Baytek Software Team

Tuesday, November 18, 2008

Code documentation with SandCastle

1- Install sandcastle (latest release)
2- Sandcastle is command line driven. No GUI. Install this GUI tool to make life easy.
3- You must enable XML documentation file check box for each project. This will create an xml file along with each assembly.
4- Take each assembly and xml file drag and drop it into the tool.
5- Third party LIBS and assemblies that you do not have xml doc for can be excluded using BUILD/Dependencies section.
6- Use VISIBILITY/ApiFilter to cut down on what gets compiled into the help file. Otherwise it becomes too overwhelming
7- Doc for XML tags
Doc1
Doc2
Doc3

Friday, October 31, 2008

Using group by the right way

Here are two great articles about the usage of Group By:

SQL GROUP BY techniques
More on GROUP BY; Examining SUM(Distinct)

Thanks to Jeff Smith.

In a nut-shell, instead of this:


SELECT
  C.CustomerID, C.CustomerName,  
  C.CustomerType, C.Address1, C.City,
  C.State, SUM(S.Sales) as TotalSales
FROM
  Customers C
INNER JOIN Sales S
  ON C.CustomerID = S.CustomerID
GROUP BY
  C.CustomerID, C.CustomerName,
  C.CustomerType, C.Address1, C.City, C.State

Use this:


SELECT
  C.CustomerID, C.CustomerName,
  C.CustomerType, C.Address1, C.City,
  C.State, S.TotalSales
FROM
  Customers C
INNER JOIN
  (SELECT 
     CustomerID, SUM(Sales) as TotalSales
   FROM
     Sales
   GROUP BY 
     CustomerID) S
ON
  C.CustomerID = S.CustomerID

This way you don’t need to include bunch of fields in your group by clause unnecessarily.

Wednesday, October 15, 2008

How to find out which process is locking a DLL

1- Start->Run and Open Cmd box
2- Type and execute the following
tasklist /m mydll.dll

and it will return a process list that have loaded your DLL!

Cool ha!

"tasklist /?" will give you a list of other things you can do with this utility.

Tuesday, September 30, 2008

Macro for Visual Studio 2005 Keyboard Shortcuts

Most people don't know this, but there are actually over 450 keyboard shortcuts in Visual Studio by default. But there is no easy way to find out all the keyboard shortcuts inside Visual Studio. You can find out what all the default keyboard shortcuts are by writing a simple macro to enumerate all of them. The following is the code for this.


Imports System
Imports EnvDTE
Imports EnvDTE80
Imports EnvDTE90
Imports System.Diagnostics
Imports System.IO

Public Module Module1

    Public Sub ListShortcutsInHTML()

        'Declare a StreamWriter
        Dim sw As System.IO.StreamWriter
        sw = New StreamWriter("c:\\demo\\Shortcuts.html")

        'Write the beginning HTML
        WriteHTMLStart(sw)

        ' Add a row for each keyboard shortcut
        For Each c As Command In DTE.Commands
            If c.Name <> "" Then
                Dim bindings As System.Array
                bindings = CType(c.Bindings, System.Array)
                For i As Integer = 0 To bindings.Length - 1
                    sw.WriteLine("<tr>")
                    sw.WriteLine("<td>" + c.Name + "</td>")
                    sw.WriteLine("<td>" + bindings(i) + "</td>")
                    sw.WriteLine("</tr>")
                Next

            End If
        Next

        'Write the end HTML
        WriteHTMLEnd(sw)

        'Flush and close the stream
        sw.Flush()
        sw.Close()
    End Sub
    Public Sub WriteHTMLStart(ByVal sw As System.IO.StreamWriter)
        sw.WriteLine("<html>")
        sw.WriteLine("<head>")
        sw.WriteLine("<title>")

        sw.WriteLine("Visual Studio Keyboard Shortcuts")
        sw.WriteLine("</title>")
        sw.WriteLine("</head>")

        sw.WriteLine("<body>")
        sw.WriteLine("<h1>Visual Studio 2005 Keyboard Shortcuts</h1>")
        sw.WriteLine("<font size=""2"" face=""Verdana"">")
        sw.WriteLine("<table border=""1"">")
        sw.WriteLine("<tr BGCOLOR=""#018FFF""><td align=""center""><b>Command</b></td><td align=""center""><b>Shortcut</b></td></tr>")


    End Sub

    Public Sub WriteHTMLEnd(ByVal sw As System.IO.StreamWriter)
        sw.WriteLine("</table>")
        sw.WriteLine("</font>")
        sw.WriteLine("</body>")
        sw.WriteLine("</html>")
    End Sub

End Module

To use this macro, go to Tools, select Macros, and then choose Macros IDE. . . to launch the Macros IDE. Expand the MyMacros project, MyMacros namespace and double-click on Module1. Simply copy Listing 1 to the Macros IDE and run the macro. After running the macro, you would have produced a keyboard shortcuts reference for Visual Studio. Open your output at C:\demo\Shortcuts.html.

Sunday, September 21, 2008

How to lock a table in SQL 2005

You would ask yourself why anyone would want to lock a table on purpose. Well… We just had an interesting bug related to table locking. A job in SQL was scheduled to run every night and it took over 10 minutes to complete. During this time it was locking a table exclusively. Of course, in response to this, our middle tier was blowing chunks as it tried to insert records into the locked table. Our insert would result in SQL time out and create an unpredictable behavior then on.
I needed to simulate the table lock situation so I could make the code more resilient. At a minimum I wanted to be able to trap the time out and log it. Also, we wanted to rollback everything up to that point as well.

Here are the steps to Lock and Unlock a table

1- Open a window in Microsoft SQL server Management Studio and open a new SQL window:
2- Use the following code as a template to setup your Lock/Unlock mechanism.


Begin transaction
update top (1) Product WITH (TABLOCK)  set Name=’Cheetos’ where ProductID=100
RollBack

3- TO LOCK the table highlight the first two lines (Begin trans + update) and execute them by hitting CTRL+E. At this point table is locked.
4- TO UNLOCK the table highlight the last line (Rollback) and execute it by hitting CTRL+E.

Use the 3 and 4 to repeatedly to lock and unlock the table. Since each time you are rolling back, there will be no change to the content of the table.

After 3 the table Products will be locked. You will not be able to select, insert, update or delete from the table products as long as this transaction is not concluded with a commit or rollback. You may want open a new window in Microsoft SQL server Management Studio and try the following:


select top 1 * from Products

The statement above will hangup and wait for the completion of the transaction we started in step 2.
Similarly, you can run your code and see the same timeout behavior.

Saturday, September 20, 2008

SQL 2005 Table Lock Hint Syntax Change

Syntax for locking tables has been changed in SQL 2005 which makes placing the ‘WITH’ keyword in parentheses illegal.

The following was acceptable in SQL 2000; however, no longer is the case with 2005.
The following is true for SQL 2005:

WRONG

UPDATE Products (WITH NOLOCK) 
 SET Name = 'Cheetos'    
WHERE ProductCat = 'JunkFood'

CORRECT

UPDATE Products WITH (NOLOCK) 
SET Name = 'Cheetos'    
WHERE ProductCat = 'JunkFood'

Thursday, September 18, 2008

Realtime Applications with Flex & Actionscript

Hi everybody. We are developing an SDK for developers out there to easily program realtime applications. (Chat, Multiplayer Games etc)

You can find more info here.