刪除和更新不了呢，為什么呢？
刪除的時候前臺顯示這個錯：
type?Exception report
message?attempt to create delete event with null entity
description?The server encountered an internal error that prevented it from fulfilling this request.
后臺提示這個錯：ERROR - Exception occurred during processing request: attempt to create delete event with null entity
java.lang.IllegalArgumentException: attempt to create delete event with null entity
更新的時候提示這個錯：
type?Exception report
message?Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; nested exception is org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
description?The server encountered an internal error that prevented it from fulfilling this request.
exception
org.springframework.orm.hibernate3.HibernateOptimisticLockingFailureException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1; nested exception is org.hibernate.StaleStateException: Batch update returned unexpected row count from update [0]; actual row count: 0; expected: 1
