Mysql - count if not in the same day

Question

I must extract a report from MySQL of how many times a client visited our office. The rule is to count a visit only if it has passed 24 from the last visitation.

If a client visits the office two times in one day, this should count as 1 (for the report).

However, the visit will be registered everytime in the database and I cannot change the database or create new tables. I must work with what I have.

Follows a SQL Fiddle of my scenario:

The outuput should be two visits were done in 29/aug, one visit done in 03/sept.

http://sqlfiddle.com/#!2/fc7f5/2/0

Could someone please put me in the right direction to archive this? I googled as much as I could and did not find the right answer.

Thank you very much in advance for your time and help.

Answer 1

Looks like you need to use GROUP BY :

select date(visit_date), count(*) 
from visits 
where client_id =1 
group by date(visit_date)

• SQL Fiddle Demo

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Notes:

• You may or may not need to convert visit_date to a date in the group by -- depends on whether it stores the time of the visit or just the date.
• Also, you may need to use count distinct(client_id) since you mention not counting the same client twice in the same day. A little unclear from your question.

Answer 2

If you use select visit_date,count(*) from visits where client_id=1 group by visit_date You'll see that it now reports 2 visits for 29/aug and one for 03/sept.

Count the number of rows returned to find out how many visits the patient has had.