create table t1 (a bigint unsigned auto_increment primary key);

insert into t1 values((1<<63)-2);

insert into t1 values(NULL); select last_insert_id();

insert into t1 values(NULL); select last_insert_id();

select * from t1;

MariaDB [test]> insert into t1 values(NULL); select last_insert_id();

+---------------------+

| last_insert_id()    |

+---------------------+

| 9223372036854775807 |

+---------------------+

MariaDB [test]> insert into t1 values(NULL); select last_insert_id();

+----------------------+

| last_insert_id()     |

+----------------------+

| -9223372036854775808 |

+----------------------+

MariaDB [test]> select * from t1;

+---------------------+

| a                   |

+---------------------+

| 9223372036854775806 |

| 9223372036854775807 |

| 9223372036854775808 |

+---------------------+