谢谢 t-clausen.dk,救了我几天。
要获取每天的实例数:
declare @from datetime= '3/1/2013'
declare @to datetime = '3/31/2013'
select
datediff(day, -7, @to)/7-datediff(day, -6, @from)/7 AS MON,
datediff(day, -6, @to)/7-datediff(day, -5, @from)/7 AS TUE,
datediff(day, -5, @to)/7-datediff(day, -4, @from)/7 AS WED,
datediff(day, -4, @to)/7-datediff(day, -3, @from)/7 AS THU,
datediff(day, -3, @to)/7-datediff(day, -2, @from)/7 AS FRI,
datediff(day, -2, @to)/7-datediff(day, -1, @from)/7 AS SAT,
datediff(day, -1, @to)/7-datediff(day, 0, @from)/7 AS SUN