Question

我需要从数据库导出大量数据到excel。我已经创建了一种从select中导出数据的方法。但是我设法创建了一个新的Excel。不更新现有的。我已经在互联网上进行搜索，但无法理解自己在做什么错。

这是该方法的代码：

public static void ExportDSToExcel(DataSet ds, string destination)
    {
        using (var workbook = SpreadsheetDocument.Open(destination, true))
        {
            //var workbookPart = workbook.AddWorkbookPart();
            workbook.WorkbookPart.Workbook = new DocumentFormat.OpenXml.Spreadsheet.Workbook();
            workbook.WorkbookPart.Workbook.Sheets = new DocumentFormat.OpenXml.Spreadsheet.Sheets();

            uint sheetId = 1;

            foreach (DataTable table in ds.Tables)
            {
                var sheetPart = workbook.WorkbookPart.AddNewPart<WorksheetPart>();
                var sheetData = new DocumentFormat.OpenXml.Spreadsheet.SheetData();
                sheetPart.Worksheet = new DocumentFormat.OpenXml.Spreadsheet.Worksheet(sheetData);

                DocumentFormat.OpenXml.Spreadsheet.Sheets sheets = workbook.WorkbookPart.Workbook.GetFirstChild<DocumentFormat.OpenXml.Spreadsheet.Sheets>();
                string relationshipId = workbook.WorkbookPart.GetIdOfPart(sheetPart);

                if (sheets.Elements<DocumentFormat.OpenXml.Spreadsheet.Sheet>().Count() > 0)
                {
                    sheetId =
                        sheets.Elements<DocumentFormat.OpenXml.Spreadsheet.Sheet>().Select(s => s.SheetId.Value).Max() + 1;
                }

                DocumentFormat.OpenXml.Spreadsheet.Sheet sheet = new DocumentFormat.OpenXml.Spreadsheet.Sheet() { Id = relationshipId, SheetId = sheetId, Name = table.TableName };
                sheets.Append(sheet);

                DocumentFormat.OpenXml.Spreadsheet.Row headerRow = new DocumentFormat.OpenXml.Spreadsheet.Row();

                List<String> columns = new List<string>();
                foreach (DataColumn column in table.Columns)
                {
                    columns.Add(column.ColumnName);

                    DocumentFormat.OpenXml.Spreadsheet.Cell cell = new DocumentFormat.OpenXml.Spreadsheet.Cell();
                    cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
                    cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(column.ColumnName);
                    headerRow.AppendChild(cell);
                }

                sheetData.AppendChild(headerRow);

                foreach (DataRow dsrow in table.Rows)
                {
                    DocumentFormat.OpenXml.Spreadsheet.Row newRow = new DocumentFormat.OpenXml.Spreadsheet.Row();
                    foreach (String col in columns)
                    {
                        DocumentFormat.OpenXml.Spreadsheet.Cell cell = new DocumentFormat.OpenXml.Spreadsheet.Cell();
                        cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
                        cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(dsrow[col].ToString()); //
                        newRow.AppendChild(cell);
                    }

                    sheetData.AppendChild(newRow);
                }
            }

这是我调用方法的地方：

string _oracleConnection = "Data Source=XXXXX;Persist Security Info=True;User ID=XXXXXX;Password=YYYYY";

        OracleConnection con = new OracleConnection(_oracleConnection);
        using (con = new OracleConnection(_oracleConnection))
        {
            using (OracleCommand cmd = new OracleCommand())
            {
                cmd.Connection = con;
                cmd.CommandType = CommandType.Text;

                 cmd.CommandText = "SELECT connect_by_root proj_catg_name, parent_proj_catg_id,LTRIM(SYS_CONNECT_BY_PATH (proj_catg_short_name, '-'),'-') id_path, proj_catg_name FROM pcatval start with  proj_catg_name in ('XXXXXXXXXXXXX', 'XXXXXXXXXXXXXX') CONNECT BY PRIOR proj_catg_id = parent_proj_catg_id ";

                con.Open();
                DataSet ds = new System.Data.DataSet();
                OracleDataAdapter oda = new OracleDataAdapter(cmd);
                oda.Fill(ds);
                string destination = @"D:\TEST.xlsx";
                P_IAP.Excelfile.ExportDSToExcel(ds, destination);
            }

            Excelfile excelfile = new Excelfile();

您知道我应该更改什么吗？可以说我想更新一个名为TEST的Excel文件和一个名为Sheet1的工作表

Answer 1

要通过OpenXml修改Excel文件并再次保存，您应该使用其流来打开它：

byte[] ByteArrayContent = File.ReadAllBytes(path);
using (MemoryStream mStream = new MemoryStream())
{
    stream.Write(ByteArrayContent , 0, (int)ByteArrayContent .Length);
    using (SpreadsheetDocument workbook = SpreadsheetDocument.Open(mStream , true))
    {
       uint sheetId = 1;

        foreach (DataTable table in ds.Tables)
        {
            var sheetPart = workbook.WorkbookPart.AddNewPart<WorksheetPart>();
            var sheetData = new DocumentFormat.OpenXml.Spreadsheet.SheetData();
            sheetPart.Worksheet = new DocumentFormat.OpenXml.Spreadsheet.Worksheet(sheetData);

            DocumentFormat.OpenXml.Spreadsheet.Sheets sheets = workbook.WorkbookPart.Workbook.GetFirstChild<DocumentFormat.OpenXml.Spreadsheet.Sheets>();
            string relationshipId = workbook.WorkbookPart.GetIdOfPart(sheetPart);

            if (sheets.Elements<DocumentFormat.OpenXml.Spreadsheet.Sheet>().Count() > 0)
            {
                sheetId =
                    sheets.Elements<DocumentFormat.OpenXml.Spreadsheet.Sheet>().Select(s => s.SheetId.Value).Max() + 1;
            }

            DocumentFormat.OpenXml.Spreadsheet.Sheet sheet = new DocumentFormat.OpenXml.Spreadsheet.Sheet() { Id = relationshipId, SheetId = sheetId, Name = table.TableName };
            sheets.Append(sheet);

            DocumentFormat.OpenXml.Spreadsheet.Row headerRow = new DocumentFormat.OpenXml.Spreadsheet.Row();

            List<String> columns = new List<string>();
            foreach (DataColumn column in table.Columns)
            {
                columns.Add(column.ColumnName);

                DocumentFormat.OpenXml.Spreadsheet.Cell cell = new DocumentFormat.OpenXml.Spreadsheet.Cell();
                cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
                cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(column.ColumnName);
                headerRow.AppendChild(cell);
            }

            sheetData.AppendChild(headerRow);

            foreach (DataRow dsrow in table.Rows)
            {
                DocumentFormat.OpenXml.Spreadsheet.Row newRow = new DocumentFormat.OpenXml.Spreadsheet.Row();
                foreach (String col in columns)
                {
                    DocumentFormat.OpenXml.Spreadsheet.Cell cell = new DocumentFormat.OpenXml.Spreadsheet.Cell();
                    cell.DataType = DocumentFormat.OpenXml.Spreadsheet.CellValues.String;
                    cell.CellValue = new DocumentFormat.OpenXml.Spreadsheet.CellValue(dsrow[col].ToString()); //
                    newRow.AppendChild(cell);
                }

                sheetData.AppendChild(newRow);
            }
        }
    }
    File.WriteAllBytes(SaveAsPath, mStream.ToArray()); 
}

它也回答了here

使用OpenXML和C＃更新现有的Excel工作表

1 个答案: