How to increase the size of a database (Enterprise Manager)

How to increase the size of a database (Enterprise Manager)

To increase the size of a database

Expand a server group, and then expand a server.

Expand Databases, right-click the database to increase, and then click Properties.

To increase the data space, click the General tab. To increase the transaction log space, click the Transaction Log tab.

To add a new file, click the next empty row and, in the File name column, enter the file name that will contain the additional space.

The file location is generated automatically and given the .ndf suffix for a database file, or an .ldf suffix for a transaction log file.

To change the default values provided in the File name, Location, Space allocated (MB), and Filegroup (not applicable for the transaction log) columns, click the cell to change and enter the new value.

For existing files, only the Space allocated (MB) value can be changed; the new value must be larger than the existing value.

To specify how the file should grow, select from these options:

To allow the currently selected file to grow as more data space is needed, select Automatically grow file.

To specify that the file should grow by fixed increments, select In megabytes and specify a value.

To specify that the file should grow by a percentage of the current file size, select By percent and specify a value.

To specify the file size limit, select from these options:

To allow the file to grow as much as necessary, select Unrestricted filegrowth.

To specify the maximum size to which the file should be allowed to grow, select Restrict filegrowth (MB) and specify a value.

Note  The maximum database size is determined by the amount of disk space available and the licensing limits determined by the version of SQL Server you are using.

How to Get Available space on Database

How to Get Available space on Database using a Dynamic Query:-

EXEC(N'USE ' + @dbname + N' select  [FILE_SIZE_MB] =

           convert(decimal(12,2),round(size/128.000,2)),

     [SPACE_USED_MB] =

           convert(decimal(12,2),round(fileproperty(name,''SpaceUsed'')/

128.000,2)),

     [FREE_SPACE_MB] =

           convert(decimal(12,2),round((size-

fileproperty(name,''SpaceUsed''))/128.000,2)),

     [DEVICE_NAME] = left(NAME,15)

from  dbo.sysfiles;')

Minus Keyword in SQL Server 2000

Minus Keyword in SQL Server 2000
Oracle supports "Minus" Keyword, but today suddenly when i tried to execute same in SQL Server it won't work. So, here is an alternate way to use "Minus" in SQL Server:-
Example:
Select City, Statefrom Employee Minus Select City, State from Customer
This will work fine with Oracle, but won't work with SQL Server. So alternate way to use "Minus" Keyword in SQL Server:-
Select City, Statefrom Employee Except Select City, State from Customer

Create A Comma Delimited List From a Column

Create A Comma Delimited List From a Column

Create Sample Data for Both Solutions

-- Suppress data loading messages SET NOCOUNT ON   -- Create Sample Data  CREATE TABLE TeamInfo    (  MemberID    int IDENTITY,       TeamID      int,        FirstName   varchar(50)    )   -- Load Sample Data INSERT INTO TeamInfo VALUES ( 1, 'Jim' ) INSERT INTO TeamInfo VALUES ( 1, 'Mary' ) INSERT INTO TeamInfo VALUES ( 1, 'Bob' ) INSERT INTO TeamInfo VALUES ( 2, 'Sue' ) INSERT INTO TeamInfo VALUES ( 2, 'Ralph' ) INSERT INTO TeamInfo VALUES ( 2, 'Ellen' ) INSERT INTO TeamInfo VALUES ( 3, 'Bill' ) INSERT INTO TeamInfo VALUES ( 3, 'Linda' )

