MSSQL 获取指定日期所在星期的第一天和最后一天日期 获取指定日期坐在月的第一天和最后一天

ufn_GetWeekFirstAndEndDay    获取指定日期所在星期的第一天和最后一天日期

ALTER FUNCTION [dbo].[ufn_GetWeekFirstAndEndDay](@tmpDate DATETIME)
RETURNS  @tmpTable TABLE(        
    FirstDay DATETIME ,      
    EndDay DATETIME   
)
AS
BEGIN
    INSERT INTO @tmpTable
    SELECT a.FirstDay,b.EndDay FROM (    
        SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 0) AS FirstDAy
    ) a
    LEFT JOIN (
        SELECT 1 AS ID,DATEADD(wk, DATEDIFF(wk,0,@tmpDate), 6) AS EndDay
    ) b
    ON a.ID = b.ID
    RETURN
END
ufn_GetMonthFirstAndEndDay    获取指定日期坐在月的第一天和最后一天
ALTER FUNCTION [dbo].[ufn_GetMonthFirstAndEndDay](@tmpDate DATETIME)
RETURNS  @tmpTable TABLE(        
    FirstDay DATETIME ,      
    EndDay DATETIME   
)
AS
BEGIN
    INSERT INTO @tmpTable
    SELECT a.FirstDay,b.EndDay FROM (    
        SELECT 1 AS ID, CONVERT(varchar(10),DATEADD(DAY,-DATEPART(DAY,GETDATE())+1,GETDATE()),23)  +' 00:00:00' AS 'FirstDay'
    ) a
    LEFT JOIN (
        SELECT 1 AS ID, CONVERT(varchar(10),DATEADD(DAY,-1,DATEADD(MONTH,1,GETDATE()-DAY(GETDATE())+1)),23)+' 23:59:59' AS 'EndDay'
    ) b
    ON a.ID = b.ID
    RETURN
END