CJ Wang's Blog

SQL Server Data Type Mappings (ADO.NET, .NET Framework 3.5)

cjwang — Wed, 02 Dec 2009 21:30:38 +0000

Original source: MSDN http://msdn.microsoft.com/en-us/library/cc716729.aspx#

SQL Server and the .NET Framework are based on different type systems. For example, the .NET Framework Decimal structure has a maximum scale of 28, whereas the SQL Server decimal and numeric data types have a maximum scale of 38. To maintain data integrity when reading and writing data, the SqlDataReader exposes SQL Server–specific typed accessor methods that return objects of System.Data.SqlTypes as well as accessor methods that return .NET Framework types. Both SQL Server types and .NET Framework types are also represented by enumerations in the DbType and SqlDbType classes, which you can use when specifying SqlParameter data types.

The following table shows the inferred .NET Framework type, the DbType and SqlDbType enumerations, and the accessor methods for the SqlDataReader.

SQL Server Database Engine type	.NET Framework type	SqlDbType enumeration	SqlDataReader SqlTypes typed accessor	DbType enumeration	SqlDataReader DbType typed accessor
bigint	Int64	BigInt	GetSqlInt64	Int64	GetInt64
binary	Byte[]	VarBinary	GetSqlBinary	Binary	GetBytes
bit	Boolean	Bit	GetSqlBoolean	Boolean	GetBoolean
char	String Char[]	Char	GetSqlString	AnsiStringFixedLength, String	GetString GetChars
date (SQL Server 2008 only)	DateTime	Date	GetSqlDateTime	Date	GetDateTime
datetime	DateTime	DateTime	GetSqlDateTime	DateTime	GetDateTime
datetime2 (SQL Server 2008 only)	DateTime2	DateTime2	GetSqlDateTime	DateTime2	GetDateTime
datetimeoffset (SQL Server 2008 only)	DateTimeOffset	DateTimeOffset	none	DateTimeOffset	GetDateTimeOffset
decimal	Decimal	Decimal	GetSqlDecimal	Decimal	GetDecimal
FILESTREAM attribute (varbinary(max)	Byte[]	VarBinary	GetSqlBytes	Binary	GetBytes
float	Double	Float	GetSqlDouble	Double	GetDouble
image	Byte[]	Binary	GetSqlBinary	Binary	GetBytes
int	Int32	Int	GetSqlInt32	Int32	GetInt32
money	Decimal	Money	GetSqlMoney	Decimal	GetDecimal
nchar	String Char[]	NChar	GetSqlString	StringFixedLength	GetString GetChars
ntext	String Char[]	NText	GetSqlString	String	GetString GetChars
numeric	Decimal	Decimal	GetSqlDecimal	Decimal	GetDecimal
nvarchar	String Char[]	NVarChar	GetSqlString	String	GetString GetChars
real	Single	Real	GetSqlSingle	Single	GetFloat
rowversion	Byte[]	Timestamp	GetSqlBinary	Binary	GetBytes
smalldatetime	DateTime	DateTime	GetSqlDateTime	DateTime	GetDateTime
smallint	Int16	SmallInt	GetSqlInt16	Int16	GetInt16
smallmoney	Decimal	SmallMoney	GetSqlDecimal	Decimal	GetDecimal
sql_variant	Object *	Variant	GetSqlValue *	Object	GetValue *
text	String Char[]	Text	GetSqlString	String	GetString GetChars
time (SQL Server 2008 only)	TimeSpan	Time	none	Time	GetDateTime
timestamp	Byte[]	Timestamp	GetSqlBinary	Binary	GetBytes
tinyint	Byte	TinyInt	GetSqlByte	Byte	GetByte
uniqueidentifier	Guid	UniqueIdentifier	GetSqlGuid	Guid	GetGuid
varbinary	Byte[]	VarBinary	GetSqlBinary	Binary	GetBytes
varchar	String Char[]	VarChar	GetSqlString	AnsiString, String	GetString GetChars
xml	Xml	Xml	GetSqlXml	Xml	none

* Use a specific typed accessor if you know the underlying type of the sql_variant.