create function -- SQL 2000, Retrieve desired data

-- With SQL 2000, we will create a User Defined Function to do the concatenation. -- While this solution can also be used with SQL Server 2005/SQL Server 2008,  -- the previous suggestion is more efficient.   CREATE FUNCTION dbo.fnMakeTeamList    (  @TeamID int  )    RETURNS varchar(1000) AS    BEGIN       DECLARE @TempTeam table          (  Firstname varchar(20)  )       DECLARE @TeamList varchar(1000)       SET @TeamList = ''       INSERT INTO @TempTeam          SELECT FirstName          FROM TeamInfo          WHERE TeamID = @TeamID       IF @@ROWCOUNT > 0          UPDATE @TempTeam             SET @TeamList = ( @TeamList + FirstName + ', ' )       RETURN substring( @TeamList, 1, ( len( @TeamList ) - 1 ))    END   -- Usage SELECT     TeamID,     MemberList = dbo.fnMakeTeamList( TeamId )  FROM TeamInfo  GROUP BY TeamID   -- Results TeamID     MemberList 1 Jim, Mary, Bob 2 Sue, Ralph, Ellen 3 Bill, LindaS

QL Server 2005 / SQL Server 2008 Solution

--Retrieve desired data SELECT    t1.TeamID,    MemberList = substring((SELECT ( ', ' + FirstName )                            FROM TeamInfo t2                            WHERE t1.TeamID = t2.TeamID                            ORDER BY                                TeamID,                               FirstName                            FOR XML PATH( '' )                           ), 3, 1000 )FROM TeamInfo t1 GROUP BY TeamID   -- Results TeamID     MemberList 1 Bob, Jim, Mary 2 Ellen, Ralph, Sue 3 Bill, Linda

ISNULL() and COALESCE()

ISNULL() and COALESCE()

In dealing with NULL values in SQL Server, the developer is often faced with the requirement to evaluate the content of a field, and when said field in null, return another value (or field). There are two functions in SQL Server which support this requirement: ISNULL() and COALESCE.()

ISNULL() accepts two parameters. The first is evaluated, and if the value is null, the second value is returned (regardless of whether or not it is null). The following queries will return the second parameter in both cases:

SELECT ISNULL(NULL, 1) --Returns 1 SELECT ISNULL(NULL, NULL) --Returns NULL 

COALESCE()

COALESCE() is a TSQL function which, like ISNULL, is built into SQL Server. Unlike ISNULL, COALESCE is also a part of the ANSI-92 SQL Standard. Coalesce returns the first non-null expression in a list of expressions. The list can contain two or more items, and each item can be of a different data type. The following are valid examples of COALESCE:

SELECT COALESCE(NULL, 1) --Returns 1   SELECT COALESCE(NULL, 3, NULL, 1) --Returns 3 

ISNULL vs. COALESCE

Whenever multiple methods exist for addressing a single problem, the inevitable question is: which method is better? There are a few differences between the two functions which make COALESCE come out on top more often than not:
- COALESCE is ANSI-92 compliant. In the event that you need to port your code to another RDBMS, COALESCE will not require rework.
- COALESCE accepts greater than two expressions, whereas ISNULL accepts only two. In order to compare three expressions with ISNULL, you would have to nest expressions:
SELECT ISNULL(ISNULL(Col1, Col2), Col3)
- ISNULL constrains the result of a comparison of parameterrs to the datatype of the first value. For example, the following query will produce some often undesirable results using ISNULL, however it will behave as expected with COALESCE:

DECLARE @Field1 char(3), @Field2 char(50) SET @Field2 = 'Some Long String'   SELECT ISNULL(@Field1, @Field2) --Returns 'Som' SELECT COALESCE(@Field1, @Field2) --Returns 'Some Long String' 

Note: In other situations, COALESCE will produce unexpected results. COALESCE by nature promotes it's arguments to the highest datatype among compatable arguments (arguments which are not explicitly case, and which aren't compatable, will of course throw an error). When using COALESCE on an integer and a datetime, in that order, COALESCE will cast the integer as a datetime. For example:
SELECT COALESCE(5, GETDATE())
Will not return 5, it will return 1900-01-06 00:00:00.000 (5 as a datetime).

Performance

For most purposes, ISNULL and COALESCE perform in an almost identical fashion. It is generally accepted that ISNULL is slightly quicker than COALESCE, but not sufficiently to outweigh it's inherent limitations. As with any performance related issue, if performance is a significant concern, write it both ways, and test!

