摘要：
users表有 ，UserPoint表没有1，SELECT COUNT(1) FROM users(nolock) left join UserPoint(nolock) on users.UserID=UserPoint.UserID where Userpoint.UserID IS NULL2，SELECT COUNT(UserID) FROM users WHERE userid NOT In (SELECT userid FROM UserPoint)性能问题3，SELECT COUNT(UserID) FROM users u WHERE Not EXISTS (SELECT U. 阅读全文
