dotConnect for SQLite Frequently Asked Questions
What is the difference between the Standard and Professional
The free Standard Edition represents a fully-featured ADO.NET data provider with
design time support and advanced classes. The Professional Edition adds more classes,
tools, technologies, and integration capabilities. The following list briefly enumerates
main advantages of Professional Edition.
- Entity Framework support allows you to employ the latest conceptual technology
- The LinqConnect support allows you to focus on objects instead of relational
data in database application development.
- The SQLiteDump class serves to store a database or its parts as a script and
to restore database from the generated script.
- The DataLink class serves for universal cross-form data binding.
- The powerful SQLiteDataTable component as all-in-one table data access solution.
- The SQLiteDataSet class allows using typed and untyped provider-specific datasets.
- DataSet Wizard greatly simplifies process of generating datasets in your
- DataSet Manager and DataSet Editor help managing the datasets.
- Support for dbMonitor that performs per-component tracing of database events
such as SQL statement execution, commit, rollback, etc.
- Enterprise Library support allows you to take advantage of Data Access
Application Block functionality.
- ASP.NET 2.0 providers support allows using the data provider in ASP.NET
2.0 provider model.
- Sync Framework support allows using dotConnect for SQLite for synchronizing
SQLite data with other data sources.
To test this functionality use the Trial Edition, which incorporates all aforementioned
Installation and deployment
I installed dotConnect for SQLite trial, then I have bought
and installed purchased version, but something went wrong.
Make sure you had uninstalled the trial version correctly. There should be no old
(trial) assemblies present in your system. Uninstall dotConnect for SQLite and check
your Global Assembly Cache and local folders for Devart.* assemblies. Remove all
Devart.* files and reinstall dotConnect for SQLite.
How do I upgrade to a newer version of dotConnect for SQLite?
Close all running IDEs and help collections, then run the installation package of
the newer version. You will be prompted to uninstall the previous version; agree
and then proceed to installing the newer build.
You say, there are sample projects, but I can't find any.
Probably you installed dotConnect for SQLite not in typical mode. Please choose
typical when installing dotConnect for SQLite. All samples are installed
by default in \Program Files\Devart\dotConnect\SQLite\Samples folder.
Are there any restrictions for Visual Studio Express editions?
Yes, there are some. First, the provider add-in (and hence menu item) is not available.
Second, components are not registered in toolbox automatically (though you can do
it manually). Finally, advanced Visual Studio integration (DDEX)
is not available, except Microsoft Web Developer Express 2008 and 2010.
How do I deploy my application?
To deploy an application written with dotConnect for SQLite, you need to:
- deploy the Devart runtime assemblies used by your application;
- include the technical license resource;
- in case your application uses provider factories, you also need to expose dotConnect
for SQLite to the system.
For the detailed description of each of these steps, please refer to the
Licensing topics in dotConnect for SQLite help.
How to install dotConnect for SQLite on a machine that does
not have Visual Studio or Delphi installed?
Select the "Minimal" type when asked by the installer.
How do I upgrade my projects from dotConnect for SQLite 1.xx?
In this release there were some important name changes in the product. Particularly,
assemblies, namespaces, invariant name, and some types were changed as follows:
"CoreLab.Data" became "Devart.Data";
"CoreLab.SQLite" became "Devart.Data.SQLite";
"SQLiteDirectFactory" became "SQLiteProviderFactory";
Invariant name became "Devart.Data.SQLite";
Your projects must be updated to be compatible with dotConnect for SQLite 2.0. Here
is the list of files you should update:
*.csproj, *.vbproj - references to assemblies
*.cs, *.vb - namespaces
*.licx - namespaces and assembly names
Web.config - assembly names and web provider types
This is done automatically when you invoke the Upgrade wizard from Visual Studio
menu: Tools | SQLite | Upgrade Wizard.
I have received a message that Devart.Data is incompatible...
Devart data providers use a common assembly (Devart.Data.dll), so it is necessary
to install compatible providers versions. We release our ADO.NET data providers
in a single pack, thus releases from the same date should be compatible. Also, Devart
data providers should warn you before installation if an incompatible version of
Devart.Data.dll was detected.
I can not open database file... What am I to do?
Maybe the sqlite3.dll file is missing. You should make sure your system has
acces to this file by checking if it is available in the folder with the database
or in the \WINDOWS\system32\ folder.
Can I use the sqlite3.dll downloaded from SQLite homepage?
sqlite3.dll included with the dotConnect to SQLite is compiled with SQLITE_ENABLE_COLUMN_METADATA
defined. It allows using sqlite3_column_database_name, sqlite3_column_table_name,
and sqlite3_column_origin_name functions, which are necessary for building correct
DML statements for a result set with aliases used. If you want to use SQLite from
its official website, you need to download its sources and compile it with SQLITE_ENABLE_COLUMN_METADATA
I have received the following message - "error 0175:
The specified store provider cannot be found in the configuration, or is not valid..".
