oracle把字符串和nul等同对待l
insert into dy_test (id,name) values ('','dongyuan');
insert into dy_test (id,name) values (null,'dongyuan');
用下面的查询语句,以上两条数据都会显示
select * from dy_test where id is null;oracle把字符串和nul等同对待l
insert into dy_test (id,name) values ('','dongyuan');
insert into dy_test (id,name) values (null,'dongyuan');
用下面的查询语句,以上两条数据都会显示
select * from dy_test where id is null;