我有一个DataTable,我想在DataTable上选择与文本框中的输入匹配的多个列。以下代码仅选择1列。
var result = from data in mDataTable.AsEnumerable ()
where data.Field<string>("Code") == txtCode.Text
select data.Field<string> ("Description");
foreach (var res in result) {
txtxDescription.Text = res.ToString ();
}
如何使用LINQ在DataTable上选择2个或更多列?
答案 0 :(得分:3)
为什么不选择完整行(DataRow
对象),然后从中获取所有必要的值?
var rows = mDataTable.AsEnumerable()
.Where(data => data.Field<string>("Code") == txtCode.Text);
foreach(DataRow r in rows)
{
txtxDescription.Text = r.Field<string>("Description");
}
另一种选择是将数据投射到匿名对象:
var result = from data in mDataTable.AsEnumerable ()
where data.Field<string>("Code") == txtCode.Text
select new
{
Description = data.Field<string> ("Description"),
Code = data.Field<string> ("Code")
};
foreach (var res in result)
{
// last value always replace `txtxDescription.Text` ??
txtxDescription.Text = res.Description;
txtxCode.Text = res.Code;
}
答案 1 :(得分:0)
public void GridviewBinding()
{
DataSet ds = new DataSet();
string constr = ConfigurationManager.ConnectionStrings["SQLMSDB"].ConnectionString;
string sql = "select * from tbl_users";
using (SqlConnection conn = new SqlConnection(constr))
{
using (SqlCommand cmd = new SqlCommand(sql))
{
cmd.Connection = conn;
using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
{
sda.Fill(ds);
gridviewcontrol.DataSource = ds;
gridviewcontrol.DataBind();
ViewState["GridViewBindingData"] = ds.Tables[0];
}
}
}
}
protected void btn_searching_Click(object sender, EventArgs e)
{
if (!String.IsNullOrEmpty(txt_search.Text.Trim().ToString()) || !String.IsNullOrWhiteSpace(txt_search.Text.Trim().ToString()))
{
DataTable dt = (DataTable)ViewState["GridViewBindingData"];
var dataRow = dt.AsEnumerable().Where(x => x.Field<dynamic>("UserName") == txt_search.Text);
DataTable dt2 = dataRow.CopyToDataTable<DataRow>();
gridviewcontrol.DataSource = dt2;
gridviewcontrol.DataBind();
}
else
{
GridviewBinding();
}
}