What does it mean and what should I do?
You should put the Devart.Data, Devart.Data.SQLite, and Devart.Data.SQLite.Entity.EF<Version>
assemblies in the Bin folder of your application (or place these assemblies in Global
Assembly Cache). The <Version> here is the version of Entity Framework used
in your application. For Entity Framework v1 the assembly is called
Devart.Data.SQLite.Entity.EF1.dll, for Entity Framework v4 and v5 it is
Devart.Data.SQLite.Entity.EF4.dll, for Entity Framework v6 it is
Devart.Data.SQLite.Entity.EF6.dll. For Entity Framework Core it is
Devart.Data.SQLite.Entity.EFCore.dll. Make sure that your application is licensed
correctly (take a look
at the Licensing
article for more information).
Information about provider registering is available in the
Subscriptions and Upgrades
What are the benefits of the dotConnect for SQLite Subscription
The dotConnect for SQLite Subscription Program
is an annual maintenance and support service for dotConnect for SQLite users.
Users with a valid dotConnect for SQLite Subscription get the following benefits:
- Access to new versions of dotConnect for SQLite when they are released
- Access to all dotConnect for SQLite updates and bug fixes
- Product support through the dotConnect for SQLite Priority Support program
- Notification of new product versions
Priority Support is an advanced product support program which offers you
expedited individual assistance with dotConnect for SQLite-related questions from
the dotConnect for SQLite developers themselves. Priority Support is carried out
over email and has a two business day response policy.
Can I use my version of dotConnect for SQLite after my Subscription
Yes, you can. dotConnect for SQLite version licenses are perpetual.
Do I need a new subscription to use dotConnect for SQLite 5?
No, you don't. Provided that you have an active subscription, you will be able to
download dotConnect for SQLite 5 from Customer Portal.
What is the licensing you use?
dotConnect for SQLite uses .NET component licensing. To build operational application
dotConnect for SQLite requires valid license. If no license is available, dotConnect
for SQLite does not work.
How to embed license into my application?
Usually you do not have to care about embedding license in your application. When
you install dotConnect for SQLite the system is configured so that licensing is
done transparently. License is automatically added to project when you place a SQLiteConnection
component onto a form.
In some cases you have to manually add license. It is necessary for console applications,
class libraries, and some ASP.NET applications. For instructions on how to add license
manually refer to
Licensing topic in dotConnect for SQLite help.
On opening connection I get an exception saying "License not
found...". What should I do?
This generally indicates that license information could not be found, or you try
to apply it in some way that does not suit the kind of application. For example:
- File licenses.licx, required for dotConnect for SQLite to function properly,
could not be found.
- File licenses.licx is not added as embedded resource.
- File App_Licenses.dll not found in ASP.NET applications.
To fix the problem determine type of your application and read corresponding section
of "Licensing" topic.
On opening connection I get an exception saying "License not
valid...". What should I do?
This means that license information was found but it is incorrect. It usually happens
in the following cases:
- The project was earlier compiled with old or trial version of dotConnect for SQLite.
- File licenses.config used by a class library does not refer to launched
- The App_Licenses.dll belongs to other application or needs to be recompiled.
- Something's wrong with the operating system or installation of dotConnect for
If you encounter one of these problems, do the following (the numbers of actions
correspond to the numbers of the problems in the above list):
- Delete all files from the bin and obj folders and rebuild the project.
- Specify the executable in the licenses.config file.
- Rebuild App_Licenses.dll for the current application.
- Perform the following steps:
- uninstall dotConnect for SQLite;
- remove all Devart.* and policy.*.Devart.* files from the GAC;
- clear the Program Files\Devart\dotConnect and Program Files\Common Files\Devart\dotConnect
- re-install dotConnect for SQLite.
Deployed application worked fine some time, but in some moment
it started to say "Sorry, your trial period has expired". But I do not use trial
version any more.
Probably you compiled the application with Trial edition of dotConnect for SQLite,
and deployed it with assemblies from non-trial version. In this case time limit
is actual as well. To eliminate the problem just recompile the project.
How to license ASP.NET applications?
To support server-side compilation you ought to have special assembly App_Licenses.dll
in the Bin directory of your site. To create this assembly execute Build
Runtime Licenses command in the licenses.licx file context menu in the Solution
Explorer view. Required assembly will be created automatically.
Note that this is not necessary for precompiled ASP.NET applications (if nothing
is compiled on server by user request). Precompiled applications are licensed as
How to make dotConnect for SQLite work with SQL Server 2008
Business Intelligence Solutions?
