How do I read and write a file using a file format which is readable by a database server, in vb2008?
I have very little experience working with databases, and I can't seem to find any tutorials which don't involve some type of server as a middle-man.
It's really going to depend on which type of database files you are working with. If you have an Access Database file, you can open a connection to the database with the following code.
Dim DBConn as New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=C:\MyDBFile.mdb;")
If you don't want a server, use SQLite. There are .NET bindings that work quite nicely.
Reading and writing the raw database files would be an immense undertaking -- if you have to ask how to do it, you shouldn't. It requires so much work that it's not even worth considering for a moment.
In general, most database-aware software writes to the database using a software library adapter. Like ODBC.
What you might be looking for is the file format that a bulk loader can understand. Something like this (MySQL example).
Related
Our current system database system is a clipper DOS application. The database inside its folder is fragmented/divided into many parts. I want to decrypt the database so that I will have only one database in all and avoid reshuffling of data. I'll attached the file folder Screenshot.. the database is on .DBF format
VScreenshot of files
Often you can decompile the CLIPPER exe file to source code and work from the .prg I've done it many times. The program to use is called WALKYRIE.
In Clipper and Fox Pro for DOS .dbf file is a simple table file.
If You want to use as data base with many tables in one unit.
You can import these tables in MS SQL data base and/or part of a MS Access database.
I see that you got several answers. Most are partially right. Let's address these one at a time:
All those files essentially comprise the "database" for the application you're using. They could be used by other applications as well. Besides having a lot of files, what is the problem you're trying to solve?
People mentioned indexes. You can generally ignore these. There are there primarily to make access to the data files faster. Any properly written clipper application will recreate these if they're missing or corrupted. You could test this by renaming one, running the app, and seeing what happens. If it doesn't recreate it you can name it back. Not replacing missing index files would be unusual behavior.
The DBF file format is binary, but barely. Most of what's in a DBF is text and is readable with an editor. But there's no reason to do so - I'm sure there are several free DBF utilities out there to to read DBF files. Getting the structure of the files could be very helpful.
Getting the data out of the files would also be fairly simple with a utility. If you look up the DBF format you could even write one fairly easily in Clipper, any other language that uses DBF files, or in something like Python. Any language that can open and write files, really. It's not hard - any competent developer could do this in a matter of hours. Must less if you're using Clipper or another language that natively reads DBX files.
Most people create dBase/Clipper programs with relational data, like SQL Server. Where SQL Server has tables that relate to each other dBase/Clipper has a file for each "table." This isn't a requirement, but it was almost certainly done this way.
Given that, if you get the table structures through a utility or by reading the headers in an editor (don't save them from an editor!) you could quite likely recreate the database schema (i.e. the map of the data). Once you have that it's fairly trivial to get the data into another type of database (SQL Sever, Access, or whatever you like to use.) If non of the files are too large it's conceivable to put all the files into Excel sheets. It really depends on what you want to do with it.
As others have said, you may be able to get the code by Valkyrie. Some people have used it very successfully. I don't know where you get it and I've never used it. Why do you not have the code? If this is a commercial application you likely should not have it. If it's a custom app who ever wrote it or paid to have it written should have the code.
Again, it's not clear to me what problem you're trying to solve. But there are many options for doing something with those DBF files. Fortunately they are one of the easier to read data formats you could be working with.
Let me know if you have any questions. Apologies for the typos that are no doubt scattered throughout this reply.
You sort of can get an idea of how they relate to each other by opening the index files they use (.NTX files). If you have the DBU utility (executable) around, you can open the DBF and load the index (NTX). LibreOffice Calc is also able to open DBFs (haven't tested .NTX).
If you open the .NTX on a text editor you will see the indexes in the beginning.
I open with Access, but I can save the data using a PrintFill Program.
I've been trying to create a program that creates a database, creates tables, stores information in these tables, and reads off these tables. I am using delphi and microsoft access (although I am open to using another database program if one is easier to learn). Anyway, I cam across this question and answer: Delphi 7: ADO, need basic coding example
However I am confused about what my connection string would be or how to know what is is. I want the database saved in the same file area as where my program is so would it just be the file directory to that area such as:
FILE NAME=E:\project\Debug\Win32\Studentdb.accdb
Also the user uses +database. If my database name is Studentdb would I just put 'Brill1' in that space or not?
