不知道informix內有沒有類似mssql的這種SQL語法?
update TABLEa
set a2=b2, a3=b3
from TABLEb
where a1=b1

我現在都是用
update TABLEa
set a2=(select b2 from TABLEb where b1=a1),
a3=(select b3 from TABLEb where b1=a1)

這樣好像是會去TABLEb裡面抓2次資料, 好像效率不太好.

問過informix原廠人員, 無解......可能要等到新版才會有改善吧
目前還是用
update TABLEa
set a2=(select b2 from TABLEb where b1=a1),
a3=(select b3 from TABLEb where b1=a1)

update Table1
set (col1, col2, col3)=((select col10, col20, col30 from Table2 where col10=col1))