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(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; } private 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; } } 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：
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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：
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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：
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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：
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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：
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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：
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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：
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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：
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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;} |
