org.hibernate.TransientObjectException: object references an unsaved transient instance

 

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