MySQLIntegrityConstraintViolationException: Duplicate entry

严重: Servlet.service() for servlet [springmvc] in context with path [] threw exception [Request processing failed; nested exception is org.springframework.dao.DuplicateKeyException: ### Error updating database. Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype' ### The error may involve com.lk.dao.UpDao.add-Inline ### The error occurred while setting parameters ### SQL: insert into lk_up(CU_ID,usercode,pwd,lock_status,T_ID,OG_ID,user_TYPE) values(?,?,?,?,?,?,?) ### Cause: com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype' ; SQL []; Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype'; nested exception is com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype'] with root cause com.mysql.jdbc.exceptions.jdbc4.MySQLIntegrityConstraintViolationException: Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype' 插入数据报错，原因是 Duplicate entry 'admin-2' for key 'idx_unq_usercode_usertype' ，其中idx_unq_usercode_usertype是表的索引，且类型为unique索引，所以当为建立了索引的列赋相同的值进引发该错误。