?文档中的解释：It returns?TRUE?if an?INSERT,?UPDATE, or?DELETE?statement affected no rows, or a?SELECT?INTO?statement returned no rows. Otherwise, it returns?FALSE.
这个解释更加精妙：
%NOTFOUND?is the logical opposite of?%FOUND.?%NOTFOUND?yields?FALSE?if the?last?fetch returned a row, or?TRUE?if the?last?fetch failed to return a row
错误的例子：
tableA
id? name