select seq_no from 表1 WHERE SE_NO ='202'
select UPD_ID from 表2 where table_no='1' and type='1' and seq_no ='"& seq_no &"'
select USERNAME from 表3 where USER_ID ='"& UPD_ID &"'
select UPD_ID from 表2 where table_no='1' and type='1' and seq_no ='"& seq_no &"'
select USERNAME from 表3 where USER_ID ='"& UPD_ID &"'
t1.seq_no,
t2.UPD_ID,
t3.USERNAME
from 表1 t1,表2 t2,表3 t3
WHERE t1.SE_NO ='202'
and t2.table_no='1' and t2.type='1' and t2.seq_no =t1.seq_no
and t3.USER_ID =t2.USER_ID
select USER_NAME
from 表3
where USER_ID = (select UPD_WHO from 表2 where no='1' and type='1'
and seq_no = (select seq_no from 表1 WHERE SE_NO ='202') )
select UPD_ID from 表2 where table_no='1' and type='1' and seq_no in (
select seq_no from 表1 WHERE SE_NO ='202'
)
)
from 表2 a, 表3 b, 表1 c
where 1 = 1
and a.UPD_ID = b.USER_ID
and a.seq_no = c.seq_no
and a.table_no = '1'
and a.type = '1'
and c.SE_NO = '202'
--a.UPD_ID , b.USER_ID, a.seq_no , c.seq_no 这几个地段注意加索引