SQL Server查询以从另一个字符串月份中获取字符串中的上个月名称

Question

I need to get previous month name from given month name.

For example I need to get previous month as May for the given month June. There is no date.

I tried select CAST(Monthname-1 AS Varchar(max)) from table

Answer 1

Because "There is no date."

You can convert an augmented string {month name} + ' 01, 1980' to a date, and then perform the date calculation

Example

 Select datename(MONTH,dateadd(MONTH,-1,convert(date,'June'+' 01,1980')))

If 2012+ and potentially bogus data ... try_convert()

 Select datename(MONTH,dateadd(MONTH,-1,try_convert(date,'June'+' 01,1980')))

Returns

May

Answer 2

在开始日期前加上-1个月，然后使用DATENAME(month)来获取名称。

DATENAME(month, DATEADD(month, -1, <yourDateField>))

Answer 3

您可以尝试以下方法：

SELECT DATENAME(MM,CAST('1 June 2018' AS datetime)-1)