大于等于28SQL Server中超过28天的月份统计（sqlserver月几天）

There are occasions when one may want to calculate months with more than 28 days in SQL Server. The challenge that may arise is that a generic T-SQL function does not exist for this computation. Nonetheless, the ability to perform such computation is made possible through the proper use of date functions in T-SQL, combined with the ability to leverage cursors or a looping construct within a stored procedure.

In this post, we shall be focusing on how to count the number of months in SQL Server with a duration of more than 28 days. We shall start by creating a cursor to loop through each year and month, and then use a combination of several date functions to achieve the desired outcome.

首先，我们创建一个游标来循环每一年和每一个月：

— Declare Cursor declare c1 cursor for select distinct year(date) as [year], month(date) as [month] from tablename order by [year], [month]

接下来，我们使用dateadd函数来计算每个月的总天数：

declare @days int, @month date set @month = dateadd(mm, 1, datefromparts(@year, @month, 1)) set @days = datediff(dd, datefromparts(@year, @month, 1), @month)

随后，我们通过比较总天数是否大于28来判断每个月是否包含天数大于28天：

if @days > 28 begin — Increment the count set @longmonthcount = @longmonthcount + 1 end

最后，我们返回结果：

— Return result select @longmonthcount count

因此，以上代码是如何用游标和dateadd函数统计超过28天的月份。这种方法可以确保实现这种统计。