Sunday, 22 November 2009

Using the HandleError attribute

You can conveniently handle exceptions in ASP.Net MVC using the [HandleError] attribute. However, there are a few things to bear in mind.

Update Web.config

You must add a customerrors section to Web.config. If you don’t do this nothing will happen.

<configuration>
    <system.web>
        <customErrors mode="On" />
    </system.web>
<configuration>

Beware of adding the attribute to the controller at class level

If you add the attribute to your controller class at the class level it can override any settings made on controller actions.

using System;
using System.Web.Mvc;
using Mail.Merge.Core.Domain;
using Mail.Merge.Core.Repository;
using Mail.Merge.Core.Repository.Specification;
using Mail.Merge.UI.MVC.Extensions;

namespace Mail.Merge.UI.MVC.Controllers
{
    [HandleError] // This will override any settings made on controller actions
    public class SalutationController : Controller
    {
        IRepository _repository;

        public SalutationController(IRepository repository)
        {
            _repository = repository;
        }

        // code snipped ...

        [AcceptVerbs(HttpVerbs.Post)]
        [HandleError(ExceptionType=typeof(SqlException),View="DeletionError")]
        public ActionResult Delete(int id, string button)
        {
            // code snipped ...
            return RedirectToAction("Index");
        }
    }
}

You can fix this behaviour though by modifying the [HandleError] attributes to use explicit ordering. For example in the code above set the attribute at the class level to be [HandleError(Order=0)]. Because the default order number is –1 this will force the controller action error handling filter to take precedence. 

InvalidDataAccessApiUsageException with Spring and NHibernate

If you get a Spring.Dao.InvalidDataAccessApiUsageException with the following message…

“Write operations are not allowed in read-only mode (FlushMode.NEVER) - turn your Session into FlushMode.AUTO or remove 'readOnly' marker from transaction definition”

…check that you have added the [Transaction(ReadOnly = false)] attribute to the appropriate data access method (assuming it’s a method that modifies data). Alternatively, if the attribute is already present, check that ReadOnly is not set to true.

Saturday, 21 November 2009

NullReferenceException if not using default binding

If you are not using the default binding mechanism in MVC and you are doing you own data validation (i.e. adding your own errors to the ModelState) the HtmlHelper class can throw a NullReferenceException. This occurs when there are validation errors.

System.NullReferenceException was unhandled by user code
  Message="Object reference not set to an instance of an object."
  Source="System.Web.Mvc"
  StackTrace:
       at System.Web.Mvc.HtmlHelper.GetModelStateValue(String key, Type destinationType)
       at System.Web.Mvc.Html.InputExtensions.InputHelper(HtmlHelper htmlHelper, InputType inputType, String name, Object value, Boolean useViewData, Boolean isChecked, Boolean setId, Boolean isExplicitValue, IDictionary`2 htmlAttributes)
       at System.Web.Mvc.Html.InputExtensions.TextBox(HtmlHelper htmlHelper, String name, Object value, IDictionary`2 htmlAttributes)
       at System.Web.Mvc.Html.InputExtensions.TextBox(HtmlHelper htmlHelper, String name, Object value)
       at ASP.views_salutation_edit_aspx.__RenderContent2(HtmlTextWriter __w, Control parameterContainer) in c:\source\MUI.MVC\Views\Salutation\Edit.aspx:line 25
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Control.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at ASP.views_shared_site_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in c:\source\UI.MVC\Views\Shared\Site.Master:line 29
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Control.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children)
       at System.Web.UI.Control.RenderChildren(HtmlTextWriter writer)
       at System.Web.UI.Page.Render(HtmlTextWriter writer)
       at System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer)
       at System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter)
       at System.Web.UI.Control.RenderControl(HtmlTextWriter writer)
       at System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint)

The MVC Framework will try to find an AttemptedValue for every error it finds so you must add them or MVC will throw an exception.

AttemptedValues are automatically populated when you use default binding, if you call UpdateModel() or by passing the object to bind as a parameter. For example:

public ActionResult Create(MyClass myObject);

If you want to do it yourself you need to call ModelState.SetModelValue. For example:

ModelState.SetModelValue("Name", new ValueProviderResult(ValueProvider["Name"].AttemptedValue, salutation.Name, System.Globalization.CultureInfo.CurrentCulture));

Wednesday, 18 November 2009

Measuring query performance

To measure query performance you can use the SQL Profiler to log to a table then run the following queries.

