交易系统查询带上for update

SESSION 1：

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      100

SQL> update testmm set amount=amount * 1.1 where id=1;

1 row updated.

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      110

SQL> commit;

Commit complete.

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      110
    
    




SESSION 2：
[oracle@yyjk ~]$ sqlplus tlcbuser/tlcbuser

SQL*Plus: Release 11.2.0.4.0 Production on ?..浜.4?.12 09:41:12 2019

Copyright (c) 1982, 2013, Oracle.  All rights reserved.


Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      100

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      100

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      100

SQL>  update testmm set amount=amount * 1.1 where id=1;

1 row updated.

SQL> select * from testmm;

   ID     AMOUNT
---------- ----------
    1      121