Database Error In Data Filter

Don’t know is it right place to ask or not, but I am having following issue:

Fatal error: Database error 1242: Subquery returns more than 1 row

Invalid SQL: SELECT EP.es_preadmissionid, EP.pre_name, (SELECT roll_no FROM es_sections_student ESS WHERE ESS.student_id=EP.es_preadmissionid ) AS ROLL_NO, (SELECT section_id FROM es_sections_student ESS WHERE ESS.student_id=EP.es_preadmissionid) AS SECTION FROM es_preadmission EP , es_preadmission_details EPD where EP.pre_status !=‘inactive’ AND EPD.es_preadmissionid=EP.es_preadmissionid AND EPD.pre_class=1 ORDER BY es_preadmissionid ASC in /home/content/16/9882416/html/ on line 136

Got this error while filtering data, it is returning more than one value as result. If help me