Question

我希望循环使用这些年，并使用下面的while循环获取每年每个月的计数。如何通过限制年数来实现这一目标。

declare @start_year int=1999
declare @loop_year int
declare @end_year int=2015

WHILE (@end_year <2015)
BEGIN

Select    count(*) as rows,month(create_datetime) as month, year(create_datetime) as year
FROM      [table_name]
WHERE     year(create_datetime) =@loop_year
GROUP BY  month(create_datetime),year(create_datetime)
set @loop_year=@start_year+1
END

Answer 1

我认为你的WHILE循环搞砸了。您宣布@end_year = 2015然后说WHILE (@end_year < 2015)。我认为你的意思是WHILE (@loop_year < @end_year)。

话虽如此，没有理由对这种特殊情况使用循环。这应该可以实现相同的结果：

Select count(*) as rows,
    month(create_datetime) as month, 
    year(create_datetime) as year
FROM      [table_name]
WHERE     year(create_datetime) BETWEEN 1999 AND 2014
GROUP BY  month(create_datetime), year(create_datetime)

while循环在t-sql中有开始和结束年份

1 个答案: