grails - grails 中不可预测的 "Could not synchronize database state with session"异常

Question

我开始在日志中看到“无法将数据库状态与 session 同步”异常，并且很难重现它。有时它工作正常......我看到两个异常(它们发生在不同的时间):

ERROR JDBCExceptionReporter - Deadlock found when trying to get lock; try restarting transaction ERROR PatchedDefaultFlushEventListener - Could not synchronize database state with session org.hibernate.exception.LockAcquisitionException: could not update: [com.myapp.School#1911]

还有

ERROR PatchedDefaultFlushEventListener - Could not synchronize database state with session org.hibernate.StaleObjectStateException: Row was updated or deleted by another transaction (or unsaved-value mapping was incorrect): [com.myapp.School#1905]

这是抛出它们的方法:

def populateFriends(ArrayList<FriendView> friends, User user) {

    friends.eachWithIndex { friendView, index ->

        def friend = Friend.findByFriendId(friendView.id) ?: new Friend()
        def schoolName = friendView.schoolName
        def school = null
        if (schoolName) {
            school = School.findByName(schoolName) ?: new School(name: schoolName).save(flush:true)
        }
        if (school) {
            // add to user's school list
            user = User.get(user.id)
            user.addToSchools(school)
            user = user.merge(flush: true)
            user.save(flush: true)

            friend.school = school
        }
        friend.save(flush: true)
    }
}

我一整天都在做这件事，非常感谢任何帮助。

Answer 1

这里的答案是使用lock:true。

School.findByName(name, [lock: true])