Why there is a Windows “N” version

cjwang — Sun, 25 Oct 2009 21:49:53 +0000

Windows XP and Windows 7 all have a “N” version. The difference from the non-N version is the N does not bundle Media Player. Here explains all: http://crave.cnet.co.uk/software/0,39029471,49303415,00.htm

MS SQL Server BIT data type, 1 = True and 0 = False

cjwang — Sun, 25 Oct 2009 21:45:18 +0000

From MSDN http://msdn.microsoft.com/en-us/library/ms177603.aspx

“The string values TRUE and FALSE can be converted to bit values: TRUE is converted to 1 and FALSE is converted to 0.”

Extend Virtual PC VHD file size

cjwang — Sun, 25 Oct 2009 04:38:59 +0000

Utilities you need:
VHD Resizer (free, http://vmtoolkit.com/)
DISKPART.EXE (free, Microsoft)

1. Run VHD Resizer. Save the new VHD in a new file.
2. Attach the new VHD on the VPC. Boot up the VPC from the old VHD with the new VHD attached.
3. After #2, In the VPC, go to the DOS command prompt, enter ‘diskpart’. Select the right disk and volume on the new VHD and use the command ‘Extend’.

Useful Links:
http://vmtoolkit.com/files/folders/converters/entry8.aspx
http://support.microsoft.com/kb/325590
http://support.microsoft.com/kb/300415
http://www.enusbaum.com/blog/2008/02/07/expand-a-virtual-pc-vhd-file-and-extend-the-partition/
http://blogs.msdn.com/benjguin/archive/2007/10/04/how-to-expand-a-vhd-disk.aspx

Screen capture of the diskpart command when I extended the partition on the new VHD.

C:\>diskpart

Microsoft DiskPart version 5.1.3565

DISKPART> LIST DISK

Disk ### Status      Size     Free     Dyn Gpt
——– ———- ——- ——- — —
Disk 0    Online        30 GB      0 B
Disk 1    Online        60 GB    30 GB

DISKPART> SELECT DISK 1

Disk 1 is now the selected disk.

DISKPART> LIST VOLUME

Volume ### Ltr Label        Fs     Type        Size     Status     Info
———- — ———– —– ———- ——- ——— ——–
Volume 0     D   VMADDITIONS CDFS   DVD-ROM       28 MB
Volume 1     C                NTFS   Partition     30 GB Healthy    System
Volume 2     E                NTFS   Partition     30 GB Healthy

DISKPART> SELECT VOLUME 2

Volume 2 is the selected volume.

DISKPART> EXTEND

DiskPart successfully extended the volume.

DISKPART> EXIT

Leaving DiskPart…

C:\>

Convert Paint.NET file to PSD (PhotoShop Document)

cjwang — Tue, 28 Apr 2009 07:19:40 +0000

Paint.NET is an open source program that can do some photo editing. Just run into the situation that I need to convert my art works done in Paint.NET to PSD file (PhotoShop Document file format).

Here is how:
1. download the PSD for Paint.NET plug-in from here.
2. Install the plug-in by copying the dll file to “C:\Program Files\Paint.NET\FileTypes”.

Voila!

BirdPick Tea House

cjwang — Thu, 23 Apr 2009 18:05:42 +0000

A pleasent surprise when walking out of the parking log at old town Pasadena.

Free E-Books offer to celebrate the 25th anniversary of Microsoft Press

cjwang — Mon, 20 Apr 2009 15:32:17 +0000

Saw this from the VB Team’s blog. Microsoft offers two free E-Books to celebrate the 25th anniversary of Microsoft Press! This offer ends April 22.

* Windows Small Business Server 2008 Administrator’s Companion by Charlie Russel and Sharon Crawford (27 chapters, 3 appendices, 712 pages)

* Microsoft Visual Basic 2008 Express Edition: Build a Program Now! by Patrice Pelland (9 chapters, Glossary, 254 pages)

Click on this link to get the book! (http://blogs.msdn.com/vbteam/archive/2009/04/16/two-free-e-books-available-till-april-22th-to-celebrate-ms-press-s-25th-b-day-daniel-walzenbach.aspx)

Note: You need to register first. After registration, you will receive an e-mail from Microsoft to verify your e-mail address. Open that e-mail, click on the link to verify. You will be forwarded to the download page.

