Monday, January 12, 2009

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.

Wednesday, December 3, 2008

SQL2005 String functions

SQL 2005 String Functions

String Functions are used for manipulating string expression. 
(Pass strings using single quotes)

Len('') - Returns length of string.
select Len("Urgent Work") will return 11

Lower('') - Convert all characters to lowercase characters.
select Lower('Urgent Work') will return urgent work

Upper('') - Convert all characters to uppercase characters.
select Upper('Urgent Work') will return URGENT WORK

LTrim('') - Removes spaces from given character strings on left.
select LTrim(' Urgent Work') will return Urgent Work

LTrim & RTRIM & Trim donot remove tab or line feed character.
RTrim('') - Removes space from given character strings on right.
select LTrim('Urgent Work ')  returns Urgent Work

Trim('') - Removes spaces from given character strings from both left and right.
select LTrim(' Urgent Work ')  returns Urgent Work

SubString('') - Returns a part of string from original string.

SubString(character_expression, position, length)
position - specifies where the substring begins.
length - specifies the length of the substring as number of characters.
Example: select SubString('Urgent Work',1,6)  return "Urgent"

Replace('') - Replace the desired string within the original string.
Replace(character_expression, searchstring, replacementstring)
SearchString - string which you want to replace.
ReplaceString - new string which you want to replace with
select replace('Think Big To Achieve Big', 'Big', 'Small')

Original - Think Big To Achieve Big
Result - Think SmallTo Achieve Small

Right('') - extract particular characters from right part of given string expression.
select right('Think High To Achieve High',15) will return "To Achieve High"

This function will be helpful when you want particular characters from right part.
Example: Let say i have social security nos. and i want to extract last 4 digit of it.
select right('111-11-1111',4) will return 1111
select right('222-22-2222',4) will return 2222
select right('333-33-3333',4) will return 3333
select right('444-44-4444',4) will return 4444

Complete List of Web 2.0 APIs

Complete List of Web 2.0 APIs

http://programmableweb.com/apilist/bycat

Very useful.  Hope helps!