I am writing a small library that all it does is opens a connection with the local SqliteDb present just near the application and reads from the database depending on the search query.
The one using this library does not need the access to Insert or update any record but are updated from lets say me.
SO to create a database i use this:
SqlConnection = new SQLiteConnection("Data Source=Languages.db;Version=3;New=True;Compress=True");
Than to access the database the same but New=False
Now i am using Firefox Sqlite Manager to modify the table such as creating the structure and adding values.
But when i save the file with firefox i get an error on C# stating that it is write/read protected when i try to open the connection!!
Edit: I also tried to use Sqlite Browser: http://sqlitebrowser.org
but then i got that unsupported file format!
Am i missing something?
Regards
The FireFox SQL Lite Manager when open, restricts other applications from making a connection to the SQL Lite database. If you shut down the FireFox Manager, your C# code will execute correctly.
You can refer this answer to understand the nature of the lock applied by Firefox Firefox locks places.sqlite
I have noticed that when creating a table or altering the table somehow from the SQL manager gui, the gui itself creates some headers/meta data that the driver is not able to read and thus it flags it as corrupted.
To solve the issue all i had to do is create the tables and alter as necessary from my application directly,than i can add records using the firefox manager and it seems to be working correctly!
Correct me if im wrong!
Related
A little background first: I need to extract a database from an SQLite dll file for my client who has burned bridges with the previous dev.
I have these 4 files sitting on my desktop:
System.data.SQLite.Linq.dll
System.data.SQLite.dll
SQLite.Interop.dll
Payroll.exe
I am also given the password for the SQLite DB which Payroll.exe uses to interact with the database. With this is it possible for me to dump an SQL file (so I can work with something familiar)?
Major problem is that I have no experience with C#, .NET stuff and DLL files (I know it stands for Dynamic Link Library!)
I'm willing to dabble and learn some C# to do this.
As suggested, I decompiled the source and found some interesting code:
namespace Payroll
{
internal class Payroll_Database
{
private static string ConnectionStr = "Data Source=.\\System.Data.SQLite.Linq.dll; Password=******!";
private static SQLiteConnection Connection = new SQLiteConnection();
It seems certain that System.Data.SQLite.Linq.dll is the database file. I have trouble opening it with tools such as SQLite Browser. I have tried renaming it to a .db, but again no dice.
Your database won't be in the dll and exe files you list.
It should be in a separate file, possibly with an extension like .sqlite, .sqlite3, .sdb3 .db or .db3 (but this is not mandated).
If you can locate the db file, you can open it with any sqlite client (e.g. you can use the firefox sqlite-manager plugin), and extract the data as required.
You could probably find the database filename from the Payroll.exe source code, which you can read by opening Payroll.exe in ILSpy.
If you cannot locate the db file, you will be unable to retrieve the data. In which case, the best you can achieve with the files you list would be to determine the database schema by reading the payroll application's source code.
Update:
Now you've found the connection string, it looks possible that the database could indeed be the System.Data.SQLite.Linq.dll file, and the developer has given it a name to match a known .NET assembly as some kind of security through obscurity.
If that is indeed the db file you should be able to open it directly in a SQLite client application like the firefox sqlite-manager plugin I mentioned above. If you can't open it in a SQLite client application, then you can to check to see if it is a .NET assembly after all by opening it with ILSpy or Microsoft's MSIL disassmebler.
Update 2:
According to this SO question, you should be able to open your encrypted db file with the free SQLite2009 Pro Enterprise Manager.
I am using SQL server 2008 R2 and VS2010. I made simple application by using this tools. I attach database as .mdf in my application and deploy that application on other machine its works fine. Now if I plan for new release of my app which some extended features, I can upload Code by DLL, But problem is updating .mdf file, to handle this I am exporting database into .xls sheets (Application have one utility to backup database) and then import into SQL Server to create new .mdf file. Someone have better solution on this? Can I open old version of .mdf file in SQL Server(Third party software) and Execute DML/DDL script on it to make latest code and database compatible ? May I keep .sql file in one of my project code and execute it by some utility..? Any Class in C# which can handle this..?
I did not get your query completely. Do you want to upgrade the DB through the application?
