create table b(c timestamp);这条语句为什么会报无效数据类型的错误,oracle中的时间戳数据类型应该如何定义？谢谢！

瞧瞧，Oracle数据字典中对TIMESTAMP的定义
SQL> desc user_objects;
 名称                                      空?      类型
 ----------------------------------------- -------- --------------
 OBJECT_NAME                                        VARCHAR2(128)
 SUBOBJECT_NAME                                     VARCHAR2(30)
 OBJECT_ID                                          NUMBER
 DATA_OBJECT_ID                                     NUMBER
 OBJECT_TYPE                                        VARCHAR2(18)
 CREATED                                            DATE
 LAST_DDL_TIME                                      DATE
 TIMESTAMP                                          VARCHAR2(19)
 STATUS                                             VARCHAR2(7)
 TEMPORARY                                          VARCHAR2(1)
 GENERATED                                          VARCHAR2(1)
 SECONDARY                                          VARCHAR2(1)