摘要: 1.先看看Null与''在oracle中的表现 SQL> select * from test_null where nvl(name_,'')=''; no rows selected SQL> select * from test_null where nvl(name_,'A')='A'; I 阅读全文
posted @ 2017-03-31 11:39 Alex-Zeng 阅读(775) 评论(0) 推荐(0) 编辑