Most frequent queries

SELECT
    DISTINCT
        CAST(textdata AS varchar(5000)) AS textdata,
        COUNT(duration) AS Occurences,
        AVG(duration) AS AvgDuration,
        SUM(duration) AS TotalDuration
FROM    [trace table name here]
WHERE   LoginName = 'login name here'
        AND textdata NOT LIKE '--%'
        AND CAST(textdata AS VARCHAR(5000)) <> 'exec sp_reset_connection'
GROUP BY CAST(textdata AS VARCHAR(5000))
ORDER BY COUNT(duration) DESC

Most inefficient queries

SELECT DISTINCT
        CAST(textdata AS VARCHAR(5000)) AS textdata,
        COUNT(duration) AS Occurences,
        AVG(duration) AS AvgDuration,
        SUM(duration) AS TotalDuration
FROM    [trace table name here]
WHERE   LoginName = 'login name here'
        AND textdata NOT LIKE '--%'
        AND CAST(textdata AS VARCHAR(5000)) <> 'exec sp_reset_connection'
GROUP BY CAST(textdata AS VARCHAR(5000))
ORDER BY AVG(duration) DESC

Monday, 16 November 2009

Commands in WPF

The GoF Command design pattern is defined as  "encapsulate a request as an object, thereby letting you parameterize clients with different requests, queue or log requests, and support undoable operations". WPF Commands provide methods for decoupling UI events, the handling of these events and the registration of UI elements interested in handling the events.

WPF Commands are really very much like events but they offer some advantages:

  • Reuse – Commands can be registered with multiple controls allowing for reuse.
  • Routing – Commands based on the RoutedCommand base class can participate in event bubbling.
  • XAML integration – Commands can be defined and registered with controls in XAML.
  • Input gestures – There are a stack of build-in commands which are already configured to handle input gestures (e.g. using ApplicationCommands.Paste, a RoutedUICommand, will give you all Ctrl-V etc. out of the box).
  • Testability – Commands can be tested.
  • Localisation – Commands can be localised (which is done for you with built-in commands).

All WPF commands must implement a simple interface, ICommand:

public interface ICommand
{
    // Methods.
    void Execute(object parameter);
    bool CanExecute(object parameter);

    // Events.
    event EventHandler CanExecuteChanged;
}
  • Execute - contains the logic to perform the action that makes up the command
  • CanExecute - returns a value that determines if the command is currently valid
  • CanExecuteChanged event - raised when the value returned by the CanExecute method has changed

Built-in commands take advantage of CanExecute and CanExecuteChanged to enable/disable functionality for you (i.e. registered controls’ will automatically become enabled/disabled appropriately).

See http://www.microsoft.com/belux/msdn/nl/community/columns/jdruyts/wpf_commandpattern.mspx

See http://msdn.microsoft.com/en-us/library/ms752308.aspx

More to follow on this one…

Sunday, 15 November 2009

Dashboard output in CruiseControl.Net 1.5

This applies to CruiseControl.Net 1.5x which doesn’t show much in the way of output reports by default.
There are basically 2 types of output:
  1. Build report
  2. XSL report
These types of output are enabled by CruiseControl.Net plugins. The build report output appears in the build summary when you first view the build results in the dashboard. The XSL reports appear as menu items on the left when you are viewing build results.
Both types of report are enabled by XSL files that are located in the <web dashboard installation>\xsl folder. 
To modify the types of output you need to edit the dashboard.config file located in the web dashboard installation folder.
<?xml version="1.0" encoding="utf-8"?>
<dashboard>
  <remoteServices>
  ...
  </remoteServices>
  <plugins>
    <farmPlugins>
    ...
    </farmPlugins>
    <serverPlugins>
      ...
    </serverPlugins>
    <projectPlugins>
      <projectReportProjectPlugin />
      <viewProjectStatusPlugin />
      <latestBuildReportProjectPlugin />
      <viewAllBuildsProjectPlugin />
    </projectPlugins>
    <buildPlugins>
      <buildReportBuildPlugin>
        <xslFileNames>
          <xslFile>xsl\header.xsl</xslFile>
          <xslFile>xsl\modifications.xsl</xslFile>
          <xslFile>xsl\unittests.xsl</xslFile>
        </xslFileNames>
      </buildReportBuildPlugin>
      <buildLogBuildPlugin />
      <xslReportBuildPlugin xslFileName="xsl\AlternativeNUnitDetails.xsl" actionName="NUnitBuildReport" description="NUnit Report"></xslReportBuildPlugin>
      <xslReportBuildPlugin xslFileName="xsl\timing.xsl" actionName="NUnitTimingReport" description="NUnit Timing"></xslReportBuildPlugin>
      <xslReportBuildPlugin xslFileName="xsl\unittests.xsl" actionName="UnitTestsReport" description="Unit Tests"></xslReportBuildPlugin>
    </buildPlugins>
    <securityPlugins>
      <simpleSecurity />
    </securityPlugins>
  </plugins>
</dashboard>
The <buildreportbuildplugin> element contains a list of XSL files. The output generated by these files will appear in the build report.
The  <xslreportbuildplugin> elements contain one XSL file each. The output generated by these files will appear as individual XSL reports accessible via left-hand menu items in the build report.
Note: You will need to touch the dashboard web.config file to get the dashboard to read the modified dashboard.config file.

