NPOI从数据库中调取数据直接导出到EXCEL中

关于NPOI

　　NPOI是POI项目的.NET版本，是由@Tony Qu(http://tonyqus.cnblogs.com/)等大侠基于POI开发的，可以从http://npoi.codeplex.com/下载到它的最新版本。它不使用Office COM组件(Microsoft.Office.Interop.XXX.dll)，不需要安装Microsoft Office，支持对Office 97-2003的文件格式，功能比较强大。更详细的说明请看作者的博客或官方网站。

　　它的以下一些特性让我相当喜欢：

　　支持对标准的Excel读写

　　支持对流(Stream)的读写 (而Jet OLEDB和Office COM都只能针对文件)

　　支持大部分Office COM组件的常用功能

　　性能优异 (相对于前面的方法)

　　使用简单，易上手

　　使用NPOI

　　本文使用的是它当前的最新版本1.2.4，此版本的程序集缩减至2个：NPOI.dll、Ionic.Zip.dll，直接引用到项目中即可。

　　对于我们开发者使用的对象主要位于NPOI.HSSF.UserModel空间下，主要有HSSFWorkbook、HSSFSheet、 HSSFRow、HSSFCell，对应的接口为位于NPOI.SS.UserModel空间下的IWorkbook、ISheet、IRow、 ICell，分别对应Excel文件、工作表、行、列。

　　简单演示一下创建一个Workbook对象，添加一个工作表，在工作表中添加一行一列：

操作示例代码

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.IO;
using NPOI.HSSF.UserModel;
using NPOI.SS.UserModel;
using System.Data;
using System.Data.SqlClient;
 
public partial class _Default : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        MemoryStream ms =  RenderToExcel(GetTable());
        string fileName = @"c:\2.xls";
        SaveToFile(ms,  fileName);
        Response.Write("成功");
    }
    public  MemoryStream RenderToExcel(DataTable table)
    {
        MemoryStream ms = new MemoryStream();
 
        using (table)
        {
            IWorkbook workbook = new HSSFWorkbook();
 
            ISheet sheet = workbook.CreateSheet();
 
            IRow headerRow = sheet.CreateRow();
 
            // handling header.
            foreach (DataColumn column in table.Columns)
                headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//If Caption not set, returns the ColumnName value
 
            // handling value.
            int rowIndex = ;
 
            foreach (DataRow row in table.Rows)
            {
                IRow dataRow = sheet.CreateRow(rowIndex);
 
                foreach (DataColumn column in table.Columns)
                {
                    dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());
                }
 
                rowIndex++;
            }
 
            workbook.Write(ms);
            ms.Flush();
            ms.Position = ;
        }
 
        return ms;
    }
    private void SaveToFile(MemoryStream ms, string fileName)
    {
        using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
        {
            byte[] data = ms.ToArray();
 
            fs.Write(data, , data.Length);
            fs.Flush();
 
            data = null;
        }
    }
    private DataTable GetTable()
    {
        SqlHelperXhf xhf = new SqlHelperXhf();
        string sql = "select calling_no '电话号码',starttime '时间' ,hname '楼盘名称' from [fc_freetel] a where hname<>'无'and a.id = (select min(id) from fc_freetel where calling_no=a.calling_no) order by hname,starttime desc";
 
        return xhf.ExecuteDataTable(sql);
 
    }
    private  DataTable GetTable(int hid)
    {
        SqlHelperXhf xhf = new SqlHelperXhf();
        string sql = "select calling_no '电话号码',starttime '时间' ,hname '楼盘名称' from [fc_freetel] a where hid=@hid and a.id = (select min(id) from fc_freetel where calling_no=a.calling_no) order by hname,starttime desc";
        SqlParameter paramer = new SqlParameter("@hid", hid);
        return xhf.ExecuteDataTable(sql,paramer);
 
    }
    private DataTable GetTable(int hid1,int hid2,int hid3)
    {
        SqlHelperXhf xhf = new SqlHelperXhf();
        string sql = "select calling_no '电话号码',starttime '时间' ,hname '楼盘名称' from [fc_freetel] a where hid=@hid1 or hid=@hid2 or hid=@hid3 and a.id = (select min(id) from fc_freetel where calling_no=a.calling_no) order by hname,starttime desc";
        SqlParameter [] paramers =
        {
            new SqlParameter("@hid1", hid1),
            new SqlParameter("@hid2", hid2),
            new SqlParameter("@hid3", hid3)
        };
        return xhf.ExecuteDataTable(sql, paramers);
 
    }
}

参考资料：

简单演示一下创建一个Workbook对象，添加一个工作表，在工作表中添加一行一列：

using NPOI.HSSF.UserModel;

using NPOI.SS.UserModel;

public class NPOIWrite

{

void CreateSheet()

{

IWorkbook workbook = new HSSFWorkbook();//创建Workbook对象

ISheet sheet = workbook.CreateSheet("Sheet1");//创建工作表

IRow row = sheet.CreateRow(0);//在工作表中添加一行

ICell cell = row.CreateCell(0);//在行中添加一列

cell.SetCellValue("test");//设置列的内容

}

相应的读取代码：

using System.IO;

using NPOI.HSSF.UserModel;

using NPOI.SS.UserModel;

public class NPOIRead

{

void GetSheet(Stream stream)

{

IWorkbook workbook = new HSSFWorkbook(stream);//从流内容创建Workbook对象

ISheet sheet = workbook.GetSheetAt(0);//获取第一个工作表

IRow row = sheet.GetRow(0);//获取工作表第一行

ICell cell = row.GetCell(0);//获取行的第一列

string value = cell.ToString();//获取列的值

}

使用NPOI导出

从DataTable读取内容来创建Workbook对象：

public static MemoryStream RenderToExcel(DataTable table)

