hibernate常见异常

异常1：not-null property references a null or transient value
解决方法：将“一对多”关系中的“一”方，not-null设置为false

异常2：org.hibernate.TransientObjectException: object references an unsaved transient instance
解决方法：cascade="save-update,persist"


异常3：org.hibernate.QueryException: could not resolve property
解决方法："from Category category where category.userID = :userID"修改为"from Category category where userID = :userID"或者"from Category category where category.user.id = :userID"


异常4：could not initialize proxy - the owning Session was closed
解决方法：设置lazy为false