Tuesday, 10 November 2009

Generating insert statements

To generate insert statements from existing data create and run the following stored procedure (taken from http://vyaskn.tripod.com/code.htm).

SET NOCOUNT ON
GO

PRINT 'Using Master database'
USE master
GO

PRINT 'Checking for the existence of this procedure'
IF (SELECT OBJECT_ID('sp_generate_inserts','P')) IS NOT NULL --means, the procedure already exists
 BEGIN
  PRINT 'Procedure already exists. So, dropping it'
  DROP PROC sp_generate_inserts
 END
GO

--Turn system object marking on
EXEC master.dbo.sp_MS_upd_sysobj_category 1
GO

CREATE PROC sp_generate_inserts
(
 @table_name varchar(776),    -- The table/view for which the INSERT statements will be generated using the existing data
 @target_table varchar(776) = NULL,  -- Use this parameter to specify a different table name into which the data will be inserted
 @include_column_list bit = 1,  -- Use this parameter to include/ommit column list in the generated INSERT statement
 @from varchar(800) = NULL,   -- Use this parameter to filter the rows based on a filter condition (using WHERE)
 @include_timestamp bit = 0,   -- Specify 1 for this parameter, if you want to include the TIMESTAMP/ROWVERSION column's data in the INSERT statement
 @debug_mode bit = 0,   -- If @debug_mode is set to 1, the SQL statements constructed by this procedure will be printed for later examination
 @owner varchar(64) = NULL,  -- Use this parameter if you are not the owner of the table
 @ommit_images bit = 0,   -- Use this parameter to generate INSERT statements by omitting the 'image' columns
 @ommit_identity bit = 0,  -- Use this parameter to ommit the identity columns
 @top int = NULL,   -- Use this parameter to generate INSERT statements only for the TOP n rows
 @cols_to_include varchar(8000) = NULL, -- List of columns to be included in the INSERT statement
 @cols_to_exclude varchar(8000) = NULL, -- List of columns to be excluded from the INSERT statement
 @disable_constraints bit = 0,  -- When 1, disables foreign key constraints and enables them after the INSERT statements
 @ommit_computed_cols bit = 0  -- When 1, computed columns will not be included in the INSERT statement
 
)
AS
BEGIN

/***********************************************************************************************************
Procedure: sp_generate_inserts  (Build 22) 
  (Copyright © 2002 Narayana Vyas Kondreddi. All rights reserved.)
                                          
Purpose: To generate INSERT statements from existing data. 
  These INSERTS can be executed to regenerate the data at some other location.
  This procedure is also useful to create a database setup, where in you can 
  script your data along with your table definitions.

Written by: Narayana Vyas Kondreddi
         http://vyaskn.tripod.com

Acknowledgements:
  Divya Kalra -- For beta testing
  Mark Charsley -- For reporting a problem with scripting uniqueidentifier columns with NULL values
  Artur Zeygman -- For helping me simplify a bit of code for handling non-dbo owned tables
  Joris Laperre   -- For reporting a regression bug in handling text/ntext columns

Tested on:  SQL Server 7.0 and SQL Server 2000

Date created: January 17th 2001 21:52 GMT

Date modified: May 1st 2002 19:50 GMT

Email:   vyaskn@hotmail.com

NOTE:  This procedure may not work with tables with too many columns.
  Results can be unpredictable with huge text columns or SQL Server 2000's sql_variant data types
  Whenever possible, Use @include_column_list parameter to ommit column list in the INSERT statement, for better results
  IMPORTANT: This procedure is not tested with internation data (Extended characters or Unicode). If needed
  you might want to convert the datatypes of character variables in this procedure to their respective unicode counterparts
  like nchar and nvarchar
  

Example 1: To generate INSERT statements for table 'titles':
  
  EXEC sp_generate_inserts 'titles'

Example 2:  To ommit the column list in the INSERT statement: (Column list is included by default)
  IMPORTANT: If you have too many columns, you are advised to ommit column list, as shown below,
  to avoid erroneous results
  
  EXEC sp_generate_inserts 'titles', @include_column_list = 0

Example 3: To generate INSERT statements for 'titlesCopy' table from 'titles' table:

  EXEC sp_generate_inserts 'titles', 'titlesCopy'

Example 4: To generate INSERT statements for 'titles' table for only those titles 
  which contain the word 'Computer' in them:
  NOTE: Do not complicate the FROM or WHERE clause here. It's assumed that you are good with T-SQL if you are using this parameter

  EXEC sp_generate_inserts 'titles', @from = "from titles where title like '%Computer%'"

Example 5:  To specify that you want to include TIMESTAMP column's data as well in the INSERT statement:
  (By default TIMESTAMP column's data is not scripted)

  EXEC sp_generate_inserts 'titles', @include_timestamp = 1

Example 6: To print the debug information:
  
  EXEC sp_generate_inserts 'titles', @debug_mode = 1

Example 7:  If you are not the owner of the table, use @owner parameter to specify the owner name
  To use this option, you must have SELECT permissions on that table

  EXEC sp_generate_inserts Nickstable, @owner = 'Nick'

Example 8:  To generate INSERT statements for the rest of the columns excluding images
  When using this otion, DO NOT set @include_column_list parameter to 0.

