Question

我正在将.csv文件的内容导入数据表中。此.csv没有列名，这导致第一行数据成为列。我怎么能阻止这个？

我使用string sql_select = "select * from [" + filetable + "]"作为我的命令，我想我可以使用：

DECLARE @tableName [sysname]
SET @tableName = '[" + filetable + "]'

DECLARE @sql [nvarchar](MAX)
SELECT TOP 11 @sql = ISNULL(@sql + ', ', '') + [name] FROM [sys].[all_columns] WHERE OBJECT_ID(@tableName) = [object_id]
ORDER BY [column_id]
SET @sql = 'SELECT ' + @sql + ' FROM ' + @tableName

EXEC (@sql)

要将列数限制为11，之前已添加了列名。

但我无法让它工作，因为预期的OleDbCommand是SELECT。

无论哪种方式，是否可以使用dbDataAdapter.Fill(DataTable);仅填充行而不是列？

Answer 1

在SO上有很多类似的问题/答案可以帮助你解决这个问题。这个method看起来非常有用，请看一下。

首先确保您引用：

using System.Data;
using System.Data.OleDb;
using System.Globalization;
using System.IO;

这是方法，记得在调用它时将isFirstRowHeader设置为false：

static DataTable GetDataTableFromCsv(string path, bool isFirstRowHeader)
{
    string header = isFirstRowHeader ? "Yes" : "No";

    string pathOnly = Path.GetDirectoryName(path);
    string fileName = Path.GetFileName(path);

    string sql = @"SELECT * FROM [" + fileName + "]";

    using(OleDbConnection connection = new OleDbConnection(
              @"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + pathOnly + 
              ";Extended Properties=\"Text;HDR=" + header + "\""))
    using(OleDbCommand command = new OleDbCommand(sql, connection))
    using(OleDbDataAdapter adapter = new OleDbDataAdapter(command))
    {
        DataTable dataTable = new DataTable();
        dataTable.Locale = CultureInfo.CurrentCulture;
        adapter.Fill(dataTable);
        return dataTable;
    }
}

如果这对您没有帮助，请告诉我，我会找到另一种方式。祝你好运！

Answer 2

我在下面写了五种方法。

它们的设计考虑了可选的引号（例如＆＃34;符号），并且在不使用其他库的情况下尽可能多样化：

    public static DataTable GetDataTabletFromCSVFile(string filePath, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            using (TextFieldParser TextFieldParser = new TextFieldParser(filePath))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    public static DataTable GetDataTableFromCsvString(string csvBody, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            MemoryStream MemoryStream = new MemoryStream();


            StreamWriter StreamWriter = new StreamWriter(MemoryStream);

            StreamWriter.Write(csvBody);

            StreamWriter.Flush();


            MemoryStream.Position = 0;


            using (TextFieldParser TextFieldParser = new TextFieldParser(MemoryStream))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    public static DataTable GetDataTableFromRemoteCsv(string url, bool isHeadings)
    {
        DataTable MethodResult = null;
        try
        {
            HttpWebRequest httpWebRequest = (HttpWebRequest)WebRequest.Create(url);
            HttpWebResponse httpWebResponse = (HttpWebResponse)httpWebRequest.GetResponse();

            StreamReader StreamReader = new StreamReader(httpWebResponse.GetResponseStream());

            using (TextFieldParser TextFieldParser = new TextFieldParser(StreamReader))
            {
                if (isHeadings)
                {
                    MethodResult = GetDataTableFromTextFieldParser(TextFieldParser);

                }
                else
                {
                    MethodResult = GetDataTableFromTextFieldParserNoHeadings(TextFieldParser);

                }

            }

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }


    private static DataTable GetDataTableFromTextFieldParser(TextFieldParser textFieldParser)
    {
        DataTable MethodResult = null;
        try
        {
            textFieldParser.SetDelimiters(new string[] { "," });

            textFieldParser.HasFieldsEnclosedInQuotes = true;


            string[] ColumnFields = textFieldParser.ReadFields();

            DataTable dt = new DataTable();

            foreach (string ColumnField in ColumnFields)
            {
                DataColumn DataColumn = new DataColumn(ColumnField);

                DataColumn.AllowDBNull = true;

                dt.Columns.Add(DataColumn);

            }


            while (!textFieldParser.EndOfData)
            {
                string[] Fields = textFieldParser.ReadFields();


                for (int i = 0; i < Fields.Length; i++)
                {
                    if (Fields[i] == "")
                    {
                        Fields[i] = null;

                    }

                }

                dt.Rows.Add(Fields);

            }

            MethodResult = dt;

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

    private static DataTable GetDataTableFromTextFieldParserNoHeadings(TextFieldParser textFieldParser)
    {
        DataTable MethodResult = null;
        try
        {
            textFieldParser.SetDelimiters(new string[] { "," });

            textFieldParser.HasFieldsEnclosedInQuotes = true;

            bool FirstPass = true;

            DataTable dt = new DataTable();

            while (!textFieldParser.EndOfData)
            {
                string[] Fields = textFieldParser.ReadFields();

                if(FirstPass)
                {
                    for (int i = 0; i < Fields.Length; i++)
                    {
                        DataColumn DataColumn = new DataColumn("Column " + i);

                        DataColumn.AllowDBNull = true;

                        dt.Columns.Add(DataColumn);

                    }

                    FirstPass = false;

                }

                for (int i = 0; i < Fields.Length; i++)
                {
                    if (Fields[i] == "")
                    {
                        Fields[i] = null;

                    }

                }

                dt.Rows.Add(Fields);

            }

            MethodResult = dt;

        }
        catch (Exception ex)
        {
            ex.HandleException();
        }
        return MethodResult;
    }

如果像我一样，您从报告服务中保存，那么您应该像这样使用它：

    Warning[] warnings;
    string[] streamids;
    string mimeType;
    string encoding;
    string filenameExtension;

    byte[] bytes = rvMain.ServerReport.Render("csv", null, out mimeType, out encoding, out filenameExtension, out streamids, out warnings);

    string CsvBody = System.Text.Encoding.UTF8.GetString(bytes);

    DataTable dt = GetDataTableFromCsvString(CsvBody,true);

否则，您只需要：

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTableFromCsvString(CsvBody, IsHeadings);

或直接从csv文件中使用

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTabletFromCsvFile(FilePath, IsHeadings)

或者使用远程存储的csv文件

    bool IsHeadings = true; //Does the data include a heading row?

    DataTable dt = GetDataTabletFromRemoteCsv(Url, IsHeadings)

从.csv文件导入DataTable时遇到麻烦

2 个答案: