将Excel表格读入DataTable的最佳/最快方式？

Question

我在这里希望有人可以点我在正确的方向 - 我试图创建一个相当强大的实用程序来读取一个Excel工作表中的数据(可能的.xls或.xlsx)到一个DataTable尽快和瘦削如可能.

我在VB中想出了这个例程(尽管我对C#答案很满意):

Public Shared Function ReadExcelIntoDataTable(ByVal FileName As String, ByVal SheetName As String) As DataTable
    Dim RetVal As New DataTable

    Dim strConnString As String
    strConnString = "Driver={Microsoft Excel Driver (*.xls, *.xlsx, *.xlsm, *.xlsb)};DBQ=" & FileName & ";"

    Dim strSQL As String 
    strSQL = "SELECT * FROM [" & SheetName & "$]"

    Dim y As New Odbc.OdbcDataAdapter(strSQL, strConnString)

    y.Fill(RetVal)

    Return RetVal

End Function

我想知道这是否是最好的方法,或者是否有更好/更有效的方式(或者只是更智能的方式 - 也许Linq /本地.Net提供商)来代替使​​用？

另外,只是一个快速而愚蠢的附加问题 - 我是否需要包含诸如y.Dispose()和/ y = Nothing或将要处理的代码,因为变量应该在例程结束时死掉,对吧？

谢谢!!

Answer 1

如果你想在C#中基于Ciarán答案做同样的事情

string sSheetName = null;
string sConnection = null;
DataTable dtTablesList = default(DataTable);
OleDbCommand oleExcelCommand = default(OleDbCommand);
OleDbDataReader oleExcelReader = default(OleDbDataReader);
OleDbConnection oleExcelConnection = default(OleDbConnection);

sConnection = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\\Test.xls;Extended Properties=\"Excel 12.0;HDR=No;IMEX=1\"";

oleExcelConnection = new OleDbConnection(sConnection);
oleExcelConnection.Open();

dtTablesList = oleExcelConnection.GetSchema("Tables");

if (dtTablesList.Rows.Count > 0) 
{
    sSheetName = dtTablesList.Rows[0]["TABLE_NAME"].ToString();
}

dtTablesList.Clear();
dtTablesList.Dispose();


if (!string.IsNullOrEmpty(sSheetName)) {
    oleExcelCommand = oleExcelConnection.CreateCommand();
    oleExcelCommand.CommandText = "Select * From [" + sSheetName + "]";
    oleExcelCommand.CommandType = CommandType.Text;
    oleExcelReader = oleExcelCommand.ExecuteReader();
    nOutputRow = 0;

    while (oleExcelReader.Read())
    {
    }
    oleExcelReader.Close();
}
oleExcelConnection.Close();

这是另一种方法将Excel读入DataTable而不使用OLEDB非常快速请记住,文件ext必须是.CSV才能正常工作

private static DataTable GetDataTabletFromCSVFile(string csv_file_path)
{
    csvData = new DataTable(defaultTableName);
    try
    {
        using (TextFieldParser csvReader = new TextFieldParser(csv_file_path))
        {
            csvReader.SetDelimiters(new string[]
            {
                tableDelim 
            });
            csvReader.HasFieldsEnclosedInQuotes = true;
            string[] colFields = csvReader.ReadFields();
            foreach (string column in colFields)
            {
                DataColumn datecolumn = new DataColumn(column);
                datecolumn.AllowDBNull = true;
                csvData.Columns.Add(datecolumn);
            }

            while (!csvReader.EndOfData)
            {
                string[] fieldData = csvReader.ReadFields();
                //Making empty value as null
                for (int i = 0; i < fieldData.Length; i++)
                {
                    if (fieldData[i] == string.Empty)
                    {
                        fieldData[i] = string.Empty; //fieldData[i] = null
                    }
                    //Skip rows that have any csv header information or blank rows in them
                    if (fieldData[0].Contains("Disclaimer") || string.IsNullOrEmpty(fieldData[0]))
                    {
                        continue;
                    }
                }
                csvData.Rows.Add(fieldData);
            }
        }
    }
    catch (Exception ex)
    {
    }
    return csvData;
}

Answer 2

我一直都习惯OLEDB这样,像...