SQL2008: Lock a Stored Procedure for Single Use Only

SQL2008: Lock a Stored Procedure for Single Use Only

Create a Custom Error Message, Designating an User assigned Error Number, starting at 50000, or higher, and a user designated Error Message.

USE Northwind GO   EXECUTE sp_addmessage     @msgnum   = 51001,     @severity = 16,     @msgtext  = N'Resource NOT Available',     @lang     = 'us_english',    @replace  = REPLACE

Create a Stored Procedure that Can be 'locked'

CREATE PROCEDURE dbo.Employees_U_LastName    (  @EmployeeID   int,       @LastName     varchar(20)    ) AS    BEGIN         SET TRANSACTION ISOLATION LEVEL REPEATABLE READ       BEGIN TRANSACTION         DECLARE @LockResult int         EXECUTE @LockResult = sp_getapplock           @Resource    = 'RepeatableRead_TRANSACTION',           @LockMode    = 'Exclusive',          @LockTimeout = 0              IF @LockResult <> 0             BEGIN                ROLLBACK TRANSACTION                RAISERROR ( 51001, 16, 1 )                RETURN             END            -- All code between the use of sp_getapplock above,          -- and sp_releaseapplock below will be restricted to           -- only one user at a time.              -- Ten Second delay for Demonstration Purposes          WAITFOR DELAY '00:00:10'          -- Remove these three lines for 'Normal' use            UPDATE Employees             SET LastName = @LastName             WHERE EmployeeID = @EmployeeID            EXECUTE sp_releaseapplock              @Resource = 'RepeatableRead_TRANSACTION'         COMMIT TRANSACTION      END  Demonstration

Open two separate Query Windows, and place the following code in one of the windows.
DO NOT Execute the code until both Query Windows are in place and connected to the database.

Query Window 1

   EXECUTE dbo.Employees_U_LastName       @EmployeeID = 1,       @LastName   = 'Davolio-Jones'         SELECT           EmployeeID,          LastName,          FirstName       FROM Employees       WHERE EmployeeID = 1 

Place the following code in Query window 2

Query Window 2

   EXECUTE dbo.Employees_U_LastName       @EmployeeID = 1,       @LastName   = 'Davolio'         SELECT           EmployeeID,          LastName,          FirstName       FROM Employees       WHERE EmployeeID = 1 

Execute the code in Query window 1, and then immediately execute the code in Query window 2.

Results in Query Window 2

Msg 51001, Level 16, State 1, Procedure Employees_U_LastName, Line 21 Resource NOT Available 

As you can see, it becomes possible to control code to single use only. 

Clean up the test environment

DROP PROCEDURE dbo.Employees_U_LastName 

Concurrency and Performance Considerations

Applications should capture the error, and handle appropriately, perhaps attempting to EXECUTE the query after a brief delay.

Finding the Last Occurrence of a Pattern in a String

When dealing with string data, one of the most useful Transact-SQL functions you can have in your toolbox is PATINDEX. Aside from it’s many creative uses (and there are quite a few), it allows you to search for an expression (including wildcard operators) within any valid SQL Server character type. It returns the position of the first occurrence of the pattern within the string, and returns zero (0) if the pattern is not found. As always, an example is worth 1000 bon mots:

SELECT PATINDEX('%c%', 'abcdefgabcdefga')

The above snippet returns 3, because the first instance of “c” within “abcdefgabcdefga” is at the third character.

On occasion, you may be required to find the last occurrence of the pattern rather than the first. This usually happens when you’re dealing with data from external systems, or when you’ve inherited custody of an inappropriately denormalized system (one where more than one “logical” data item has been stored in a single, concatenated field). I have the same requirement for my “mad science” series, so I developed a function to take care of it. Here it is:

CREATE FUNCTION dbo.REVERSEPATINDEX(@StringToFind    nvarchar(max),

                                  @StringToSearch nvarchar(max))

RETURNS bigint

AS

BEGIN

  --LastIndex will store the "previous" index of the pattern

  --while we search for the "next" index inside our string.