Building VM for the developer team

cjwang — Mon, 20 Apr 2009 06:43:49 +0000

I have been using virtual machines to simplified the developers’ development environment since 2005. There are some pro’s and con’s, but overall, IMO, it’s worth it. It saves lots of time because the developers don’t need to rebuild machines any more. And the development environment can be easily standardized.

David Douglass wrote a blog on creating a VM for a developer machine (http://geekswithblogs.net/.NETonMyMind/archive/2007/04/29/112086.aspx). It includes:

1) List of developer’s utilities to install

2) Configure some settings such as folder property to display known file extensions

3) Seal the image using SysPrep
http://technet.microsoft.com/en-us/library/bb457080.aspx
Good reference here: http://www.windowsnetworking.com/articles_tutorials/Creating-Sysprep-Image-Library-Virtual-PC.html

Silverlight 2 Study Note – 1

cjwang — Wed, 12 Nov 2008 00:25:18 +0000

Getting started from here to download all the tools you need.
http://silverlight.net/GetStarted/

There is a patterns & practices Composite Application Guidance for WPF and Silverlight.
Read it here: http://www.codeplex.com/CompositeWPF

Some Silverlight controls:
TreeView control: http://www.codeplex.com/SilverlightTreeView
Google & Virtual Earth Map control, etc… : http://www.codeplex.com/SLExtensions

Microsoft Health Common User Interface (CUI) announced to change the technology. The existing controls were built in ASP.NET AJAX and .NET WinForms. For future releases, all new controls will be developed in Windows Presentation Foundation (WPF) and Silverlight. It’s a pleasant surprise.

This is a framework. I didn’t try it so I don’t know how it works.
Visual Web GUI framework: http://www.codeplex.com/VWGSilverlight

Michael Washington has built a Silverlight framework called SilverlightDesktop.

DevConnections 2008 – Monday, Nov. 10, 2008

cjwang — Tue, 11 Nov 2008 18:15:25 +0000

This week, I am at DevConnection conference. I am going to post my note of the conference here.

Monday is the pre-conference. I attended the Silverlight 2.0 class, and found it is promising (finally).

Silverlight 1.x to me is not practical at all since I am building business applications. It is pretty much equivalent to Flash 2.0, which Macromedia (now acquired by Adobe) released about a decade ago! Now I saw the good opportunity and tool to build RIA, Rich Internet Applications.

Here are the notes:

Get started on Sliverlight 2 here. Download all the stuff you need and start having fun.
http://silverlight.net/GetStarted/

You don’t want to miss this. Must see.
ScottGu’s end-to-end tutorial
http://weblogs.asp.net/scottgu/pages/silverlight-2-end-to-end-tutorial-building-a-digg-search-client.aspx

Wanna be on top of Silverlight news? Check out these two web site frequently:
http://twitter.com/silverlightnews
http://silverlightcream.com/

Download sample codes for today’s Silverlight 2 class here:
http://weblogs.asp.net/dwahlin/archive/2008/11/10/silverlight-2-development-workshop-code.aspx

More Silverlight controls:
This one has the ‘WrapPanel” control. Also, RangeSlider.

http://www.codeplex.com/SharpControls

How to set the format for the textblock in Silverlight 2
http://blogs.microsoft.co.il/blogs/tamir/archive/2008/06/19/quick-silverlight-tip-how-to-set-format-and-validate-value-in-textbox.aspx

A few more Silverlight resources here:
http://blogs.msdn.com/silverlight_sdk/default.aspx

Excellent reflector tool: http://www.red-gate.com/products/reflector/

As you know, Silverlight 2 now only works with GET and POST. It cannot update, nor delete via REST.
There is a very good post on how to “tunnel” PUT and DELETE via REST through Silverlight 2.
http://blogs.msdn.com/bags/