c# - Query Builder for DATE type -

i'm having problem query builder. have datagridview want filter through. want allow search "name, surname, date". here sql query

select exdate, exname, exsurname examines (exdate = @param1) , (exname = @param2) , (exsurname = @param3) 

and c# code 'call' query

private void button1_click(object sender, eventargs e) {     try     {         this.examinestableadapter.fillby(this.dbspindataset.examines, datetimepicker1.value, textbox2.text, textbox3.text);     }     catch (systemexception ex)     {         system.windows.forms.messagebox.show(ex.message);     } } 

in vs 2 errors saying:

"...project1.dbspindatasettableadapters.examinestableadapter, string, string, string)' has invalid arguments." "...cannot convert 'system.windows.forms.datetimepicker' 'string'."

i understand error don't know how solve it. query written in 'query builder' in projects dataset. went filter columns exdate, exname , exsurname , wrote ? (question mark). query builder automatically transferred above mentioned form "= @param1", "= @param2" , "= @param3".

i know can't treat datetime string don't know write filter column of query builder code work.

you have declare string variable, , work!

private void button1_click(object sender, eventargs e)    {       string your_string = datetimepicker1.value.tostring();       try       {           this.examinestableadapter.fillby(this.dbspindataset.examines, your_string, textbox2.text, textbox3.text);       }       catch (systemexception ex)       {         system.windows.forms.messagebox.show(ex.message);       }     }