MySQL 8.0

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create table t (id int auto_increment primary key, name varchar(255) unique)
insert into t (name) values ('adam')  on duplicate key update id = last_insert_id(id);
select last_insert_id()

last_insert_id()

1

select * from t

id
name

1
adam

insert into t (name) values ('eve') on duplicate key update id = last_insert_id(id);
select last_insert_id()

last_insert_id()

2

insert into t (name) values ('adam') on duplicate key update id = last_insert_id(id);
select last_insert_id()

last_insert_id()

1