in a database such as DataAdapters, DataSets, TableAdapters, SqlCommandBuilders, Parameterized SqlCommands, StoredProcedures, etc, etc,etc. According to David Sceppa Sprocs are the most preferred. Ok, I go with him on this one (who am I to challenge him anyway?).
My question is, apart from Sprocs, which of these options is the BEST for a large commercial database application and why, taking performance into account? What are the benefits and drawbacks of each option?
I am writing a program to assist Paramedic students in learning the Drugs that they have to know in order to pass their classes. I have created an Access database to hold all the information on these drugs, but not every student that will use this program will need to learn all the drugs contained within this database.
Right now I have 43 drugs in the database and still growing.
What I want to do is to present to the student the drugs and have them say "Y" or "N" as to whether its on their required list to learn. That way they only work on the ones that they need to.
I've two BGW with similar coding but different approach, My second BGW shows me "NOT RESPONDING" whenever i try move/click/focus to form while the BGW is running.
VB
RichTextBox2.AppendText("Some Text")
process2.ReportProgress(inc)
My.Computer.Network.DownloadFile(andpic, "pics/" & spliti(0) & nnum & ".png")
My.Computer.Network.UploadFile("pics/" & spliti(0) & nnum & ".png", "ftp://ftp.mywebsite.com/domains/mywebsite/public_html/Pics/" & spliti(0) & nnum & ".png", "users", "password")
WebBrowser1.Navigate("Mywebsite")
I've taken out number of things that i think is causing this error Are they the cause of "NOT RESPONDING" ?
To write a effecient Active Directory library to ease the work of technicals who are responsible to create access models into the domain controller's Active Directory. This library must allow the following:Basic operations: Add, Modify, Delete, List entries;An entry may either be an organizational unit, group or user (no further need required as of now);I thought about having a class which would represent the domain with which we want to work with.
public class Domain {
public Domain(string root) {
Root = root;
[code].....
I have a database with three tables:
stock
orders
order_details
Stock and Orders are self explanatory. Order_details is a lookup table, holding basically just the orderID, stockID and quantity for each item in the order. That's not very friendly for the user however, so what I want to show is a DataGridView with some elements from order_details, and some from stock, i.e.:
Part_Code, Item_Name, Description, Quantity, Price
I can create a database view for this easily enough, and bind it to a datagridview. It shows existing items in the order fine, but the problem is the view doesn't update when I add new elements to order_details in the dataset. It appears that it's bound to the main database, and so won't update until I save the record. That also has the problem that it's now much harder to update the database. A simple datagridview bound to order_details would make it easy for the user to enter quantities and for me to save the record, this one now needs a custom update statement.
In summary:
- I want to show data from two tables
- I want the datagridview editable (well, the quantity column anyway)
- I want the datagridview to update when I add entries in the dataset
What is the best/easiest way to do this? Is my current approach of a view in the database and custom update statements sensible? How can I get the datagridview to refresh whenever there's a change to the local dataset?
I recently started a project and needed to do some integration with LDAP via DirectoryServices. I've done this in other apps so I went into one of them to see how I did it -- why reinvent the wheel right? Well, while this wheel works, it was developed years ago and kinda smells (it's wooden, firmly attached to the previous vehicle, hard to repair and produces a potentially bumpy ride).So I thought to myself, this is the perfect time to refactor this puppy and make it more portable, reusable, reliable, easier to configure etc. Now that's fine and dandy, but then I started feeling a tad overwhelmed regarding to where to start. Should it be a separate library? How should it be configured? Should it use IoC? DI?
So my [admittedly subjective] question is this -- given a relatively small, but quite useful class like the one below, what is a good approach to refactoring it? What questions do you ask and how do you decide what to implement or not implement? Where do you draw the line regarding configuration flexibility? [Note: Please don't bash this code too much okay? It was written a long time ago and has functioned perfectly well baked into an in house application.]
Public Shared Function AuthenticateUser(ByVal id As String, ByVal password As String) As Boolean
Dim path As String = GetUserPath(id)
[code]......
I'm working on a system where there can be 2 level of users "Admin" or "Researcher".We have the requirement to allow the researcher to change fields for a record a record, but they want the original values to stay in the record and have an admin "accept" or "approve" the changes before the real record gets updated.Has anyone run into this scenario before? I'm trying to think of the best way to do this.
View 3 RepliesTrying to implement a recordset approach in VB.NET and have gotten to the point where things almost run. :)
Code:
Dim strSQL As String
Dim rsMaster As New ADODB.Recordset
strSQL = "select * " & "from tblDQ " & "order by xid, xcode, xDOS"
[Code].....
I'm currently working on a system that requires monthly, quarterly and annual reports. I have no problem in generating/retrieving the data, my problem is the presentation. What is the best way to do it? I need the report to be:
View 3 RepliesI have a wierd problem with threading in an ASP.NET application. For some reason, when I run the code in the request thread, everything works as expected. But when I run it in a separate thread, nothing happens.This is verified by calling the below handler with the three flags "on", "off" and "larma" respectively - in the two first cases everything works, but in the latter nothing happens.[code]
View 4 Replies