Install NuGet.Tools according to Visual Studio version
Website: https://www.nuget.org/downloads
2. Tools→NuGet Package Manager→Package Manager Console
Title 3. Enter "Install-Package NPOI" and press Enter
4. At this time, you will find that there are more NPOI-related references in the "References" under the project.
Export table from database
class NPIOExcel
{
/// <summary>
/// 导出表格
/// </summary>
/// <param name="data">要导出的表格</param>
/// <param name="fileName">导出文件名带路径</param>
public static void OutPutExcel(DataTable data,string fileName)
{
string sheetName = "测试数据";
//创建一个工作簿对象
IWorkbook workBook = new HSSFWorkbook();
//创建一个工作表的实例
ISheet sheet = string.IsNullOrEmpty(sheetName) ? workBook.CreateSheet("sheet1") : workBook.CreateSheet(sheetName);
int rowIndex = 0;
if (data.Columns.Count > 0)
{
IRow header = sheet.GetRow(rowIndex); //创建第一行
//设置列名
if (header == null)
{
header = sheet.CreateRow(rowIndex);
}
for (int i = 0; i < data.Columns.Count; i++)
{
ICell cell = header.CreateCell(i); //创建单元格
cell.SetCellValue(data.Columns[i].ColumnName);//设置单元格的值
}
}
//添加数据
if (data.Rows.Count > 0)
{
for (int i = 0; i < data.Rows.Count; i++)
{
rowIndex++;
IRow row = sheet.CreateRow(rowIndex);
for (int j = 0; j < data.Columns.Count; j++)
{
ICell cell = row.CreateCell(j);//创建单元格
cell.SetCellValue(data.Rows[i][j].ToString()); //设置值
}
}
}
for (int i = 0; i < data.Rows.Count; i++)
{
sheet.AutoSizeColumn(i);
}
using (FileStream fs = new FileStream(fileName, FileMode.Create, FileAccess.Write))
{
workBook.Write(fs); //写入指定的路径 创建excel文件
}
}
Import the contents of a certain Excel sheet into DataTable, and then import the database in batches through DataTable.
/// <summary>
/// Excel某sheet中内容导入到DataTable中
/// 区分xsl和xslx分别处理
/// </summary>
/// <param name="filePath">Excel文件路径,含文件全名</param>
/// <returns></returns>
public static DataTable ExcelSheetImportToDataTable(string filePath)
{
DataTable dt = new DataTable();
IWorkbook hssfworkbook;
if (Path.GetExtension(filePath).ToLower() == ".xls".ToLower())
{
//.xls
#region .xls文件处理:HSSFWorkbook
try
{
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
hssfworkbook = new HSSFWorkbook(file);
}
}
catch (Exception e)
{
throw e;
}
//ISheet sheet = hssfworkbook.GetSheet(sheetName);//Excel的名称
ISheet sheet = hssfworkbook.GetSheetAt(0);
System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
HSSFRow headerRow = (HSSFRow)sheet.GetRow(0); //第一行也就是字段名
//第二行最后一个方格的编号 即总的列数
for (int j = 0; j < (sheet.GetRow(1).LastCellNum); j++)
{
//设置每一列的名字
HSSFCell cell = (HSSFCell)headerRow.GetCell(j);
dt.Columns.Add(cell.ToString());
}
while (rows.MoveNext())
{
IRow row = (HSSFRow)rows.Current;
DataRow dr = dt.NewRow();
if (row.RowNum == 0) continue;//第一行为标题，不需要导入
for (int i = 0; i < row.LastCellNum; i++)
{
if (i >= dt.Columns.Count)//每条记录的单元格数量不能大于表格栏位数量
{
break;
}
ICell cell = row.GetCell(i);
if ((i == 0) && (string.IsNullOrEmpty(cell.ToString()) == true))//每行第一个cell为空,break
{
break;
}
if (cell == null)
{
dr[i] = null;
}
else
{
dr[i] = cell.ToString();
}
}
dt.Rows.Add(dr);
}
#endregion
}
else
{
//.xlsx
#region .xlsx文件处理:XSSFWorkbook
try
{
using (FileStream file = new FileStream(filePath, FileMode.Open, FileAccess.Read))
{
hssfworkbook = new XSSFWorkbook(file);
}
}
catch (Exception e)
{
throw e;
}
//ISheet sheet = hssfworkbook.GetSheet(sheetName);//Excel的名称
ISheet sheet = hssfworkbook.GetSheetAt(0);
System.Collections.IEnumerator rows = sheet.GetRowEnumerator();
XSSFRow headerRow = (XSSFRow)sheet.GetRow(1);
//一行最后一个方格的编号 即总的列数
for (int j = 0; j < (sheet.GetRow(1).LastCellNum); j++)
{
//设置每一列的名字
XSSFCell cell = (XSSFCell)headerRow.GetCell(j);
dt.Columns.Add(cell.ToString());
}
while (rows.MoveNext())
{
IRow row = (XSSFRow)rows.Current;
DataRow dr = dt.NewRow();
if (row.RowNum == 0) continue;//第一行标题，不需要导入
for (int i = 0; i < row.LastCellNum; i++)
{
if (i >= dt.Columns.Count) //每条记录的单元格数量不能大于表格栏位数量
{
break;
}
ICell cell = row.GetCell(i);
if ((i == 0) && (string.IsNullOrEmpty(cell.ToString()) == true))//每行第一个cell为空,break
{
break;
}
if (cell == null)
{
dr[i] = null;
}
else
{
dr[i] = cell.ToString();
}
}
dt.Rows.Add(dr);
}
#endregion
}
return dt;
}
}
Batch insert database method
#region SqlBulkCopyByDatatable 表中资料批量插入到数据库
/// <summary>
/// 将表中资料批量插入到数据库
/// 转自：
/// </summary>
/// <param name="connectionString"></param>
/// <param name="TableName"></param>
/// <param name="dt"></param>
public static void SqlBulkCopyByDatatable(string connectionString, string TableName, DataTable dt)
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
using (SqlBulkCopy sqlbulkcopy =
new SqlBulkCopy(connectionString, SqlBulkCopyOptions.UseInternalTransaction))
{
try
{
sqlbulkcopy.DestinationTableName = TableName;
for (int i = 0; i < dt.Columns.Count; i++)
{
sqlbulkcopy.ColumnMappings.Add(dt.Columns[i].ColumnName, dt.Columns[i].ColumnName);
}
sqlbulkcopy.WriteToServer(dt);
}
catch (System.Exception ex)
{
throw ex;
}
}
}
}
#endregion