날짜 검색시 date_format() 쓰면 인덱스 안탐
$date_condition .= ($date_condition ? ' and ' : '') . "( (A.cs_inflow_date BETWEEN '".$step_sdate." 00:00:00' AND '".$step_edate." 23:59:59') OR (A.cs_join_date BETWEEN '".$step_sdate." 00:00:00' AND '".$step_edate." 23:59:59') OR (A.cs_join_deposit_date BETWEEN '".$step_sdate." 00:00:00' AND '".$step_edate." 23:59:59'))";