  EXEC sp_generate_inserts imgtable, @ommit_images = 1

Example 9:  To generate INSERT statements excluding (ommiting) IDENTITY columns:
  (By default IDENTITY columns are included in the INSERT statement)

  EXEC sp_generate_inserts mytable, @ommit_identity = 1

Example 10:  To generate INSERT statements for the TOP 10 rows in the table:
  
  EXEC sp_generate_inserts mytable, @top = 10

Example 11:  To generate INSERT statements with only those columns you want:
  
  EXEC sp_generate_inserts titles, @cols_to_include = "'title','title_id','au_id'"

Example 12:  To generate INSERT statements by omitting certain columns:
  
  EXEC sp_generate_inserts titles, @cols_to_exclude = "'title','title_id','au_id'"

Example 13: To avoid checking the foreign key constraints while loading data with INSERT statements:
  
  EXEC sp_generate_inserts titles, @disable_constraints = 1

Example 14:  To exclude computed columns from the INSERT statement:
  EXEC sp_generate_inserts MyTable, @ommit_computed_cols = 1
***********************************************************************************************************/

SET NOCOUNT ON

--Making sure user only uses either @cols_to_include or @cols_to_exclude
IF ((@cols_to_include IS NOT NULL) AND (@cols_to_exclude IS NOT NULL))
 BEGIN
  RAISERROR('Use either @cols_to_include or @cols_to_exclude. Do not use both the parameters at once',16,1)
  RETURN -1 --Failure. Reason: Both @cols_to_include and @cols_to_exclude parameters are specified
 END

--Making sure the @cols_to_include and @cols_to_exclude parameters are receiving values in proper format
IF ((@cols_to_include IS NOT NULL) AND (PATINDEX('''%''',@cols_to_include) = 0))
 BEGIN
  RAISERROR('Invalid use of @cols_to_include property',16,1)
  PRINT 'Specify column names surrounded by single quotes and separated by commas'
  PRINT 'Eg: EXEC sp_generate_inserts titles, @cols_to_include = "''title_id'',''title''"'
  RETURN -1 --Failure. Reason: Invalid use of @cols_to_include property
 END

IF ((@cols_to_exclude IS NOT NULL) AND (PATINDEX('''%''',@cols_to_exclude) = 0))
 BEGIN
  RAISERROR('Invalid use of @cols_to_exclude property',16,1)
  PRINT 'Specify column names surrounded by single quotes and separated by commas'
  PRINT 'Eg: EXEC sp_generate_inserts titles, @cols_to_exclude = "''title_id'',''title''"'
  RETURN -1 --Failure. Reason: Invalid use of @cols_to_exclude property
 END


--Checking to see if the database name is specified along wih the table name
--Your database context should be local to the table for which you want to generate INSERT statements
--specifying the database name is not allowed
IF (PARSENAME(@table_name,3)) IS NOT NULL
 BEGIN
  RAISERROR('Do not specify the database name. Be in the required database and just specify the table name.',16,1)
  RETURN -1 --Failure. Reason: Database name is specified along with the table name, which is not allowed
 END

--Checking for the existence of 'user table' or 'view'
--This procedure is not written to work on system tables
--To script the data in system tables, just create a view on the system tables and script the view instead

IF @owner IS NULL
 BEGIN
  IF ((OBJECT_ID(@table_name,'U') IS NULL) AND (OBJECT_ID(@table_name,'V') IS NULL)) 
   BEGIN
    RAISERROR('User table or view not found.',16,1)
    PRINT 'You may see this error, if you are not the owner of this table or view. In that case use @owner parameter to specify the owner name.'
    PRINT 'Make sure you have SELECT permission on that table or view.'
    RETURN -1 --Failure. Reason: There is no user table or view with this name
   END
 END
ELSE
 BEGIN
  IF NOT EXISTS (SELECT 1 FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_NAME = @table_name AND (TABLE_TYPE = 'BASE TABLE' OR TABLE_TYPE = 'VIEW') AND TABLE_SCHEMA = @owner)
   BEGIN
    RAISERROR('User table or view not found.',16,1)
    PRINT 'You may see this error, if you are not the owner of this table. In that case use @owner parameter to specify the owner name.'
    PRINT 'Make sure you have SELECT permission on that table or view.'
    RETURN -1 --Failure. Reason: There is no user table or view with this name  
   END
 END