To do this install dotConnect for SQLite on same computer where SQL Server 2008
I am having problems with the licensing in my project... What
am I to do?
If any problems with licensing occurred in your project, you should use the License
Information dialog to resolve them. You can access it from the Visual Studio menu:
Tools | SQLite | License Information.
Do end-users need a license?
No, end-users of your application do not require any license.
I call SQLiteConnection.Open(), then Close(). The database
file is still locked by my application. Isn't it a bug?
No, it is not. This is Connection Pooling feature. Actual connection is not closed
in order to be used later by your application. This boosts performance greatly.
I get exception "Timeout expired. The timeout period elapsed..."
What to do?
The full text of the exception is "Timeout expired. The timeout period elapsed prior
to obtaining a connection from the pool. This may have occurred because all pooled
connections were in use and max pool size was reached." It clearly states that you
have run out of connections available. To solve the problem increase Max Pool Sizeconnection
string parameter value. The default value is 100. Another way to get extra connections
is to clear one or all of the pools. Or you can turn connection pooling off using
Pooling connection string parameter.
How to prevent possible pooling problems?
You can clear the pool explicitly. Generally pool is cleared automatically when
connections are idle or closed by the server. To force the operation call ClearPool
or ClearAllPools methods. Another solution is to disable the pool at all (set Pooling=false
in connection string). If this does not help, the problem is not caused by pooling.
How to open documentation on dotConnect for SQLite?
There are several ways to open dotConnect for SQLite documentation:
- Use appropriate shortcut in start menu, for instance, Start - Programs - Devart
dotConnect for SQLite - Documentation.
- Use command in the IDE: Tools - SQLite - dotConnect for SQLite Help.
- Position cursor on some class from Devart.Data.SQLite and press F1.
There is also same documentation in chm format. You can download it from our site
at the following address:
I can't see the documentation in Visual Studio Help Collection.
Correctly installed documentation appears as separate node in combined collection
of Visual Studio and Delphi. If you can't find dotConnect for SQLite node
there it is because you enabled topics filtering. To reveal the node set filter
to "Devart Documentation", or "(unfiltered)", or "Visual C#"
Another possible reason is that you installed some IDE after installation of dotConnect
for SQLite. In this case use aforementioned methods to reach documentation.
All topics in CHM file are blank.
This can happen due to some patches from Microsoft installed on your system. Please
read this page to
find possible solutions for the problem. In most cases it is enough to right-click
on the CHM file, select Properties, click on the "Unblock" button and click "Apply"
to show the contents.
Are LINQ to SQLite and Entity Framework supported?
The Professional Edition of dotConnect for SQLite supports both LinqConnect (formerly
called LINQ to SQLite) and the latest version of ADO.NET Entity Framework.
Where do I start with Entity Framework or LinqConnect?
For your convenience there are brief tutorials that you can use to get acquainted
with the technologies:
Are there any demo projects to play with?
Yes, dotConnect for SQLite includes several Entity Framework and LinqConnect samples
in C# and Visual Basic. The samples demonstrate how to use several entities and
a relationship between them. You can also download separate
Entity Framework Query Samples package, which is a standard Microsoft demo
with added SQLite connectivity.
I get concurrency error when modifying records using SQLiteDataAdapter
or SQLiteDataTable. What can be wrong?
This can happen when SQLiteCommandBuilder generates a query without primary key
field. To avoid it use custom update command instead of generated by SQLiteCommandBuilder.
This problem should not take place if primary key field participates in SELECT statement.
No components can be found in the toolbox.
This can happen if the installation encountered some problems. You can add the components
to toolbox manually. This procedure is described in the
article in the documentation. Note that Microsoft Web Developer 2008 Express edition
does not allow working with toolbox at all.
dotConnect for SQLite components in Visual Studio 2008 are
Make sure you're in Component Designer view. Do not confuse with Designer
view. To switch between views use context menu of .aspx file in Solution Explorer.
This relates to Web projects only.
SQL Server Integration Service (SSIS) can't get the list of
tables in my SQLite database.
This is an architecture limitation from Microsoft, SSIS understands metadata of
SQL Server only. To circumvent this you have to write queries manually.
Can I use dotConnect for SQLite assemblies in the x64 process?
dotConnect for SQLite assemblies are built with the /platform:anycpu option. So,
you can use provider's assemblies on any platform (x86 or x64). For more information,
refer to https://msdn.microsoft.com/en-us/library/zekwfyz4.aspx
However, you need to ensure that you are using the compatible version of the engine
library sqlite3.dll. The engine library version of the proper capacity is deployed
during installation of dotConnect for SQLite depending on the target machine capacitity
(e.g., the 64-bit version is deployed onto 64-bit machines).