Asp.Net Core 导入Excel数据到Sqlite数据库并重新导出到Excel

Asp.Net Core 导入Excel数据到Sqlite数据库并重新导出到Excel

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在博文“在Asp.Net Core 使用 Sqlite 数据库”中创建了ASP.NET Core Web 应用程序，并讲解如何配置并使用Sqlite 数据库。

博文“ASP.NET Core导入导出Excel文件”中讲解了如何导入及导出Excel数据文件，实现Excel文件的导入导出功能，但导入后仅把数据呈现在页面上，并未保存至数据库。本文讲述如何将Excel文件写入Sqlite数据库。

修改OnPostImport方法为如下内容：

        private Prize prize ;

        public async Task<IActionResult> OnPostImportAsync(IFormFile excelFile)
        {
            ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
            string sWebRootFolder = _webHostEnvironment.WebRootPath;
            string sFileName = $"{Guid.NewGuid()}.xlsx";
            FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
            try
            {
                using (FileStream fs = new FileStream(file.ToString(), FileMode.Create))
                {
                    excelFile.CopyTo(fs);
                    fs.Flush();
                }
                using(ExcelPackage package = new ExcelPackage(file))
                {
                    StringBuilder sb = new StringBuilder();
                    ExcelWorksheet worksheet = package.Workbook.Worksheets[0];
                    int rowCount = worksheet.Dimension.Rows;
                    int colCount = worksheet.Dimension.Columns;
                    //bool bheaderRow = true;
                    for(int row = 2; row <= rowCount; row++)
                    {
                        prize = new Prize
                        {
                            prizeid = worksheet.Cells[row, 1].Value.ToString(),
                            prizename = worksheet.Cells[row, 2].Value.ToString(),
                            point = Convert.ToInt32(worksheet.Cells[row, 3].Value),
                            number = Convert.ToInt32(worksheet.Cells[row, 4].Value),
                            totalpoint = Convert.ToInt64(worksheet.Cells[row, 5].Value)
                        };
                        _context.Prizes.Add(prize);
                    }
                    await _context.SaveChangesAsync();
                    return Page();
                }
            }
            catch(Exception ex)
            {
                return Content(ex.Message);
            }
        }

导入方法为异步方法，获取Excel文件数据后，遍历每一行，把Excel表格数据与Prize模型数据一一对应，并添加到数据上下文。

下图为Excel数据表格：

运行程序，选择excel文件后，点击 导入按钮。

导入后，数据库中出现数据，如下图：

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将Sqlite数据库中的数据导出Excel

修改OnPostExport方法，如下：

   public IActionResult OnPostExport()
        {
            string sWebRootFolder = _webHostEnvironment.WebRootPath;
            string sFileName = $"{Guid.NewGuid()}.xlsx";
            FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
            ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
            using (ExcelPackage package=new ExcelPackage(file))
            {
                //add worksheet
                ExcelWorksheet workSheet = package.Workbook.Worksheets.Add("AspNetCore");

                workSheet.Cells.LoadFromCollection(_context.Prizes, true);

                package.Save();
            }

            return File(sFileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

运行程序，点击导出按钮，即可将数据全部导出到Excel。

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 只导出Totalpoint最大的5条记录

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修改OnPostExport方法，实现只导出totalpoint最大的5条记录：

 public IActionResult OnPostExport()
        {
            var query = from m in _context.Prizes
                        orderby m.totalpoint descending
                        select m;

            string sWebRootFolder = _webHostEnvironment.WebRootPath;
            string sFileName = $"{Guid.NewGuid()}.xlsx";
            FileInfo file = new FileInfo(Path.Combine(sWebRootFolder, sFileName));
            ExcelPackage.LicenseContext = LicenseContext.NonCommercial;
            using (ExcelPackage package=new ExcelPackage(file))
            {
                //add worksheet
                ExcelWorksheet workSheet = package.Workbook.Worksheets.Add("AspNetCore");

                workSheet.Cells.LoadFromCollection(query.Take(5), true);

                package.Save();
            }

            return File(sFileName, "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet");
        }

首先要对数据库查询记录进行排序；

var query = from m in _context.Prizes
                        orderby m.totalpoint descending
                        select m;

然后只取5条记录：

workSheet.Cells.LoadFromCollection(query.Take(5), true);

完成后导出的数据如下：

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