{

MemoryStream ms = new MemoryStream();

using (table)

{

using (IWorkbook workbook = new HSSFWorkbook())

{

using (ISheet sheet = workbook.CreateSheet())

{

IRow headerRow = sheet.CreateRow(0);

// handling header.

foreach (DataColumn column in table.Columns)

headerRow.CreateCell(column.Ordinal).SetCellValue(column.Caption);//If Caption not set, returns the ColumnName value

// handling value.

int rowIndex = 1;

foreach (DataRow row in table.Rows)

{

IRow dataRow = sheet.CreateRow(rowIndex);

foreach (DataColumn column in table.Columns)

{

dataRow.CreateCell(column.Ordinal).SetCellValue(row[column].ToString());

}

rowIndex++;

}

workbook.Write(ms);

ms.Flush();

ms.Position = 0;

}

return ms;

}

如果看不惯DataTable，那么DataReader也行：

public static MemoryStream RenderToExcel(IDataReader reader)

{

MemoryStream ms = new MemoryStream();

using (reader)

{

using (IWorkbook workbook = new HSSFWorkbook())

{

using (ISheet sheet = workbook.CreateSheet())

{

IRow headerRow = sheet.CreateRow(0);

int cellCount = reader.FieldCount;

// handling header.

for (int i = 0; i < cellCount; i++)

{

headerRow.CreateCell(i).SetCellValue(reader.GetName(i));

}

// handling value.

int rowIndex = 1;

while (reader.Read())

{

IRow dataRow = sheet.CreateRow(rowIndex);

for (int i = 0; i < cellCount; i++)

{

dataRow.CreateCell(i).SetCellValue(reader[i].ToString());

}

rowIndex++;

}

workbook.Write(ms);

ms.Flush();

ms.Position = 0;

}

return ms;

}

以上代码把创建的Workbook对象保存到流中，可以通过以下方法输出到浏览器，或是保存到硬盘中：

static void SaveToFile(MemoryStream ms, string fileName)

{

using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))

{

byte[] data = ms.ToArray();

fs.Write(data, 0, data.Length);

fs.Flush();

data = null;

}

static void RenderToBrowser(MemoryStream ms, HttpContext context, string fileName)

{

if (context.Request.Browser.Browser == "IE")

fileName = HttpUtility.UrlEncode(fileName);

context.Response.AddHeader("Content-Disposition", "attachment;fileName=" + fileName);

context.Response.BinaryWrite(ms.ToArray());

}

使用NPOI导入

需要注意的是，sheet.LastRowNum = sheet.PhysicalNumberOfRows - 1，这里可能存在BUG：当没有数据或只有一行数据时sheet.LastRowNum为0，PhysicalNumberOfRows 表现正常。

这里读取流中的Excel来创建Workbook对象，并转换成DataTable：

static DataTable RenderFromExcel(Stream excelFileStream)

{

using (excelFileStream)

{

using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))

{

using (ISheet sheet = workbook.GetSheetAt(0))//取第一个表

{

DataTable table = new DataTable();

IRow headerRow = sheet.GetRow(0);//第一行为标题行

int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells

int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1

//handling header.

for (int i = headerRow.FirstCellNum; i < cellCount; i++)

{

DataColumn column = new DataColumn(headerRow.GetCell(i).StringCellValue);

table.Columns.Add(column);

}

for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)

{

IRow row = sheet.GetRow(i);

DataRow dataRow = table.NewRow();

if (row != null)

{

for (int j = row.FirstCellNum; j < cellCount; j++)

{

if (row.GetCell(j) != null)

dataRow[j] = GetCellValue(row.GetCell(j));

}

table.Rows.Add(dataRow);

}

return table;

}

或者是直接生成SQL语句来插入到数据库：

public static int RenderToDb(Stream excelFileStream, string insertSql, DBAction dbAction)

{

int rowAffected = 0;

using (excelFileStream)

{

using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))

{

using (ISheet sheet = workbook.GetSheetAt(0))//取第一个工作表

{

StringBuilder builder = new StringBuilder();

IRow headerRow = sheet.GetRow(0);//第一行为标题行

int cellCount = headerRow.LastCellNum;//LastCellNum = PhysicalNumberOfCells

int rowCount = sheet.LastRowNum;//LastRowNum = PhysicalNumberOfRows - 1

for (int i = (sheet.FirstRowNum + 1); i <= rowCount; i++)

{

IRow row = sheet.GetRow(i);

if (row != null)

{

builder.Append(insertSql);

builder.Append(" values (");

for (int j = row.FirstCellNum; j < cellCount; j++)

{

builder.AppendFormat("'{0}',", GetCellValue(row.GetCell(j)).Replace("'", "''"));

}

builder.Length = builder.Length - 1;

builder.Append(");");

}

if ((i % 50 == 0 || i == rowCount) && builder.Length > 0)

{

//每50条记录一次批量插入到数据库

rowAffected += dbAction(builder.ToString());

builder.Length = 0;

}

return rowAffected;

}

这里的Excel可能没有数据，所以可以加一个方法来检测：

public static bool HasData(Stream excelFileStream)

{

using (excelFileStream)

{

using (IWorkbook workbook = new HSSFWorkbook(excelFileStream))

{

if (workbook.NumberOfSheets > 0)

{

using (ISheet sheet = workbook.GetSheetAt(0))

{

return sheet.PhysicalNumberOfRows > 0;

}

return false;

}