php - 如果某行不存在，如何更新或返回 FALSE？

Question

如何在一次查询中完成？

Answer 1

你可以这样做:

function updateValue()
{
     mysql_query($sql); // your update goes here
     return mysql_affected_rows() > 0;
}

来自 BoltClock 的评论:

Bear in mind that mysql_affected_rows() returns 0 if a row exists but the old and new values are equal (meaning there was no need for an update).