两张表SQL关联查询

sql = "select distinct l_dingdan.upic,l_dingdan.pj,l_dingdan.pjnr,l_dingdan.pjdate,l_dingdan.uname from l_dingdan,l_dingdanss where l_dingdanss.ddid=l_dingdan.ddid and l_dingdan.pj>0 and l_dingdan.acting='"+actid+"' and l_dingdanss.proid=" + pid;