在oracle表中插入空字段和null测试

create table testTable
(
id number,
name varchar2(100)
)
select * from testTable
insert into testTable(id,name) values(1,'user1')
insert into testTable(id,name) values(2,'')
insert into testTable(id,name) values(3,null)

select count(id)  from testTable t where t.name=''

select count(id)  from testTable t where t.name is null or t.name!=''

select id,nvl(name,'null') from testTable

select  id,nullif(name,'') from testTable

drop table testTable