The implementation consisted of including the necessary security imperative asserts so the CLR allows our code to perform the operations where it needs permission to perform.

The permissions that we needed were:

- System.Net.SocketPermission

- System.Security.Permissions.ReflectionPermission

- System.Net.DnsPermission 

- System.Security.Permissions.SecurityPermission 

Starting from 6.5 you can use the Connector/Net library inside any medium-trust level environment with out any issue.  You should note that the hosting provider will need to install our library in the GAC however they can avoid granting permissions globally by using the new MySqlClientPermission class in the trust policies.

Let's put some code together to see it working.

For this little application you need to have  MySQL server up an running and enable it to use pipe connections. To do so you need to add the -enable-named-pipe option on the command line. (If you need more information about this please see http://dev.mysql.com/doc/refman/5.5/en/windows-installation.html).

 1 - Create a simple web application using VS 2010

 2 - Add the reference in your application for our library. 

 3 - Edit your web.config file so your application run using a Medium trust level.

<system.web>

    <trust level="Medium"/>

 </system.web>

 4.  Add the MySql.Data.MySqlClient namespace to your server-code page.

 5. Define the connection string:

MySqlConnectionStringBuilder myconnString = new MySqlConnectionStringBuilder("server=localhost;User Id=root;database=test;"   );

          myconnString.PipeName = "MySQL55";

          myconnString.ConnectionProtocol = MySqlConnectionProtocol.Pipe;

6. Define the MySqlConnection to use:

          MySqlConnection myconn = new MySqlConnection(myconnString.ConnectionString);

          myconn.Open();

7. Retrieve some data from your tables: 

MySqlCommand cmd = new MySqlCommand("Select * from products", myconn);

MySqlDataAdapter da = new MySqlDataAdapter(cmd);

DataSet1 tds = new DataSet1();

da.Fill(tds, tds.Tables[0].TableName);

GridView1.DataSource = tds;

GridView1.DataBind();

myconn.Close()

Noticed that you don't need to add any special code so your application can run properly inside Medium-Trust. 

Now you should be able to see your application running with out any security problems.

Please feel free to ask all your questions related to this new feature or ask for more information if you need so.

I hope you have found this information useful. 

Happy MySQL/Net Codding!

Some useful references related:

Connection to MySql Server  (http://dev.mysql.com/doc/refman/5.1/en/connecting.html)

Windows Authentication (http://blogs.oracle.com/mysql_wna_plugin/entry/windows_native_authentication_for_mysql)

The following example shows how you can use the MySQLClientPermission class to restrict access to a specific server name and a database, while allowing any value for the User Id and Password within the connection string:

MySqlClientPermission permission = new MySqlClientPermission(PermissionState.None);

permission.Add("server=localhost;database=test;", " user id=; password=;",

KeyRestrictionBehavior.AllowOnly);

permission.PermitOnly();

MySqlConnection myconn = new MySqlConnection();

myconn.ConnectionString = "server=localhost; user id=QueryUser; database=test;";

myconn.Open();  // Attempt to use the connection string

The first line of code creates a new instance of the MySqlClientPermission class. Notice the value on the constructor method that restricts all connections strings.  Then you must add the connection strings that you want to allow by calling the Add method, as seen on the second line. The first argument should be the set of connections strings that you want to permit in a list with all the required keys and values.

For this case we're defining the server name and database name. All the connections must have these specified values in order to pass the security check. The second argument is a semi-colon delimited list of all the optional attributes. All the connection strings can have any value for these attributes to pass the security check. The third and final argument controls whether you're granting or denying permission for the connection strings that match this pattern. 

If the connection string that you use after this security definition does not match all the requirements, the attempt to do the connection will throw a SecurityException before even attempting to connect to the specified database.

The MySqlClientPermission instance can have multiple connections and any call to MySqlConnection.Open will not succeed if the connection string fails at least one of those checks.

It is always a good practice that you start by restricting all permissions and then allow the specific access your application requires.

Happy MySql/Net Codding!! 

 Intellisense Support in Visual Studio

One of the cool features coming in Connector/NET 6.5 is the support in Visual Studio 2010 of Intellisense for MySql files.

As you probably know, the capability of editing mysql files (in the way of both .mysql raw files included in the solution and stored procedures/functions from Server Explorer) has been around for a while, yet a missing piece of the puzzle was to have advanced completion of sql statements in those files… until now.

Let’s explore the set of features currently implemented as part of Intellisense support.

Note: For completion intellisense features to work a database connection must be properly configured, see images below

For Server Explorer items, the connection is the root of the elements.

For .mysql files, the connection is individually configured using the Connect to MySql toolbar button.

Also to trigger the completion features you just either use the standard Visual Studio shortcut “Control+J” or start typing the name of an object. Both ways to trigger intellisense work in all syntactical contexts.

a) Table Completion

Table completion means showing the list of tables for the current connection database in the proper syntactical context. Basically this means any part of a sql sentence where the parser expects a table. Some examples of this feature follow:

After the “from” clause in a select, you can press Control+J and get a list of all the tables from the current connection database.

After selecting one of the options, the text appears wrapped in quotes (to cover the case when the table name has whitespaces or is a mysql reserved word).

Or you can start typing the name of a table, and the list shows only those items that match.

Another example, after an inner join.

Another example, in an update statement. Also notice that you can have several sentences on the file, but the previous sentences must be correct syntactically (included being finished with a semicolon).

Another example, on the insert statement.

As expected, combinations like insert into select, also work.