  DECLARE @LastIndex bigint, @NextIndex bigint


  --We will chop off the "searched" portion of our string

  --After each search iteration

  DECLARE @CurrentStringToSearch nvarchar(max)


  --Assign the value of the input parameter to @CurrentStringToSearch

  SET @CurrentStringToSearch = @StringToSearch


  --Grab the first occurrence, if it exists, using PATINDEX

  SET @NextIndex = PATINDEX(@StringToFind, @CurrentStringToSearch)

    
  --If we've found the pattern within the string, continue and find

  --subsequent occurrences until there are no more to find.

  WHILE @NextIndex > 0

  BEGIN

      --Add @NextIndex to @LastIndex, effectively storing within

      --@LastIndex the index of the occurence that we have just found,

      --based upon the original (non-truncated) string.

      SET @LastIndex = COALESCE(@LastIndex,0) + @NextIndex

    
      --Truncate @CurrentStringToSearch, removing the portion of the

      --string that we have already searched.

      SET @CurrentStringToSearch
          = RIGHT(@CurrentStringToSearch, LEN(@CurrentStringToSearch) - @NextIndex)

    
      --Find the NEXT occurence of the pattern in the remaining portion of

      --the string to search.

      SET @NextIndex = PATINDEX(@StringToFind, @CurrentStringToSearch)

  END


  --We will COALESCE @LastIndex and @NextIndex; @LastIndex will be NULL

  --if the pattern does not exist in the string (as the loop above will

  --never have been executed).

  RETURN  COALESCE(@LastIndex, @NextIndex)

END

GO

And to test:

SELECT dbo.REVERSEPATINDEX('%c%', 'abcdefgabcdefga')

Returns 10 – the correct answer, given that the last occurrence of “c” in “abcdefgabcdefga” is at the tenth character.

How do you find out all the IDENTITY columns of all the tables in a given database?

How do you find out all the IDENTITY columns of all the tables in a 

given database?

SELECT '[' + TABLE_SCHEMA + '].[' + TABLE_NAME + ']' AS [Table Name], COLUMN_NAME, DATA_TYPE

FROM INFORMATION_SCHEMA.COLUMNS

WHERE COLUMNPROPERTY(OBJECT_ID(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)), COLUMN_NAME, 'IsIdentity') = 1

AND OBJECTPROPERTY(OBJECT_ID(QUOTENAME(TABLE_SCHEMA) + '.' + QUOTENAME(TABLE_NAME)), 'IsMSShipped') = 0

Differences Between SQL Server 2000 and 2005

Feature	SQL Server 2000	SQL Server 2005
Server Programming Extensions	Limited to extended stored procedures, which are difficult to write and can impact the server stability.	The incorporation of the CLR into the relational engine allows managed code written in .NET languages to run. Different levels of security can protect the server from poorly written code.
T-SQL Error Handling	Limited to checking @@error, no much flexibility.	Addition of TRY/CATCH allows more mature error handling. More error_xx functions can gather additional information about errors.
T-SQL Language	SQL Language enhanced from previous versions providing strong data manipulation capabilities.	All the power of SQL Server 2000 with the addition of CTEs for complex, recursive problems, enhanced TOP capabilities, PIVOT/APPLY/Ranking functions, and ROW_NUMBER
Auditing	Limited support using triggers to audit changes.	Robust event handling with EVENT NOTIFICATIONS, the OUTPUT clauses, and DDL triggers.
Large Data Types	Limited to 8k for normal data without moving to TEXT datatypes. TEXT is hard to work with in programming environments.	Includes the new varchar(max) types that can store up to 2GB of data in a single column/row.
XML	Limited to transforming relational data into XML with SELECT statements, and some simple query work with transformed documents.	Native XML datatype, support for schemas and full XPATH/XQUERY querying of data.
ADO.NET	v1.1 of ADO.NET included enhancements for client development.	v2 has more features, including automatic failover for database mirroring, support for multiple active result sets (MARS), tracing of calls, statistics, new isolation levels and more.
Messaging	No messaging built into SQL Server.	Includes Service Broker, a full-featured asynchronous messaging system that has evolved from Microsoft Message Queue (MSMQ), which is integrated into Windows.
Reporting Services	An extremely powerful reporting environment, but a 1.0 product.	Numerous enhancements, run-time sorting, direct printing, viewer controls and an enhanced developer experience.
ETL	DTS is a very easy to use and intuitive tool. Limited capabilities for sources and transformations. Some constructs, such as loops, were very difficult to implement.	Integration Services is a true programming environment allowing almost any source of data to be used and many more types of transformations to occur. Very complex environment that is difficult for non-DBAs to use. Requires programming skills.
Full-Text Search	Workable solution, but limited in its capabilities. Cumbersome to work with in many situations.	More open architecture, allowing integration and plug-ins of third party extensions. Much more flexible in search capabilities.

