我有如下表格：

我必须计算每个用户每天会话的平均次数。
首先，我计算了每个用户每天的会话总数，并从中计算出每天会话的平均数。我知道它不会工作，因为所有用户没有会话的每个日期。一些日期是所有用户丢失。当某些日期没有条目时，有没有办法计算日均值

WITH daily_count AS
(
  SELECT user_id,  to_char(local_time,’MM/DD/YYYY’) AS Date, count(session_id) AS  total_count
  FROM table_name
  GROUP BY device_id, to_char(local_time,’MM/DD/YYYY’)
)
SELECT user_id , AVG(total_count) AS average_session_count
FROM daily_count
GROUP BY user_id 

For eg: The max date in the above given table is Feb04 and the min date is Jan31 .So the total no of days is 5 days.If we take Userid 1, it is having records only for 2 dates. So the query i wrote will calculate average for 2 days not for 5 days. How to make it to calculate average for 5 days