I am getting the following error while trying to filter record in Database.

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/products.projectdesk.info/s-erp/office_admin/includes/classes/developer.mysql.class.php*on line 136

Can anybody help me out in solving above error that why is it occuring????
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