Sql Split function

CREATE FUNCTION Split

(

     @StringToSplit varchar(2048),

     @Separator varchar(128)

)

RETURNS TABLE AS RETURN

WITH CTE AS

(

     SELECT 0 StartIndex, 1 EndIndex

     UNION ALL

     SELECT EndIndex, CHARINDEX(@Separator, @StringToSplit, EndIndex) + LEN(@Separator)

     FROM CTE

     WHERE EndIndex > StartIndex

)

SELECT

     SUBSTRING(@StringToSplit

                        , StartIndex

                        , CASE WHEN EndIndex > LEN(@Separator)

                                  THEN EndIndex-StartIndex-LEN(@Separator)

                                  ELSE LEN(@StringToSplit) - StartIndex + 1

                         END) String

     ,StartIndex StartIndex     

FROM CTE

WHERE StartIndex > 0

How to export GridView to PDF (ASP.NET)

How to export GridView to PDF (ASP.NET)

Recently I have been trying to generate some reports to PDF file format from ASP. NET2.0 application. There are a lot of open source PDF libraries out there that you can use to export to PDF such as iTextSharp, Gios PDF .NET Library and PDFSharp. You can go to this link to find out more open source PDF libraries in C#.

Later I will show you a working solution on how to export GridView to PDF by using one of the free libraries – iTextSharp.

ITextSharp is a port of the iText open source java library written entirely in C# for the .NET platform. It is a library that allows developers to extend the capabilities of their web server applications with dynamic PDF document generation and generate PDF file on the fly.

Before that, you need to download the iTextSharp library. Here is the download link.

Add in the iTextSharp.dll as a reference into your web application.

Here is my sample of code:

…
using iTextSharp.text;
using iTextSharp.text.pdf;

protected void Page_Load(object sender, EventArgs e)
{
  ExportToPDF();
}

private void ExportToPDF()
{
  Document document = new Document(PageSize.A4, 0, 0, 50, 50);
  System.IO.MemoryStream msReport = newSystem.IO.MemoryStream();

  try {
    // creation of the different writers
    PdfWriter writer = PdfWriter.GetInstance(document, msReport);

    // we add some meta information to the document
    document.AddAuthor("eJuly");
    document.AddSubject("Export to PDF");

    document.Open();

    iTextSharp.text.Table datatable = new iTextSharp.text.Table(7);

    datatable.Padding = 2;
    datatable.Spacing = 0;

    float[] headerwidths = { 6, 20, 32, 18, 8, 8, 8 };
    datatable.Widths = headerwidths;

    // the first cell spans 7 columns
    Cell cell = new Cell(new Phrase("System Users Report",FontFactory.GetFont(FontFactory.HELVETICA, 16,Font.BOLD)));
    cell.HorizontalAlignment = Element.ALIGN_CENTER;
    cell.Leading = 30;
    cell.Colspan = 7;
    cell.Border = Rectangle.NO_BORDER;
    cell.BackgroundColor = newiTextSharp.text.Color(System.Drawing.Color.Gray);
    datatable.AddCell(cell);

