mysql - 在 sqlite 中如何完成“如果某列存在则 select，否则 insert”这样的原子操作？

Question

只知道 replace into 的功能，不知道怎样 select。

Answer 1

INSERT OR REPLACE INTO TABLE name (f1, f2, f3) VALUES (v1, v2, v3)

Well, I read the wrong question. I thought it was insert or update, but it turned out to be select or insert.

Besides enabling transaction, I didn’t think of any good way to select or insert, but there is a solution to select with default value

select id, f1, f2 from sometable where id=3 union
select 999 as id, 'default_value1' as f1, 'default_value2' as f2
where not exists (select 1 from sometable where id=3)

999 is the default value of id