如何在雪花数据仓库中创建循环序列

虽然Snowflake现在不支持它(请考虑在Snowflake社区论坛中提交一个功能请求),但您可以(主要)使用UDF来模拟它,例如:

create or replace sequence seq;
create or replace function cyclic_seq() returns int as 'mod(seq.nextval, 3)';
create or replace table x(s string, i int default cyclic_seq());

insert into x(s) values('a');
insert into x(s) values('b');
insert into x(s) values('c');
insert into x(s) values('d');
insert into x(s) values('e');
insert into x(s) values('f');

select * from x;
---+---+
 S | I |
---+---+
 a | 1 |
 b | 2 |
 c | 0 |
 d | 1 |
 e | 2 |
 f | 0 |
---+---+