select
vtb.ID,
vtb.USER_ID,
vtb.T_USER_NAME,
vtb.T_EMAIL,
vtb.USER_ID_CARD,
vtb.UNIVERSITY_ID,
vtb.UNIVERSITY_ACADEMY,
vtb.UNIVERSITY_TITLE,
vtb.MASTER_MENTOR,
vtb.DOCTOR_MENTOR,
vtb.T_POSITION,
vtb.TEACHINGAGE,
vtb.TOP_EDUCATION,
vtb.T_GENDER,
vtb.T_BIRTHDAY,
vtb.T_MOBILEPHONE,
vtb.AREA_ID,
vtb.BIG_IMAGE_URL,
vtb.SMALL_IMAGE_URL,
vtb.PERSONAL_HOME_URL,
vtb.MAILING_ADDRESS,
vtb.OFFICE_ADDRESS,
vtb.MSG_FROM,
vtb.ADDTIME,
vtb.DELETESTATUS,
vtb.T_QQ,
vtb.ADMIN_ID,
vtb.T_E_NAME,
vtb.T_E_SURNAME,
vtb.T_B_INTEGRITY,
vtb.T_S_INTEGRITY,
vtb.T_CER_NUMBER,
vtb.T_RES_NUMBER,
vtb.T_INTEGRITY,
vtb.AUDIT_STATE,
vtb.SOURCE_IMAGE_URL,
vu.ID,
vu.university_name,
wm_concat(distinct vs.SUBJECT_NAME) as SUBJECT_NAME
from
VATUU_TEACHER_BASIC vtb
LEFT JOIN VATUU_UNIVERSITY vu ON vu.ID = vtb.UNIVERSITY_ID
LEFT JOIN VATUU_TEACHER_RESEARCH vtr ON vtr.TEACHERBASIC_ID = vtb.ID
LEFT JOIN VATUU_SUBJECT vs ON vs.ID = vtr.SUBJECT_ID
where ROWNUM <= 12 and ROWNUM >=1
group by
vtb.ID,
vtb.USER_ID,
vtb.T_USER_NAME,
vtb.T_EMAIL,
vtb.USER_ID_CARD,
vtb.UNIVERSITY_ID,
vtb.UNIVERSITY_ACADEMY,
vtb.UNIVERSITY_TITLE,
vtb.MASTER_MENTOR,
vtb.DOCTOR_MENTOR,
vtb.T_POSITION,
vtb.TEACHINGAGE,
vtb.TOP_EDUCATION,
vtb.T_GENDER,
vtb.T_BIRTHDAY,
vtb.T_MOBILEPHONE,
vtb.AREA_ID,
vtb.BIG_IMAGE_URL,
vtb.SMALL_IMAGE_URL,
vtb.PERSONAL_HOME_URL,
vtb.MAILING_ADDRESS,
vtb.OFFICE_ADDRESS,
vtb.MSG_FROM,
vtb.ADDTIME,
vtb.DELETESTATUS,
vtb.T_QQ,
vtb.ADMIN_ID,
vtb.T_E_NAME,
vtb.T_E_SURNAME,
vtb.T_B_INTEGRITY,
vtb.T_S_INTEGRITY,
vtb.T_CER_NUMBER,
vtb.T_RES_NUMBER,
vtb.T_INTEGRITY,
vtb.AUDIT_STATE,
vtb.SOURCE_IMAGE_URL,
vu.ID,
vu.university_name
order by vtb.addTime desc
这是我写的一个sql语句，我是想做个多表的查询，现在数据能查出来，但是有重复的，我去重合并以后，出现了一个问题，就是 where ROWNUM <= 12 and ROWNUM >=1 这里我想查询的是12条数据，但是因为和合并和去重，所以数据并不是12条，应该怎么改才能让我查询自己想要的数据条数。