    Dim sSheetName As String
    Dim sConnection As String
    Dim dtTablesList As DataTable
    Dim oleExcelCommand As OleDbCommand
    Dim oleExcelReader As OleDbDataReader
    Dim oleExcelConnection As OleDbConnection

    sConnection = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:\Test.xls;Extended Properties=""Excel 12.0;HDR=No;IMEX=1"""

    oleExcelConnection = New OleDbConnection(sConnection)
    oleExcelConnection.Open()

    dtTablesList = oleExcelConnection.GetSchema("Tables")

    If dtTablesList.Rows.Count > 0 Then
        sSheetName = dtTablesList.Rows(0)("TABLE_NAME").ToString
    End If

    dtTablesList.Clear()
    dtTablesList.Dispose()

    If sSheetName <> "" Then

        oleExcelCommand = oleExcelConnection.CreateCommand()
        oleExcelCommand.CommandText = "Select * From [" & sSheetName & "]"
        oleExcelCommand.CommandType = CommandType.Text

        oleExcelReader = oleExcelCommand.ExecuteReader

        nOutputRow = 0

        While oleExcelReader.Read

        End While

        oleExcelReader.Close()

    End If

    oleExcelConnection.Close()

该ACE.OLEDB供应商将同时读取.xls和.xlsx文件,我一直觉得速度相当不错.

Answer 3

public DataTable ImportExceltoDatatable(string filepath)
{
    // string sqlquery= "Select * From [SheetName$] Where YourCondition";
    string sqlquery = "Select * From [SheetName$] Where Id='ID_007'";
    DataSet ds = new DataSet();
    string constring = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + filepath + ";Extended Properties=\"Excel 12.0;HDR=YES;\"";
    OleDbConnection con = new OleDbConnection(constring + "");
    OleDbDataAdapter da = new OleDbDataAdapter(sqlquery, con);
    da.Fill(ds);
    DataTable dt = ds.Tables[0];
    return dt;
}

Answer 4

您可以将 OpenXml SDK 用于 *.xlsx 文件。它的工作速度非常快。我为这个 sdk 做了简单的 C# IDataReader 实现。看这里。现在您可以轻松地将 Excel 文件读取到 DataTable 中，并且可以将 Excel 文件导入到 SQL Server 数据库中（使用 SqlBulkCopy）。ExcelDataReader 读取速度非常快。在我的机器上，10000 条记录不到 3 秒，60000 条记录不到 8 秒。

读取数据表示例：

class Program
{
    static void Main(string[] args)
    {
        var dt = new DataTable();
        using (var reader = new ExcelDataReader(@"data.xlsx"))
            dt.Load(reader);

        Console.WriteLine("done: " + dt.Rows.Count);
        Console.ReadKey();
   }
}

Answer 5

这对我来说似乎很好。

private DataTable ReadExcelFile(string sheetName, string path)
{

    using (OleDbConnection conn = new OleDbConnection())
    {
        DataTable dt = new DataTable();
        string Import_FileName = path;
        string fileExtension = Path.GetExtension(Import_FileName);
        if (fileExtension == ".xls")
            conn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + Import_FileName + ";" + "Extended Properties='Excel 8.0;HDR=YES;'";
        if (fileExtension == ".xlsx")
            conn.ConnectionString = "Provider=Microsoft.ACE.OLEDB.12.0;Data Source=" + Import_FileName + ";" + "Extended Properties='Excel 12.0 Xml;HDR=YES;'";
        using (OleDbCommand comm = new OleDbCommand())
        {
            comm.CommandText = "Select * from [" + sheetName + "$]";
            comm.Connection = conn;
            using (OleDbDataAdapter da = new OleDbDataAdapter())
            {
                da.SelectCommand = comm;
                da.Fill(dt);
                return dt;
            }
        }
    }
}