如何在C#中从数据表中删除一列
本文关键字:一列 删除 数据表 | 更新日期: 2023-09-27 18:29:25
我有这个代码:
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))
{
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数据表,然后导出到txt文件。我得到了由三列组成的结果:
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。我该怎么做?感谢
在这种情况下,最好的选择可能是一开始就不选择它。
如果您只是不想导出第二列,则不需要从表中删除该列,可以使用DataColumn.ColumnName
或DataColumn.Ordinal
(索引):
foreach (DataRow row in dt.Rows)
{
foreach (DataColumn column in dt.Columns)
{
if (column.Ordinal != 1)
{
//Add the Data rows.
txt += row[column.ColumnName].ToString() + "|";
}
}
//...
}
然而,如果你无论如何都想删除它:
dt.Columns.RemoveAt(1);