oracle数据库插入或者更新判断是否存在记录的SQL

1、插入的时候判断是否存在，若存在则忽略，若不存在则插入

写法①

insert into student(id,name,sex) 
select '111','张三','女' from dual
where not exists (select 1 from student where id= '111')

写法②

insert
when (not exists (select 1 from student where id= '111'))then into student(id,name,sex) values ('111','张三','女')select 1 from dual;

2、更新的时候判断是否存在，若存在则更新，若不存在则插入

写法①

beginupdate student set name = '张三' where id= '111'
if sql%notfound theninsert into student(id,name,sex) values('111','张三','女')
end if;
end;

写法②

begininsert into student(id,name,sex)select '111','张三','女' from dualwhere not exists (select 1 from student where id= '111');
if sql%notfound theninsert into student(id,name,sex) values('111','张三','女');update student set name = '张三' where id= '111';
end if;
end;
commit;