You can of course run .sql files through your application, but I'm not sure it would help you change the Database configuration.
Alternatively, if you already have the updated .mdf file and the database name is same, then you can follow the following steps.
1. Detach the database by SSMS in the third party environment through SSMS.
2. Replace the .mdf, .ldf and .ndf (if any) in the disk.
3. Attach the updated .mdf file.
This will get the new Object definitions as well as data.
As far as I'm aware, there is no process for merging .mdf files, because the SQL Server might not be able to identify the similar objects properly as sys tables may be different, and also would not know which data to keep in the final data base, in case the table structure, constraints or data conflicts occur.
However, looking at your requirement, the best way I can suggest is,
1. Generate the Alter scripts for the tables modified (By right clicking on the object name and using Script Table As.. option). Of course, I assume you have the list of objects modified and the modifications.
2. Connect the two DB servers over network and write an SSIS package or Import data from the old DB to the new one for the tables you want.
Hope this helps.
I have a weird problem with my local database. I added it as a .mdf file, and created 2 tables in it.
I tested the connection and the message box states that the connection is working properly.
The problem appears when I try to insert data into that database from my C# application. I tried 2 different ways:
By using SqlCommand.ExecuteNonQuery("INSERT INTO ....")
By using .dbml file (Linq-to-SQL) datacontext
When I try to insert data, no error is thrown, but no data is inserted into the database either. What could be the problem?
I'm using C# in VS 2010 and SQL Server 2005 to make my application
most perceived problems with MDF files tend to boil down to one of:
what file have I actually opened?
is my build/run process actually copying over that file every time I run the application?
do I have gratuitous error-handling that is swallowing an exception?
Check your connection string, and look in the execution folder (not the project folder), until you are very sure which file is being opened. It should get updated after your work (make sure you dispose the connection etc properly).
Also: try fetching the data in a new data-context immediately after the insert, so see if it made it in or not.
My aim is to backup a database (.mdf) as one file with my web application project written in C#.
The backup should later on be loaded on a "restore"-page, where the data in the backed-up tables could be appended to the original database row by row.
What would be a good practice to implement this?
I thought of just copying the mdf file, but then I read about attaching and detaching of the database. Furthermore I don't know what to do with the _log.ldf file.
I'm looking forward to your hints. Thank you in advance for your help!
EDIT: I can only use the free SQL Server Express for this, because I want to distribute my program to other people.
Probably, you refer to the Backup and Restore using C# for Sql Server to get a complete idea about writting a code in C#, which has helped me a lot when I was using it.
By the use of Backup class in C#, you can get all the facilities to backup as well as restore.
If you are only interested in appending the data rowwise afterwards, perhaps it is easier to export each table to CSV and import it afterwards (so you have rowwwise control in C#).
If you insist ine one file, just add all the CSV's to a zip.
You can use the FileHelpers library for this (http://www.filehelpers.com/) and you will have it up&running in no time.
Apparently there is a Backup class in the SQL Server Management Objects library.
You might want to check that out first, as it doesn't look overly complicated:
http://msdn.microsoft.com/en-us/library/microsoft.sqlserver.management.smo.backup.aspx
It would require you to have two or three libraries installed on the server you run it on, though they are fairly small - not Windows SDK sized...
pls go through this link on how to backup data and restore using c# and sql server .In addition to you have to add these names spaces
Microsoft.SqlServer.Management.Smo;
Microsoft.SqlServer.Management.Common;
Hey folks,
I'm developing a small console app, that should parse text and place data to an SQLite db, app written in C# 3.5 + Entity Framework to persist data to the SQLite. Everything works fine expect that fact that after app did its job I can't find data in the SQLite file. During app running I can persist and read data from db but when it's done I open db in SQLite Administrator (http://sqliteadmin.orbmu2k.de/) and found no data.
Does anybody know what's wrong? Thank you.
Are you sure you're not configuring your SqLiteConnection to use an in-memory database, or a temp file in the user store? SqLite can set up a database almost anywhere, for almost any length of time, and its default behavior may not be what you expect.
So silly from my side, app after deploying to the bin folder copied db file there as well and manipulated with that db file, data is there.