C# 如何在C中从datatable中删除一列?
我有以下代码:C# 如何在C中从datatable中删除一列?,c#,sql-server,asp.net-mvc,datatable,C#,Sql Server,Asp.net Mvc,Datatable,我有以下代码: public ActionResult RcColdis() { string constr = @"Data Source=192.168.52.197,1433;Network Library=DBMSSOCN;Initial Catalog=DB_ADRIAN;User ID=adrian;Password=password;"; using (SqlConnection con = new SqlConnection(constr)) {
public ActionResult RcColdis() {
string constr = @"Data Source=192.168.52.197,1433;Network Library=DBMSSOCN;Initial Catalog=DB_ADRIAN;User ID=adrian;Password=password;";
using (SqlConnection con = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand("select a.secCode, b.[Haircut (%)],c.[Absolute IDR (Miliar)] from openquery(PDC_MYAPPS,'select secCode from mii.secReq')a left join (select * from RC_Saham)b on a.secCode=b.kode left join (select * from Absolute_IDR)c on b.kode=c.[Kode Saham]where b.[Haircut (%)] is not null union select a.code_Ic,a. PERC_HRCT, case a. PERC_HRCT when 100 then 20 end from openquery(MANTARAY,'select b.code_ic, a.PERC_HRCT from cminstruments a, instrument_codes b where a.ID_CMI_CAPCO = b.INS_ID_INS_CAPCO')a left join (select * from Absolute_IDR)b on a.code_Ic = b.[Kode Saham]where code_Ic in (select a.secCode from openquery(PDC_MYAPPS,'select secCode from mii.secReq')a left join (select * from RC_Saham )b on a.secCode=b.kode left join (select * from Absolute_IDR)c on b.kode = c.[Kode Saham] where c.[Absolute IDR (Miliar)] is null )"))
{
using (SqlDataAdapter sda = new SqlDataAdapter())
{
cmd.Connection = con;
sda.SelectCommand = cmd;
using (DataTable dt = new DataTable())
{
sda.Fill(dt);
//Build the Text file data.
string txt = string.Empty;
//Add new line.
foreach (DataRow row in dt.Rows)
{
foreach (DataColumn column in dt.Columns)
{
//Add the Data rows.
txt += row[column.ColumnName].ToString() + "|";
}
//Add new line.
txt += "\r\n";
}
//Download the Text file.
Response.Clear();
Response.Buffer = true;
Response.AddHeader("content-disposition", "attachment;filename=SqlExport.txt");
Response.Charset = "";
Response.ContentType = "application/text";
Response.Output.Write(txt);
Response.Flush();
Response.End();
}
}
}
}
return View("Index");
}
它将数据从数据库导出到datatable,然后导出txt文件。我得到的结果由三列组成:
asdas |2312|12312|
asdas |2312|12312|
sdgs |2312|12312|
assdfs|2312|12312|
assdfs|2312|12312|
我不想在txt文件中显示第二列。我怎么做?谢谢在这种情况下,最好的选择可能是一开始就不要选择它 如果不想导出第二列,则不需要从表中删除该列,可以使用DataColumn.ColumnName或DataColumn.Ordinalindex: 但是,如果仍要删除它,请执行以下操作:
dt.Columns.RemoveAt(1);
那么在你的查询中不选择它?@Dion V我需要选择它作为参考,以获取第三列中的数据。太好了!它起作用了。非常感谢。顺便说一句,如果我想在上面两列之间添加行值都为10的新列,怎么样?不客气。但是我不明白你的新要求。您想添加具有哪些值的新列?也许你应该问另一个问题。
dt.Columns.RemoveAt(1);