hive之greatest和least函数

1、greatest函数：

greatest(col_a, col_b, ..., col_n)比较n个column的大小，过滤掉null或对null值进行处理，当某个column中是string，而其他是int/double/float等时，返回null；

举例：

select greatest(1, 2, 3, 4) --4
select greatest(-1, 1, 2, 3, null) --null
select greatest(-1, 1, 2, 3, "aaaa") --null
select greatest("2024-08-11","2024-08-12","2024-08-13") --2024-08-13
select greatest("2024-08-11 16:11:11","2024-08-12 17:17:17","2024-08-13 18:18:18") --2024-08-13 18:18:18

2、least函数：
select least(-1, 1, 2, 3) -- -1

select least(-1, 1, 2, 3, null) --null

select least(-1, 1, 2, 3, "aaaa") --null

select least("2024-08-11","2024-08-12","2024-08-13") --2024-08-11

select least("2024-08-11 16:11:11","2024-08-12 17:17:17","2024-08-13 18:18:18") --2024-08-11 16:11:11