oracle把字符串和nul等同對待l
insert into dy_test (id,name) values ('','dongyuan');
insert into dy_test (id,name) values (null,'dongyuan');
用下面的查詢語句,以上兩條數據都會顯示
select * from dy_test where id is null;oracle把字符串和nul等同對待l
insert into dy_test (id,name) values ('','dongyuan');
insert into dy_test (id,name) values (null,'dongyuan');
用下面的查詢語句,以上兩條數據都會顯示
select * from dy_test where id is null;