Select SQL using c# error can someone guide this one

Question

What I'm missing?
I've got error:

Sqlexception was unhandled by usercode

SqlConnection con = new SqlConnection(MyConnectionString);
SqlCommand objCmd;
con.Open();
SqlDataReader dtReader;
String strSQL;
strSQL = "SELECT * FROM " + DropDownList1.SelectedValue + "'";

objCmd = new SqlCommand(strSQL, con);
dtReader = objCmd.ExecuteReader();

//*** BindData to GridView ***//
GridView3.DataSource = dtReader;
GridView3.DataBind();

dtReader.Close();
dtReader = null;

What is the error and remove the typo " ' " from your query. — mybirthname, Feb 24 '15 at 04:03
what is the exception, not on which line. Remove the ' symbol from the query. — mybirthname, Feb 24 '15 at 04:06
Your code works fine, your query has problem. Remove the " ' " at the end of strSQL = "SELECT * FROM "+DropDownList1.SelectedValue+"'"; — mhan0125, Feb 24 '15 at 04:08
and how can i sent value at strSQL = "SELECT * FROM "+DropDownList1.SelectedValue+"'"; — Kane Smith Sillapasit, Feb 24 '15 at 04:09
Now , I got error at GridView3.DataSource = dtReader; GridView3.DataBind(); — Kane Smith Sillapasit, Feb 24 '15 at 04:13
thank you for help error this invalidOperationExceoption at gridview3.databind(); — Kane Smith Sillapasit, Feb 24 '15 at 04:25

itzmebibin · Accepted Answer · 2015-02-24T04:40:20.550

2

Try this ,

  strSQL = "SELECT * FROM " + DropDownList1.SelectedValue;

ie., just remove ' from the query string.

Then add the following code at the end.

GridView3.DataSource = dtReader;
GridView3.DataSourceID = String.Empty;
GridView3.DataBind();

edited Feb 24 '15 at 04:40

answered Feb 24 '15 at 04:15

itzmebibin

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i got error at gridview3.databind error MSG is invalidOperationException was unhandled by user code – Kane Smith Sillapasit Feb 24 '15 at 04:26
@KaneSmithSillapasit What are the values inside the DropDownList control? – abramlimpin Feb 24 '15 at 04:34
name of table string value – Kane Smith Sillapasit Feb 24 '15 at 04:41
1

thx it work GridView3.DataSource = dtReader; GridView3.DataSourceID = String.Empty; GridView3.DataBind(); – Kane Smith Sillapasit Feb 24 '15 at 04:43

score 0 · Answer 2 · edited Feb 24 '15 at 11:29

this code works now

  SqlConnection con = new SqlConnection(MyConnectionString);
SqlCommand objCmd;
con.Open();
SqlDataReader dtReader;
String strSQL;
strSQL = "SELECT * FROM " + DropDownList1.SelectedValue ;

objCmd = new SqlCommand(strSQL, con);
dtReader = objCmd.ExecuteReader();

GridView3.DataSource = dtReader;
GridView3.DataSourceID = String.Empty;
GridView3.DataBind(); 

dtReader.Close();
dtReader = null;

Select SQL using c# error can someone guide this one

2 Answers2