Also do I need to use ODBC connector if I am not using MYSQL? I am guessing not but do I need to use something else. Also, while saving files from microsoft access they save as .accdb however when I created a ADOConnection component on my form and pressed into the connection string property it was asking for a .udl and I haven't run across this anywhere before so I am wondering if I need to convert or do something with that.
I am a real beginner with this so I am sorry if my questions are obvious but I would really appreciate some help or pointed to a beginner's friendly resource on the subject. Thank you.
All possible connection strings from Access 2007 are here:
https://www.connectionstrings.com/access-2007/
...which one to choose depends on which driver you have and/or want to use.
(ACE, OLE, ODBC ...)
I hope someone have already faced an issue to verify that application shows correct data from database. I reviewd how groovy used SQL, but I have no idea where and how I should do that. I'm just starting to use gradle+Spock+Geb for testing application. I have a few files where I described a couple of pages from application, a couple of modules and a file with spock specification. Where and how I need to connect to Oracle DB, use SQL and compare result's data with application's ones?
P.S. I write everything in notepad++ and launch from command line writing 'gradlew firefoxTest'. Does exist any more comfortable way to work with gradle+spock+geb?
Thanks in advance.
Because there are no other answers, I wanted to provide a solution someone at my company thought of. This assumes you already have a project that uses some sort of JDBC. In our case it is JDBI.
The idea is to extend Classloader and then use that to directly access the data access object class via the JVM. That idea should work.
I have not tested it out because it doesn't completely fit our use-case. I'll admit that this does not completely apply to your use case, but technically you could just run the jar of an existing project, which can access the database.
Ok, I know this has been asked a thousand times before, but no conclusive solution has been derived...so here is another really silly question!
I have a Winforms 3.5 app and using LINQ to SQL, hence the Connection string is ALWAYS stored in "app.config" by default (and VS2008 will not accept any other way of storing this - Ive even tried overwriting this in the IDE-generated code). That being said, any person with a bit of computer know-how needs to just browse to the install directory of the app, look for the [appname].exe.config file, and open it to reveal the supposed secure username/password for accessing the database. Even if you opt to encrypt/decrypt this section, it is only done when the app is running - so Im assuming that when the app is closed, the connString section reverts to plain text....that can be once again read. (....how do you win?!?!)
Keeping in mind that Im using LINQ and generating a LinqDataContext, what I would like to know is this:
Can the connstring not be stored elsewhere besides the app.config? (perhaps like in a user setting file that can be modified after installation)
If the above is possible, can I not store a pre-encrypted connstring into the config file (that certainly wont be able to be read) and in my application, opt only to decrypt the connstring whenever the connection is opened?
If none of this is possible, I may have to revert to using traditional ADO.NET (seeing that I already have hundreds of stored procs for all CRUD operations) - at least that way I can have control over how and where the connstring is stored.
BTW - sorry if this is a juvenile/confusing question to ask, and if you feel that Im wrong with anything Im explaining please let me know.
Much thanks!
You can store a pre-encrypted conn-string in the app.config, but i guess it will be useless since, your application sooner or later will decrypt the conn-string (And the plain text will be availiable to anyone interested!)
So you should obtain an SSL cerificate too... (Not a self signed one)
I am developing a software with vb6.0 :( .
I wanna to know that what the best code for saving a file in SQL server and then reading from it is?
I should say that I use ADODB.Stream when saving file.....
what is you suggestion?
Do you need to save to sql. An alternative, and IMO better solution is to save the docs to a folder on your regular file system and save the reference to it in sql.
Unless you have specific reason for wanting to save in sql?
Is there a specific reason you need to use vb6. Legacy?
Here is an example in .NET on achieving what you require, it should be pretty straightforward to convert to VB6
http://www.jstawski.com/archive/2007/05/17/save-documents-with-sql-server-and-display-them.aspx
UPDATE: With VB6 an example using ADODB.Stream to store and retrieve images, which should be similar to what you need:
http://www.devx.com/tips/Tip/14246