人员sql语句

select count(nvl2(substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),
substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),a.t_p_xm)) as c, nvl2(substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),
substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),a.t_p_xm) 
as xm from ysu_fams_taskperson a
left join 
ysu_fams_tasks b 
on a.t_id = b.t_id 
where nvl2(substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),
substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),a.t_p_xm) in ('郑','张')
and b.t_startdate > to_date('2010-01-01','yyyy-mm-dd') and 
b.t_startdate < to_date('2010-06-30','yyyy-mm-dd') 
group by nvl2(substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),
substr(a.t_p_xm,0,instr(a.t_p_xm,'[')-1),a.t_p_xm)