c# 将 sql 数据导出到 csv

Question

将我的数据从 sql 导出到 excel 时，它从第二行开始，而不是第一行。我想我已经将问题缩小到代码的 streamwriter 部分，但似乎无法找出问题所在！这是代码；

public static void ToCsv3(IDataReader myReader, string fileName, bool includeHeaderAsFirstRow)

    {
        const string Separator = ",";
        Stream s = File.Create(fileName + ".txt");
        StreamWriter streamWriter = new StreamWriter(s, Encoding.Unicode);


        StringBuilder sb = null;

        if (includeHeaderAsFirstRow)
        {
            sb = new StringBuilder();
            for (int index = 0; index < myReader.FieldCount; index++)
            {
                if (myReader.GetName(index) != null)
                    sb.Append(myReader.GetName(index));

                if (index < myReader.FieldCount - 1)
                    sb.Append(Separator);
            }
            streamWriter.WriteLine(sb.ToString());
        }
        int j = 0;
        while (myReader.Read())
        {
            sb = new StringBuilder();


            for (int index = 0; index < myReader.FieldCount - 1; index++)
            {


                if (!myReader.IsDBNull(index))
                {
                    string value = myReader.GetValue(index).ToString();
                    if (myReader.GetFieldType(index) == typeof(String))
                    {
                        if (value.IndexOf("\"") >= 0)
                            value = value.Replace("\"", "\"\"");
                        if (value.IndexOf(Separator) >= 0)
                            value = "\"" + value + "\"";
                    }
                    if (j != 0)
                    {
                        if (index == 0)
                        {
                            sb.Append(Environment.NewLine);
                        }
                    }
                    sb.Append(value);

                    j = j + 1;
                }


                if (index < myReader.FieldCount - 1)
                    sb.Append(Separator);

            }


           if (!myReader.IsDBNull(myReader.FieldCount - 1))
                sb.Append(myReader.GetValue(myReader.FieldCount).ToString().Replace(Separator, " "));


            streamWriter.Write(sb.ToString());
        }



        myReader.Close();
        streamWriter.Close();


    }

Answer 1

我宁愿将解决方案分解为创建 CSV 文件并将其保存到文件中：

public static IEnumerable<String> ToCsv(IDataReader reader, 
  Boolean includeHeaderAsFirstRow, 
  Char separator = ',',  
  Char quotation = '"') {

  if (null == reader)
    throw new ArgumentNullException("reader");

  String qt = quotation.ToString(); 

  StringBuilder Sb = new StringBuilder();

  if (includeHeaderAsFirstRow) {
    for (int i = 0; i < reader.FieldCount; ++i) {
      if (i > 0)
        Sb.Append(separator);

      String name = reader.GetName(i);

      if (name.Contains(separator) || name.Contains(quotation))
        name = qt + name.Replace(qt, qt + qt) + qt;

      Sb.Append(name);
    }

    yield return Sb.ToString();
  }

  while (reader.Read()) {
    Sb.Clear();

    for (int i = 0; i < reader.FieldCount; ++i) {
      if (i > 0)
        Sb.Append(separator);

      if (!reader.IsDBNull(i)) {
        String item = Convert.ToString(reader[i]);

        if (item.Contains(separator) || item.Contains(quotation))
          item = qt + item.Replace(qt, qt + qt) + qt;

        Sb.Append(item);
      }
    }

    yield return Sb.ToString();
  }
}

public static void CsvToFile(String fileName, 
  IDataReader reader, 
  Char separator = ',',  
  Char quotation = '"') {

  if (String.IsNullOrEmpty(Path.GetExtension(fileName)))
    fileName += ".txt"; // ".csv" looks better here

  File.WriteAllLines(fileName, ToCsv(reader, separator, quotation));
}

c# 将 sql 数据导出到 csv

c# exporting sql data to csv

c#

sql

csv

streamwriter