多此一举
既然此语句是唯一,又何必多加后作判断呢
(select a.tx_txzh
from aktxdam a,txdam b
where a.dw_mm = b.dw_mm
and a.tx_grxh = b.tx_grxh )
这样就可以了
update txdam a
set tx_txzh= (select tx_txzh from aktxdam
where dw_mm = a.dw_mm and tx_grxh = a.tx_grxh )
既然此语句是唯一,又何必多加后作判断呢
(select a.tx_txzh
from aktxdam a,txdam b
where a.dw_mm = b.dw_mm
and a.tx_grxh = b.tx_grxh )
这样就可以了
update txdam a
set tx_txzh= (select tx_txzh from aktxdam
where dw_mm = a.dw_mm and tx_grxh = a.tx_grxh )
解决方案 »
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