--Variable declarations
DECLARE  @Column_ID int,   
  @Column_List varchar(8000), 
  @Column_Name varchar(128), 
  @Start_Insert varchar(786), 
  @Data_Type varchar(128), 
  @Actual_Values varchar(8000), --This is the string that will be finally executed to generate INSERT statements
  @IDN varchar(128)  --Will contain the IDENTITY column's name in the table

--Variable Initialization
SET @IDN = ''
SET @Column_ID = 0
SET @Column_Name = ''
SET @Column_List = ''
SET @Actual_Values = ''

IF @owner IS NULL 
 BEGIN
  SET @Start_Insert = 'INSERT INTO ' + '[' + RTRIM(COALESCE(@target_table,@table_name)) + ']' 
 END
ELSE
 BEGIN
  SET @Start_Insert = 'INSERT ' + '[' + LTRIM(RTRIM(@owner)) + '].' + '[' + RTRIM(COALESCE(@target_table,@table_name)) + ']'   
 END


--To get the first column's ID

SELECT @Column_ID = MIN(ORDINAL_POSITION)  
FROM INFORMATION_SCHEMA.COLUMNS (NOLOCK) 
WHERE  TABLE_NAME = @table_name AND
(@owner IS NULL OR TABLE_SCHEMA = @owner)



--Loop through all the columns of the table, to get the column names and their data types
WHILE @Column_ID IS NOT NULL
 BEGIN
  SELECT  @Column_Name = QUOTENAME(COLUMN_NAME), 
  @Data_Type = DATA_TYPE 
  FROM  INFORMATION_SCHEMA.COLUMNS (NOLOCK) 
  WHERE  ORDINAL_POSITION = @Column_ID AND 
  TABLE_NAME = @table_name AND
  (@owner IS NULL OR TABLE_SCHEMA = @owner)



  IF @cols_to_include IS NOT NULL --Selecting only user specified columns
  BEGIN
   IF CHARINDEX( '''' + SUBSTRING(@Column_Name,2,LEN(@Column_Name)-2) + '''',@cols_to_include) = 0 
   BEGIN
    GOTO SKIP_LOOP
   END
  END

  IF @cols_to_exclude IS NOT NULL --Selecting only user specified columns
  BEGIN
   IF CHARINDEX( '''' + SUBSTRING(@Column_Name,2,LEN(@Column_Name)-2) + '''',@cols_to_exclude) <> 0 
   BEGIN
    GOTO SKIP_LOOP
   END
  END

  --Making sure to output SET IDENTITY_INSERT ON/OFF in case the table has an IDENTITY column
  IF (SELECT COLUMNPROPERTY( OBJECT_ID(QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + @table_name),SUBSTRING(@Column_Name,2,LEN(@Column_Name) - 2),'IsIdentity')) = 1 
  BEGIN
   IF @ommit_identity = 0 --Determing whether to include or exclude the IDENTITY column
    SET @IDN = @Column_Name
   ELSE
    GOTO SKIP_LOOP   
  END
  
  --Making sure whether to output computed columns or not
  IF @ommit_computed_cols = 1
  BEGIN
   IF (SELECT COLUMNPROPERTY( OBJECT_ID(QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + @table_name),SUBSTRING(@Column_Name,2,LEN(@Column_Name) - 2),'IsComputed')) = 1 
   BEGIN
    GOTO SKIP_LOOP     
   END
  END
  
  --Tables with columns of IMAGE data type are not supported for obvious reasons
  IF(@Data_Type in ('image'))
   BEGIN
    IF (@ommit_images = 0)
     BEGIN
      RAISERROR('Tables with image columns are not supported.',16,1)
      PRINT 'Use @ommit_images = 1 parameter to generate INSERTs for the rest of the columns.'
      PRINT 'DO NOT ommit Column List in the INSERT statements. If you ommit column list using @include_column_list=0, the generated INSERTs will fail.'
      RETURN -1 --Failure. Reason: There is a column with image data type
     END
    ELSE
     BEGIN
     GOTO SKIP_LOOP
     END
   END

