update bpm_biz b set dealer_memo = (select e.ASSIGN_MEMO from BPM_TASK t ,BPM_TASK_EXT e where t.TASK_ID = e.TASK_ID and b.INST_ID = t.INST_D and rownum=1 and t.PRE_TASKNAME = 'XXXXX' and t.TASK_NAME = 'XXXXX' order by t.ASSIGN_TIME desc )where exists (select 1 from BPM_TASK t ,BPM_TASK_EXT e where t.TASK_ID = e.TASK_ID and b.INST_ID = t.INST_D and rownum=1 and t.PRE_TASKNAME = 'XXXXX' and t.TASK_NAME = 'XXXXX' order by t.ASSIGN_TIME desc )
原因：这种语句测试时会报“缺少右括号”
解决方案：order by 尽量用 group by 代替，尽管性能慢一些
posted on
