在SQL中插入重复值

Question

试图找到一种简单的方法在表的两列中插入一些重复值，类似于R的rep函数-

例如，我需要插入两个值（巧克力和香草，每次4次），并且需要插入4种重复两次的值，例如-

flavor_type schedule_type
chocolate   weekly
chocolate   monthly
chocolate   quarterly
chocolate   yearly
vanilla     weekly
vanilla     monthly
vanilla     quarterly
vanilla     yearly

Answer 1

您可以使用cross join ：

select *
from (values('chocolate'), ('vanilla')) flavor(flavor_type)
cross join (values('weekly'), ('monthly'), ('quarterly'), ('yearly')) schedule(schedule_type)

输出：

flavor_type schedule_type
----------- -------------
chocolate   weekly
chocolate   monthly
chocolate   quarterly
chocolate   yearly
vanilla     weekly
vanilla     monthly
vanilla     quarterly
vanilla     yearly