  --Determining the data type of the column and depending on the data type, the VALUES part of
  --the INSERT statement is generated. Care is taken to handle columns with NULL values. Also
  --making sure, not to lose any data from flot, real, money, smallmomey, datetime columns
  SET @Actual_Values = @Actual_Values  +
  CASE 
   WHEN @Data_Type IN ('char','varchar','nchar','nvarchar') 
    THEN 
     'COALESCE('''''''' + REPLACE(RTRIM(' + @Column_Name + '),'''''''','''''''''''')+'''''''',''NULL'')'
   WHEN @Data_Type IN ('datetime','smalldatetime') 
    THEN 
     'COALESCE('''''''' + RTRIM(CONVERT(char,' + @Column_Name + ',109))+'''''''',''NULL'')'
   WHEN @Data_Type IN ('uniqueidentifier') 
    THEN  
     'COALESCE('''''''' + REPLACE(CONVERT(char(255),RTRIM(' + @Column_Name + ')),'''''''','''''''''''')+'''''''',''NULL'')'
   WHEN @Data_Type IN ('text','ntext') 
    THEN  
     'COALESCE('''''''' + REPLACE(CONVERT(char(8000),' + @Column_Name + '),'''''''','''''''''''')+'''''''',''NULL'')'     
   WHEN @Data_Type IN ('binary','varbinary') 
    THEN  
     'COALESCE(RTRIM(CONVERT(char,' + 'CONVERT(int,' + @Column_Name + '))),''NULL'')'  
   WHEN @Data_Type IN ('timestamp','rowversion') 
    THEN  
     CASE 
      WHEN @include_timestamp = 0 
       THEN 
        '''DEFAULT''' 
       ELSE 
        'COALESCE(RTRIM(CONVERT(char,' + 'CONVERT(int,' + @Column_Name + '))),''NULL'')'  
     END
   WHEN @Data_Type IN ('float','real','money','smallmoney')
    THEN
     'COALESCE(LTRIM(RTRIM(' + 'CONVERT(char, ' +  @Column_Name  + ',2)' + ')),''NULL'')' 
   ELSE 
    'COALESCE(LTRIM(RTRIM(' + 'CONVERT(char, ' +  @Column_Name  + ')' + ')),''NULL'')' 
  END   + '+' +  ''',''' + ' + '
  
  --Generating the column list for the INSERT statement
  SET @Column_List = @Column_List +  @Column_Name + ',' 

  SKIP_LOOP: --The label used in GOTO

  SELECT  @Column_ID = MIN(ORDINAL_POSITION) 
  FROM  INFORMATION_SCHEMA.COLUMNS (NOLOCK) 
  WHERE  TABLE_NAME = @table_name AND 
  ORDINAL_POSITION > @Column_ID AND
  (@owner IS NULL OR TABLE_SCHEMA = @owner)


 --Loop ends here!
 END

--To get rid of the extra characters that got concatenated during the last run through the loop
SET @Column_List = LEFT(@Column_List,len(@Column_List) - 1)
SET @Actual_Values = LEFT(@Actual_Values,len(@Actual_Values) - 6)

IF LTRIM(@Column_List) = '' 
 BEGIN
  RAISERROR('No columns to select. There should at least be one column to generate the output',16,1)
  RETURN -1 --Failure. Reason: Looks like all the columns are ommitted using the @cols_to_exclude parameter
 END

--Forming the final string that will be executed, to output the INSERT statements
IF (@include_column_list <> 0)
 BEGIN
  SET @Actual_Values = 
   'SELECT ' +  
   CASE WHEN @top IS NULL OR @top < 0 THEN '' ELSE ' TOP ' + LTRIM(STR(@top)) + ' ' END + 
   '''' + RTRIM(@Start_Insert) + 
   ' ''+' + '''(' + RTRIM(@Column_List) +  '''+' + ''')''' + 
   ' +''VALUES(''+ ' +  @Actual_Values  + '+'')''' + ' ' + 
   COALESCE(@from,' FROM ' + CASE WHEN @owner IS NULL THEN '' ELSE '[' + LTRIM(RTRIM(@owner)) + '].' END + '[' + rtrim(@table_name) + ']' + '(NOLOCK)')
 END
ELSE IF (@include_column_list = 0)
 BEGIN
  SET @Actual_Values = 
   'SELECT ' + 
   CASE WHEN @top IS NULL OR @top < 0 THEN '' ELSE ' TOP ' + LTRIM(STR(@top)) + ' ' END + 
   '''' + RTRIM(@Start_Insert) + 
   ' '' +''VALUES(''+ ' +  @Actual_Values + '+'')''' + ' ' + 
   COALESCE(@from,' FROM ' + CASE WHEN @owner IS NULL THEN '' ELSE '[' + LTRIM(RTRIM(@owner)) + '].' END + '[' + rtrim(@table_name) + ']' + '(NOLOCK)')
 END 

--Determining whether to ouput any debug information
IF @debug_mode =1
 BEGIN
  PRINT '/*****START OF DEBUG INFORMATION*****'
  PRINT 'Beginning of the INSERT statement:'
  PRINT @Start_Insert
  PRINT ''
  PRINT 'The column list:'
  PRINT @Column_List
  PRINT ''
  PRINT 'The SELECT statement executed to generate the INSERTs'
  PRINT @Actual_Values
  PRINT ''
  PRINT '*****END OF DEBUG INFORMATION*****/'
  PRINT ''
 END
  
PRINT '--INSERTs generated by ''sp_generate_inserts'' stored procedure written by Vyas'
PRINT '--Build number: 22'
PRINT '--Problems/Suggestions? Contact Vyas @ vyaskn@hotmail.com'
PRINT '--http://vyaskn.tripod.com'
PRINT ''
PRINT 'SET NOCOUNT ON'
PRINT ''