    // These cells span 2 rows
    datatable.DefaultCellBorderWidth = 1;
    datatable.DefaultHorizontalAlignment = 1;
    datatable.DefaultRowspan = 2;
    datatable.AddCell("No.");
    datatable.AddCell(new Phrase("Full Name",FontFactory.GetFont(FontFactory.HELVETICA, 14,Font.NORMAL)));
    datatable.AddCell("Address");
    datatable.AddCell("Telephone No.");

    // This cell spans the remaining 3 columns in 1 row
    datatable.DefaultRowspan = 1;
    datatable.DefaultColspan = 3;
    datatable.AddCell("Just Put Anything");

    // These cells span 1 row and 1 column
    datatable.DefaultColspan = 1;
    datatable.AddCell("Col 1");
    datatable.AddCell("Col 2");
    datatable.AddCell("Col 3");

    datatable.DefaultCellBorderWidth = 1;
    datatable.DefaultRowspan = 1;

    for (int i = 1; i < 20; i++) {
      datatable.DefaultHorizontalAlignment =Element.ALIGN_LEFT; 
      datatable.AddCell(i.ToString()); 
      datatable.AddCell("This is my name."); 
      datatable.AddCell("I have a very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very, very long long address."); 
      datatable.AddCell("0123456789"); 

      datatable.DefaultHorizontalAlignment =Element.ALIGN_CENTER;
      datatable.AddCell("No"); 
      datatable.AddCell("Yes"); 
      datatable.AddCell("No"); 
    } 

    document.Add(datatable); 
  } 
  catch (Exception e) { 
    Console.Error.WriteLine(e.Message); 
  } 

  // we close the document 
  document.Close(); 

  Response.Clear(); 
  Response.AddHeader("content-disposition", "attachment;filename=Export.pdf"); 
  Response.ContentType = "application/pdf"; 
  Response.BinaryWrite(msReport.ToArray()); 
  Response.End(); 
}

Hope these codes can help those people who are new to asp.net developing and save some time on their searching solutions. You can also find the tutorial of iTextSharp at here.

Import Data from Excel File to sql datatable

Import Data from Excel File to sql datatableTo Export Data Form an Excel file, there is one drawback lying behind them. The Sheet1 from the query actually is the name of the spreadsheet in your excel file. What if there is no Sheet1 inside the excel file? What if you don’t even know the sheet name? 

Yes. I found this error when I tried to upload an excel file with different sheet name. And here is the solution for that.

To get the sheet name in your excel file, firstly, Microsoft DAO 3.5 Library is needed. Go to Project -> Reference -> Add Reference, select Microsoft DOA 3.5 Library from the list and add to your project. Here is the example code of how to get the first sheet in the excel file.

Dim strConn As String
Dim da As OleDbDataAdapter
Dim ds As New DataSet
Dim dao_dbE As dao.DBEngine
Dim dao_DB As DAO.Database
Dim strSheet As String

dao_dbE = New dao.DBEngine
dao_DB = dao_dbE.OpenDatabase("C:\test.xls", False, True, "Excel 8.0;")
strSheet = dao_DB.TableDefs(0).Name
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" & _ 
"Data Source=C:\test.xls;Extended Properties=""Excel 8.0;"""

da = New OleDbDataAdapter("SELECT * FROM [" & _
strSheet & "]", strConn)
da.TableMappings.Add("Table", "Excel")
da.Fill(ds)

Import Data from Excel File to sql datatable

Import Data from Excel File to sql datatable

As I has stated in my previous post regarding to Export Data Form an Excel file, there is one drawback lying behind them. The Sheet1 from the query actually is the name of the spreadsheet in your excel file. What if there is no Sheet1 inside the excel file? What if you don’t even know the sheet name? 

Yes. I found this error when I tried to upload an excel file with different sheet name. And here is the solution for that.

To get the sheet name in your excel file, firstly, Microsoft DAO 3.5 Library is needed. Go to Project -> Reference -> Add Reference, select Microsoft DOA 3.5 Library from the list and add to your project. Here is the example code of how to get the first sheet in the excel file.

