Çó´Ësql¼ò»¯

SQL code:
select a.nm
from a
where a.op_id=(select a.op_id
from a,b
where a.op_id=b.u_id and b.or_id=(select b.or_id
from b,c
where b.or_id=c.re_id and c.re_id='000022'))

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SQL code:
select select a.nm
from a,b,c
where a.op_id=b.u_id
and b.or_id=c.re_id
and c.re_id='000022'

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ͬÒâLS

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SQL code:
select a.nm
from a,b
where a.op_id=b.u_id and b.or_id='000022'

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SQL code:

select a.nm from a,b,c
where a.op_id=b.u_id and b.or_id=c.re_id and c.re_id='000022'

--or
select a.nm from a,b
where a.op_id=b.u_id and b.or_id='000022'

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ÒýÓÃ

select select a.nm
from a,b,c
where a.op_id=b.u_id
and  b.or_id=c.re_id
and  c.re_id='000022'

dui

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select a.nm,b.nm from a,b
where a.ap_id=b.u_id and a.op_id=b.u_id and  b.o