--Determining whether to print IDENTITY_INSERT or not
IF (@IDN <> '')
 BEGIN
  PRINT 'SET IDENTITY_INSERT ' + QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + QUOTENAME(@table_name) + ' ON'
  PRINT 'GO'
  PRINT ''
 END


IF @disable_constraints = 1 AND (OBJECT_ID(QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + @table_name, 'U') IS NOT NULL)
 BEGIN
  IF @owner IS NULL
   BEGIN
    SELECT  'ALTER TABLE ' + QUOTENAME(COALESCE(@target_table, @table_name)) + ' NOCHECK CONSTRAINT ALL' AS '--Code to disable constraints temporarily'
   END
  ELSE
   BEGIN
    SELECT  'ALTER TABLE ' + QUOTENAME(@owner) + '.' + QUOTENAME(COALESCE(@target_table, @table_name)) + ' NOCHECK CONSTRAINT ALL' AS '--Code to disable constraints temporarily'
   END

  PRINT 'GO'
 END

PRINT ''
PRINT 'PRINT ''Inserting values into ' + '[' + RTRIM(COALESCE(@target_table,@table_name)) + ']' + ''''


--All the hard work pays off here!!! You'll get your INSERT statements, when the next line executes!
EXEC (@Actual_Values)

PRINT 'PRINT ''Done'''
PRINT ''


IF @disable_constraints = 1 AND (OBJECT_ID(QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + @table_name, 'U') IS NOT NULL)
 BEGIN
  IF @owner IS NULL
   BEGIN
    SELECT  'ALTER TABLE ' + QUOTENAME(COALESCE(@target_table, @table_name)) + ' CHECK CONSTRAINT ALL'  AS '--Code to enable the previously disabled constraints'
   END
  ELSE
   BEGIN
    SELECT  'ALTER TABLE ' + QUOTENAME(@owner) + '.' + QUOTENAME(COALESCE(@target_table, @table_name)) + ' CHECK CONSTRAINT ALL' AS '--Code to enable the previously disabled constraints'
   END

  PRINT 'GO'
 END

PRINT ''
IF (@IDN <> '')
 BEGIN
  PRINT 'SET IDENTITY_INSERT ' + QUOTENAME(COALESCE(@owner,USER_NAME())) + '.' + QUOTENAME(@table_name) + ' OFF'
  PRINT 'GO'
 END

PRINT 'SET NOCOUNT OFF'


SET NOCOUNT OFF
RETURN 0 --Success. We are done!
END

GO

PRINT 'Created the procedure'
GO


--Turn system object marking off
EXEC master.dbo.sp_MS_upd_sysobj_category 2
GO

PRINT 'Granting EXECUTE permission on sp_generate_inserts to all users'
GRANT EXEC ON sp_generate_inserts TO public

SET NOCOUNT OFF
GO

PRINT 'Done'

Sunday, 8 November 2009

Dependency Properties

Dependency properties are one of the features that allow for extension in WPF.

“Windows Presentation Foundation (WPF) provides a set of services that can be used to extend the functionality of a common language runtime (CLR) property. Collectively, these services are typically referred to as the WPF property system. A property that is backed by the WPF property system is known as a dependency property.”

See http://msdn.microsoft.com/en-us/library/ms752914.aspx

The value of a normal .NET property is read or written directly from or to a field in a class. The value of a DependencyProperty is read or written by calling GetValue() or SetValue() inherited from the DependencyObject base class.

Values are not stored in a field but in a dictionary provided by DependencyObject. The key is the name of the property and the value is the value you want to set.

The advantages of dependency properties include:

  • Change notification
    • Dependency properties have a built-in change notification mechanism so by registering a callback in the property metadata you get notified when the value of the property has been changed. Actions can be triggered in response to this notification like:
      • re-rendering appropriate elements,
      • updating the layout,
      • refreshing data-binding etc.
      • Look-up property triggers.
  • Property value inheritance
    • The value of a dependency property is resolved by using a value resolution strategy (i.e. flowing values down the element tree). But:
      • Not every dependency property participates in property value inheritance.
      • There may be other high-priority sources setting the property value.
  • Support for multiple providers
    • Property value providers can independently attempt to set the value of a dependency property. To avoid chaos there i a defined value resolution strategy.
  • Reduced memory footprint
    • The default values are stored once within the dependency property.

See http://wpftutorial.net/DependencyProperties.html

Friday, 6 November 2009

XAML markup extensions

“Markup extensions are a XAML concept. In attribute syntax, curly braces ({ and }) indicate a markup extension usage. This usage directs the XAML processing to escape from the general treatment of attribute values as either a literal string or a directly string-convertible value.” (my italics)

See http://msdn.microsoft.com/en-us/library/ms752059.aspx

“When used to provide an attribute value, the syntax that distinguishes a markup extension to a XAML processor is the presence of the opening and closing curly braces ({ and }). The type of markup extension is then identified by the string token immediately following the opening curly brace.

