[精彩] 如何用sql把一个字段从long raw类型改为blob类型？？？

请教各位 数据库的高手。一个字段原来是long raw类型的，现在要把它改成blob类型，但是原来的纪录都要保留。不知道这两种类型用sql文怎么转换。
请执教！！！[color=red][/color]
chaoping 回复于：2003-02-22 19:23:43
看看这个例子：
SQL>; select count(*) from sys.IDL_UB1$;
COUNT(*)
----------
4003
SQL>; desc sys.IDL_UB1$
Name                                                                                                              Null?    Type
----------------------------------------------------------------------------------------------------------------- -------- ----------------------------------------------------------------------------
OBJ#                                                                                                              NOT NULL NUMBER
PART                                                                                                              NOT NULL NUMBER
VERSION                                                                                                                    NUMBER
PIECE#                                                                                                            NOT NULL NUMBER
LENGTH                                                                                                            NOT NULL NUMBER
PIECE                                                                                                             NOT NULL LONG RAW
SQL>; create table system.rawtolob(obj,part,version,piece#,length,piece)
2  as
3  select obj#,part,version,piece#,length,to_lob(piece) from sys.idl_ub1$;
Table created.
SQL>; select count(*) from rawtolob;
COUNT(*)
----------
4003
SQL>; desc rawtolob
Name                                                                                                              Null?    Type
----------------------------------------------------------------------------------------------------------------- -------- ----------------------------------------------------------------------------
OBJ                                                                                                               NOT NULL NUMBER
PART                                                                                                              NOT NULL NUMBER
VERSION                                                                                                                    NUMBER
PIECE#                                                                                                            NOT NULL NUMBER
LENGTH                                                                                                            NOT NULL NUMBER
PIECE                                                                                                                      BLOB