Dim strConn As String
Dim da As OleDbDataAdapter
Dim ds As New DataSet
Dim dao_dbE As dao.DBEngine
Dim dao_DB As DAO.Database
Dim strSheet As String

dao_dbE = New dao.DBEngine
dao_DB = dao_dbE.OpenDatabase("C:\test.xls", False, True, "Excel 8.0;")
strSheet = dao_DB.TableDefs(0).Name
strConn = "Provider=Microsoft.Jet.OLEDB.4.0;" & _ 
"Data Source=C:\test.xls;Extended Properties=""Excel 8.0;"""

da = New OleDbDataAdapter("SELECT * FROM [" & _
strSheet & "]", strConn)
da.TableMappings.Add("Table", "Excel")
da.Fill(ds)

Export Datatable to Excel

Export Datatable to Excel(Not HTML Tables)

Recently I working with export data to an excel file, but had faced a lot of problems. The main problem of it: The exported file is saved as HTML tables with XLS extension, not the actual XLS format. In this way, I can’t re-import the data using the OleDbConnection.

I have been searching around the net, but no exact solution that suit my situation. Finally, I had found another way to export data into the actual XLS format, by using Excel.Application.

First thing that you need to do is to add Excel dll (Microsoft Excel 11.0 Object Library) as a reference.

Here are the codes.

Private Function ExportToExcel(ByVal dt As System.Data.DataTable)
    Dim xlsApp As New Excel.Application
    Dim xlsWorkbook As Excel.Workbook
    Dim xlsWorksheets As Excel.Worksheets
    Dim xlsWorksheet As Excel.Worksheet
    Dim strhdr As String
    Dim row As Integer
    Dim drow As DataRow
    Dim strFile As String = "test.xls"
    Dim filename As String = Server.MapPath("Doc") & "\" & strFile

    If dt.Rows.Count > 0 Then
        'Create new workbook
        xlsWorkbook =
        xlsApp.Workbooks.Add

        'Get the first worksheet
        xlsWorksheet = CType(xlsWorkbook.Worksheets(1), Excel.Worksheet)

        'Activate current worksheet
        xlsWorksheet.Activate()

        'Set header row to row 1
        row = 1

        'Add table headers to worksheet
        xlsWorksheet.Cells(row,1).Value = "NAME"
        xlsWorksheet.Cells(row, 2).Value = "JOB POSITION"
        xlsWorksheet.Cells(row, 3).Value = "ORIGIN"

        'Format header row (bold, extra row height, autofit
width)
        With xlsWorksheet.Range("A" & row, "C" & row)
            .Font.Bold = True
            .Rows(row).RowHeight = 1.5 * xlsWorksheet.StandardHeight
            .EntireRow.AutoFit()
        End With

        'Freeze the column headers
        With xlsWorksheet.Range("A" & row + 1, "C" & row + 1).Select
            xlsApp.ActiveWindow.FreezePanes = True
        End With

        'Write data to Excel worksheet
        For Each drow In dt.Rows
            row += 1
            If Not IsDBNull(dr.Item("NAME")) Then xlsWorksheet.Cells(row, 1).Value = dr.Item("NAME")
            If Not IsDBNull(dr.Item("JOB POSITION")) Then xlsWorksheet.Cells(row, 2).Value = dr.Item("JOB POSITION")
            If Not IsDBNull(dr.Item("ORIGIN")) Then xlsWorksheet.Cells(row, 3).Value =
dr.Item("ORIGIN")
        Next

        'Format data rows (align to top, autofit width and height)
        With xlsWorksheet.Range("A2", "C" & row)
            .VerticalAlignment = CType(XlVAlign.xlVAlignCenter, Excel.XlVAlign)
            .HorizontalAlignment = CType(XlHAlign.xlHAlignLeft, Excel.XlHAlign)
            .EntireColumn.AutoFit()
            .EntireRow.AutoFit()
        End With

