SQL> desc test1;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 ID                                                 NUMBER
 C1                                                 CLOB

SQL> desc test2;
 Name                                      Null?    Type
 ----------------------------------------- -------- ----------------------------
 ID                                                 NUMBER
 C2                                                 CLOB

SQL> select * from test1;

        ID C1
---------- ------------------------------
         1 test
         2 aaa
         3 934
         4 444

SQL> select * from test2;

        ID C2
---------- ------------------------------
         1 test
         2 abc
         3 3222
         4 444

SQL> set serveroutput on
SQL> declare
  2  cursor cursor1 is select * from test1;
  3  cursor cursor2 is select * from test2;
  4  c1 test1%rowtype;
  5  c2 test2%rowtype;
  6  n number;
  7  begin
  8  open cursor1;
  9  open cursor2;
 10  fetch cursor1 into c1;
 11  fetch cursor2 into c2;
 12  while cursor1%found loop
 13  n:=dbms_lob.compare(c1.c1,c2.c2);
 14  dbms_output.put_line(n);
 15  fetch cursor1 into c1;
 16  fetch cursor2 into c2;
 17  end loop;
 18  end;
 19  /
0
-1
1
0

PL/SQL procedure successfully completed.

返回的是0,clob的内容就是相同的。