+ SELECT t1.id AS registerNo, CONCAT(SUBSTRING(t2.name,1,1),t2.id) AS realName,t3.grade_id AS gradeSerialNo,CONCAT(SUBSTRING(t2.name,1,1),t2.id) AS alias,t2.gender,t2.id AS extendId FROM base_student t1
+ INNER JOIN xjr_user t2 ON t1.user_id = t2.id
+ INNER JOIN base_student_school_roll t3 ON t1.user_id = t3.user_id
+ WHERE t1.delete_mark = 0 AND t2.delete_mark = 0
+ AND t1.student_id IS NOT NULL AND t1.student_id != ''