asp.net - C# SqlDataReader No data exists for the row/column -

i've been away programming while i've got need it.

i have problem sql datareader using sql server compact edition 4.0 (vs2012 built-in).

string connstring = "data source=c:\\..(path here)..\\vacationsdb.sdf"; sqlceconnection conn = new sqlceconnection(connstring); string strsql = "select * vacation vacationno = @val";  using (sqlcecommand cmd = new sqlcecommand(strsql, conn)) {     //read search value from text field     cmd.parameters.addwithvalue("@val", vacationno_txt.text);     conn.open();      sqlcedatareader reader = cmd.executereader();     fname_txt.text = reader.getstring(0);     mname_txt.text = reader.getstring(1);     /*      * .. snip      */     vacationno_txt.text = reader.getstring(11);     conn.close(); } 

i keep getting error: "invalidoperationexception unhandled. no data exists row/column." , error points @ fname_txt.text = reader.getstring(0);

but there data there because "submit" button it's code working , i've checked in database table itself.

any tips? thank you.

datareaders start out before first row.

to read first row, call read() once.
if there no first row, read() return false.