        'Make excel workbook visible to user after all data has been added to worksheet
        xlsApp.DisplayAlerts = False
        xlsWorkbook.Close(True, filename)

        'Export data to client machine
        strhdr = "attachment;filename=" & strFile
        With Response
            .Clear()
            .ContentType = "application/vnd.ms-excel"
            .ContentEncoding = System.Text.Encoding.Default
            .AppendHeader("Content-Disposition", strhdr)
            .WriteFile(filename)
            .Flush()
            .Clear()
            .Close()
        End With
    End If
End Function

Difference between NVARCHAR and VARCHAR in SQL Server

Difference between NVARCHAR and VARCHAR in SQL Server

The broad range of data types in SQL Server can sometimes throw people through a loop, especially when the data types seem to be highly interchangeable. Two in particular that constantly spark questions areVARCHAR and NVARCHAR: what's the difference between the two, and how important is the difference?

VARCHAR is an abbreviation for variable-length character string. It's a string of text characters that can be as large as the page size for the database table holding the column in question. The size for a table page is 8,196 bytes, and no one row in a table can be more than 8,060 characters. This in turn limits the maximum size of a VARCHAR to 8,000 bytes.

The "N" in NVARCHAR means uNicode. Essentially, NVARCHAR is nothing more than a VARCHAR that supports two-byte characters. The most common use for this sort of thing is to store character data that is a mixture of English and non-English symbols — in my case, English and Japanese.

The key difference between the two data types is how they're stored. VARCHAR is stored as regular 8-bit data. But NVARCHAR strings are stored in the database as UTF-16 — 16 bits or two bytes per character, all the time — and converted to whatever codepage is being used by the database connection on output (typically UTF-8). That said, NVARCHAR strings have the same length restrictions as their VARCHAR cousins — 8,000 bytes. However, since NVARCHARs use two bytes for each character, that means a given NVARCHAR can only hold 4,000 characters (not bytes) maximum. So, the amount of storage needed for NVARCHAR entities is going to be twice whatever you'd allocate for a plain old VARCHAR.

Because of this, some people may not want to use NVARCHAR universally, and may want to fall back on VARCHAR — which takes up less space per row — whenever possible.

Here's an example of how to mix and match the use of the two types. Let's say we have a community website where people log in with a username, but can also set a public "friendly" name to be more easily identified by other users. The login name can be a VARCHAR, which means it must be 8-bit ASCII (and it can be constrained further to conventional alphanumerics with a little more work, typically on the front end). The friendly name can be an NVARCHAR to allow Unicode entities. This way you're allowing support for Unicode, but only in the place where it matters most — both for the users, and where the extra storage space is going to be put to the best possible use.

VARCHAR and NVARCHAR in SQL Server 2005

One fairly major change to both VARCHAR and NVARCHAR in SQL Server 2005 is the creation of the VARCHAR(MAX) and NVARCHAR(MAX) data types. If you create a VARCHAR(MAX) column, it can hold up to 2^31 bytes of data, or 2,147,483,648 characters; NVARCHAR(MAX) can hold 2^30 bytes, or 1,073,741,823 characters.

These new data types are essentially replacements for the Large Object or LOB data types such as TEXT and NTEXT, which have a lot of restrictions. They can't be passed as variables in a stored procedure, for instance. The(MAX) types don't have those restrictions; they just work like very large string types. Consequently, if you're in the process of re-engineering an existing data design for SQL Server 2005, it might make sense to migrate some (although not all!) TEXT / NTEXT fields to VARCHAR(MAX) / NVARCHAR(MAX) types when appropriate.

The big difference between VARCHAR and NVARCHAR is a matter of need. If you need Unicode support for a given data type, either now or soon enough, go with NVARCHAR. If you're sticking with 8-bit data for design or storage reasons, go with VARCHAR. Note that you can always migrate from VARCHAR to NVARCHAR at the cost of some room -- but you can't go the other way 'round. Also, because NVARCHAR involves fetching that much more data, it may prove to be slower depending on how many table pages must be retrieved for any given operation.