Table completion for a delete statement.

For show create table statements.

For truncate statements.

And of course there are many others.

b) Column Completion

Column completion means showing the list of columns for the current connection database table or tables in the proper syntactical context. Basically this means any part of a sql sentence where the parser expects a column. Some examples of this feature follow:

After a select without from clause you can get, by Control+J, the list of columns for all tables in the current database.

If you type c, the lists shown filters out items whose name doesn’t start with the characters typed.

Things get more interesting when there is a context restricting the tables to use, like here, after the “*, “.

What if you add the same table several times with different alias? Then the list of columns is prefixed with the alias name, not the table name. Also works in where clauses.

“Set” clause in Update statements.

“Order by” clauses.

“On” clause in a left join select statement.

Column completion on insert into statements.

And other cases not showed here.

If you want to see Intellisense within a stored procedure definition, the rest of the stored procedure (excluding the sentence currently being edited) must be syntactically correct.

c) Stored procedure name Completion

Stored procedure name completion means showing the list of stored procedures in the proper syntactical context.

For the call statement, you get the list of stored procedures; notice that when you highlight one, its signature appears as a tooltip.

For those of you interested in compiler technology, behind the scenes these intellisense features are powered by an ANTLR generated parser, this parser will also be the foundation for other interesting features…

Anyway, let us know what you think, if there are other things you want to see on Intellisense support or in the Connector/NET in general. (Or you can open a bug / feature request at http://bugs.mysql.com, Connector/NET category).

I've been working on MySQL and .NET technologies for the past 8 years and I'm very proud to introduce a couple of people who have been and will continue be working on my team.  

Fernando Gonzalez currently serves as leader of our Connector/Net team and has just completed some early work on major intellisense improvements on Connector/Net 6.5.  He's done work on developing a new parser for our product.  We look forward to Fernando being a team leader and productive member of our team!

Gabriella Martinez has been working with Fernando on 6.5 and recently completed work on several new features including new milliseconds support and better support for partial trust scenarios. Gabriella will soon be moving to a new project that we look forward to announcing in the near future. Gabriella has already proven to be a very effective developer and important addition to the team.

We have 3 more developers starting on Jan 2 and I can't wait to write a followup to this post introducing those guys.  We are expanding our team and doing some great things with MySQL, Windows, and .NET.  2011 has been a very good year and we look forward to 2012 being even better!

Merry Christmas and Happy New Year! 

Version 6.4.4 is intended for use with versions of MySQL from 5.0 – 5.5

It is now available in source and binary form from here and mirror sites (note that not all mirror sites may be up to date at this point of time- if you can’t find this version on some mirror, please try again later or choose another download site.)

The release is also available for download on the My Oracle Support (MOS) and will be available from Oracle eDelivery.

This release includes several bug fixes including a fix to using Windows authentication.  Please review the change log and documentation for a review of what changed.

Enjoy and thanks for the support!

Version 6.4.3 is intended for use with versions of MySQL from 5.0 – 5.5

It is now available in source and binary form from [http://dev.mysql.com/downloads/connector/net/6.4.html] and mirror
sites (note that not all mirror sites may be up to date at this point of time
- if you can’t find this version on some mirror, please try again later or choose another download site.)
The release is also available for download on the My Oracle Support (MOS) and will be available from Oracle eDelivery.

** New features found in 6.4 include (please see release notes for more information) **

* Windows Authentication*
This release includes our new support for Windows authentication when connecting to MySQL Server 5.5.

* Table Caching *
We are also introducing a new feature called table caching.  This feature makes it possible to cache the rows of slow changing tables on the client side.

* Simple connection fail-over support *

We are also including some SQL generation improvements related to our entity framework provider.   Please review the change log that ships with the product for a complete list of changes and enhancements.

Enjoy and thanks for the support!

Version 6.2.5 is intended for use with versions of MySQL from 4.1 – 5.1.  It is not suitable for use with MySQL 5.5 or later.

It is now available in source and binary form from [http://dev.mysql.com/downloads/connector/net/] and mirror
sites (note that not all mirror sites may be up to date at this point of time
- if you can’t find this version on some mirror, please try again later or choose another download site.)

This update includes more than 45 fixes from 6.2.4.  Please review the change log that is included with the product to determine the exact nature of the changes.

Enjoy and thanks for the support!

Version 6.1.6 is intended for use with versions of MySQL from 4.1 – 5.1.  It is not suitable for use with MySQL 5.5 or later.

It is now available in source and binary form from here and mirror sites (note that not all mirror sites may be up to date at this point of time
- if you can’t find this version on some mirror, please try again later or choose another download site.)

This update includes more than 35 fixes from 6.1.5.  Please review the change log that is included with the product to determine the exact nature of the changes.

Enjoy and thanks for the support!

Version 6.4.2 is intended for use with versions of MySQL from 5.0 – 5.5

It is now available in source and binary form from here and mirror sites (note that not all mirror sites may be up to date at this point of time
- if you can’t find this version on some mirror, please try again later or choose another download site.) 

New features found in 6.4 include (please see release notes for more information)

• Windows Authentication — This release includes our new support for Windows authentication when connecting to MySQL Server 5.5. 
• Table Caching — We are also introducing a new feature called table caching.  This feature makes it possible to cache the rows of slow changing tables on the client side. 
• Simple connection fail-over support — We are also including some SQL generation improvements related to our entity framework provider.  

Please review the change log that ships with the product for a complete list of changes and enhancements.

Enjoy and thanks for the support!