When used in property element syntax, a markup extension is visually the same as any other element used to provide a property element value: a XAML element declaration that references the markup extension class as an element, enclosed within angle brackets (<>). ”

See http://msdn.microsoft.com/en-us/library/ms747254.aspx

XAML-defined markup extensions

There are a number of XAML extensions not specific to WPF. These are usually identified by the prefix x: which is an XML prefix used to map the XAML namespace.

Extension tag Description
x:Type Supplies the Type object for the named type. This is used most frequently in styles and templates.
x:Static Produces static values from value-type code entities that are not directly the type of a property's value, but can be evaluated to that type.
x:Null Specifies null as a value for a XAML property.
x:Array Provides support for creation of general arrays in XAML syntax, for cases where the collection support provided by base elements and control models is deliberately not used.

Nested extension syntax

Extensions can be nested. For example:

<Setter Property="Background"  Value="{DynamicResource {x:Static SystemColors.ControlBrushKey}}" />

{} Escape Sequence / Markup Extension

To escape curly braces precede with the {} escape sequence, especially where the first character of the property is an opening curly brace. For example:

<Setter Property="SomeProperty"  Value="{}{" />

The value of SomeProperty will be set to {.

“The {} escape sequence is frequently required when specifying an XML type that must include a namespace qualifier in a location where XAML markup extension might appear. This includes the beginning of an XAML attribute value, and within a markup extension, immediately after an equal-sign. The following example shows escapes for an XML namespace that appears at the beginning of a XAML attribute value.”

  <StackPanel.Resources>
    <DataTemplate DataType="{}{http://planetsNS}Planet" >
      <StackPanel Orientation="Horizontal">
        <TextBlock Width="100" Text="{Binding Path=Element[{http://planetsNS}DiameterKM].Value}" />
        <TextBlock Width="100" Text="{Binding Path=Attribute[Name].Value}" />
        <TextBlock Text="{Binding Path=Element[{http://planetsNS}Details].Value}" /> 
      </StackPanel>
    </DataTemplate>
  </StackPanel.Resources>

See http://msdn.microsoft.com/en-us/library/ms744986.aspx

Thursday, 5 November 2009

Fulltext catalogues

To identify the full text catalogues run the following SQL:
SELECT name 
FROM sys.fulltext_catalogs;
GO
Alternatively use the SQL Management Studio.
  • Go to Object Explorer and connect to your server.
  • Expand the Databases node and find the database in question.
  • Expand the Storage > Full Text Catalogues node.
  • Right-click on a catalogue name and select Properties.
Note that the Tables/Views page of the Full-Text Catalog Properties dialog box shows how the catalogue tracks changes (radio buttons at the bottom of the screen).

Common tasks

Rebuild
“Tells SQL Server to rebuild the entire catalog. When a catalog is rebuilt, the existing catalog is deleted and a new catalog is created in its place. All the tables that have full-text indexing references are associated with the new catalog. Rebuilding resets the full-text metadata in the database system tables.”
Reorganize
“Tells SQL Server to perform a master merge, which involves merging the smaller indexes created in the process of indexing into one large index. Merging the full-text index fragments can improve performance and free up disk and memory resources. If there are frequent changes to the full-text catalog, use this command periodically to reorganize the full-text catalog.
REORGANIZE also optimizes internal index and catalog structures.
Keep in mind that, depending on the amount of indexed data, a master merge may take some time to complete. Master merging a large amount of data can create a long running transaction, delaying truncation of the transaction log during checkpoint. In this case, the transaction log might grow significantly under the full recovery model. As a best practice, ensure that your transaction log contains sufficient space for a long-running transaction before reorganizing a large full-text index in a database that uses the full recovery model. For more information, see Managing the Size of the Transaction Log File.”

SQL command to run

You can trigger a rebuild or reorganisation using the following command:
ALTER FULLTEXT CATALOG catalog_name 
{ REBUILD [ WITH ACCENT_SENSITIVITY = { ON | OFF } ]
| REORGANIZE
| AS DEFAULT 
}
See http://msdn.microsoft.com/en-us/library/ms176095.aspx

Tuesday, 3 November 2009

Assembly resource URI format

I can never remember the URI format for resources embedded in assemblies.  So:

assembly://<assemblyname>/<namespace>/<resource>

The <namespace> part can include folder names separated from the base assembly namespace by dots (.). For example a Spring configuration file located in a SpringConfig folder for an application with a default namespace of Mail.Merge.Console would have a resource definition of:

assembly://Mail.Merge.Console/Mail.Merge.Console.SpringConfig/SpringDataAccess.xml