已创建 1 行。

SCOTT@orcl> commit;

提交完成。

SCOTT@orcl> select * from long_test where msg='123';
select * from long_test where msg='123'
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? *
第 1 行出现错误:
ORA-00997: 非法使用 LONG 数据类型

SCOTT@orcl> /

? ? ? ? ID MSG
---------- --------------------------------------------------------------------------------
? ? ? ? 1 hello world

SCOTT@orcl> select id, trim(msg) from long_test where id = 1;
select id, trim(msg) from long_test where id = 1
? ? ? ? ? ? ? ? *
第 1 行出现错误:
ORA-00932: 数据类型不一致: 应为 NUMBER, 但却获得 LONG3、CLOB
可以使用CLOB类型大块的字符数据。每一个CLOB变量存储一个定位器，指向一个大块字符数据。

CLOBs participate fully in transactions, are recoverable, and can be replicated. Changes
made by package DBMS_LOB can be committed or rolled back. CLOB locators can span
transactions (for reads only), but they cannot span sessions.

CLOB参与整体事务，可恢复，并且可以重复。
由DBMS_LOB包改变的数据可以提交和回滚。CLOB定位器可以跨事务，但不能跨会话。

4、BLOB
You use the BLOB datatype to store large binary objects in the database, in-line or
out-of-line. Every BLOB variable stores a locator, which points to a large binary object.
BLOBs participate fully in transactions, are recoverable, and can be replicated. Changes
made by package DBMS_LOB can be committed or rolled back. BLOB locators can span
transactions (for reads only), but they cannot span sessions.

用于存储大二进制对象，BLOB参与整体事务，可恢复，并且可以重复。
由DBMS_LOB包改变的数据可以提交和回滚。BLOB定位器可以跨事务，但不能跨会话。

drop table blob_test;

SCOTT@orcl>? create table blob_test(? id number primary key,? content blob not null);

表已创建。

SCOTT@orcl> insert into blob_test values(1,'11111000011111');

已创建 1 行。

SCOTT@orcl> commit;

提交完成。

SCOTT@orcl> select * from blob_test;

SCOTT@orcl> set linesize 2000
SCOTT@orcl> /

? ? ? ? ID CONTENT
---------- -----------------------------------
? ? ? ? 1 11111000011111

SCOTT@orcl> insert into blob_test values(1,'11111000011111>');
insert into blob_test values(1,'11111000011111>')
? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? *
第 1 行出现错误:
ORA-01465: 无效的十六进制数字

?SCOTT@orcl> update blob_test set content=to_blob('110010000110011') where id=1;

已更新 1 行。

SCOTT@orcl> rollback
? 2? ;

回退已完成。

SCOTT@orcl> select * from blob_test;

? ? ? ? ID CONTENT
---------- ---------------------------------------------------------------------
? ? ? ? 1 11111000011111

?delete from blob_test where id=1;
?commit;