dotConnect for SQL Server 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.
- The powerful SqlDataTable component as all-in-one table data access solution.
- The SqlDataSet 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.
- The DataLink class serves for universal cross-form data binding.
- The SqlLoader class serves to load external data into the database extremely
- Support for dbMonitor that performs per-component tracing of database events
such as SQL statement execution, commit, rollback, etc.
- ASP.NET 2.0 providers support allows using dotConnect for SQL Server in
ASP.NET 2.0 provider model.
To test this functionality use the Trial Edition, which incorporates all aforementioned
Installation and Deployment
I installed dotConnect for SQL Server 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 SQL Server and
check your Global Assembly Cache and local folders for Devart.* assemblies. Remove
all Devart.* files and reinstall dotConnect for SQL Server.
How do I upgrade to a newer version of dotConnect for SQL
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 have installed dotConnect for SQL Server not in typical mode. Please
choose typical when installing dotConnect for SQL Server. All samples are
installed by default in \Program Files\Devart\dotConnect\SQL Server\Samples
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 SQL Server, 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 SQL Server to the system.
For the detailed description of each of these steps, please refer to the
Licensing topics in dotConnect for SQL Server help.
How to install dotConnect for SQL Server on machine that does
not have Visual Studio or Delphi installed?
Choose "Minimal" type when asked by the installer.
How to deploy web projects that use dotConnect for SQL Server?
Place Devart.Data.SqlServer.dll and Devart.Data.dll in bin folder of your
web project. Depending on the type of your project, you may also need the Devart.Data.SqlServer.Web.dll
file. Another way to install the *.dll files needed is to launch setup program of
dotConnect for SQL Server on a target machine and choose "Minimal" option.
How do I upgrade my projects from dotConnect for SQL Server
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.SqlDirect" became "Devart.Data.SqlServer";
"SqlDirectFactory" became "SqlServerProviderFactory";
Invariant name became "Devart.Data.SqlServer";
Your projects must be updated to be compatible with dotConnect for SQL Server 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 | SQL Server | 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.
Subscriptions and Upgrades
I have a registered version of dotConnect for SQL Server.
Will I need to pay to upgrade to future versions?
All upgrades to future versions are free for users with an active dotConnect for
SQL Server Subscription.
What are the benefits of the dotConnect for SQL Server Subscription
The dotConnect for SQL Server Subscription Program
is an annual maintenance and support service for dotConnect for SQL Server users.
Users with a valid dotConnect for SQL Server Subscription get the following benefits:
- Access to new versions of dotConnect for SQL Server when they are released
- Access to all dotConnect for SQL Server updates and bug fixes
- Product support through the dotConnect for SQL Server 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 SQL Server-related questions
from the dotConnect for SQL Server 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 SQL Server after my
Yes, you can. dotConnect for SQL Server version licenses are perpetual.
What is the licensing you use?
dotConnect for SQL Server uses .NET component licensing. To build operational application
dotConnect for SQL Server requires valid license. If no license is available, dotConnect
for SQL Server does not work.
How to embed license into my application?
Usually you do not have to care about embedding license into your application. When
you install dotConnect for SQL Server the system is configured so that licensing
is done transparently. License is automatically added to project when you place
a SqlConnection component onto a form.
In some cases you have to manually add license. It is necessary for console applications,
class libraries, some ASP.NET applications. For instructions on how to add license
manually refer to Licensing topic in dotConnect
for SQL Server 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 SQL Server 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 SQL
- 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 SQL Server;
- 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 SQL Server.
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 SQL Server,
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
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 by selecting License Information
from the SQL Server submenu of the Tools menu.
Do end-users need a license?
No, end-users of your application do not require any license.
I call SqlConnection.Open(), then Close(). Physical connection
is still visible by server. 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 Size
connection 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 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 SQL Server?
There are several ways to open dotConnect for SQL Server documentation:
- Use appropriate shortcut in start menu, for instance, Start - Programs - Devart
dotConnect for SQL Server - Documentation.
- Use command in the IDE: Tools - SQL Server - dotConnect for SQL Server Help.
- Position cursor on some class from Devart.Data.SqlServer 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 SQL Server
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 SQL Server. 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.
How to obtain autogenerated value of autoincrement field after
There are several ways to do it:
- Execute SELECT @@IDENTITY statement.
I get concurrency error when modifying records using SqlDataAdapter
or SqlDataTable. What can be wrong?
This can happen when SqlCommandBuilder generates a query without primary key field.
To avoid it use custom update command instead of generated by SqlCommandBuilder.
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 Installation article
in the documentation. Note that Microsoft Web Developer 2008 Express edition does
not allow working with windows components at all.
dotConnect for SQL Server components in Visual Studio 2008
or in Visual Web Developer are grey...
This relates to Web projects only. 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.
Can I use dotConnect for SQL Server assemblies in the x64