I have a table with the date filed entered as INT, so for example 1262817810 as date value.
I’d like to retrieve the rows grouped by day, so I’ll need to convert the INT value of my date to a day value, because now every value is different, as it is counted in seconds.
when you say “retrieve the rows grouped by day” what exactly do you mean?
GROUP BY performs aggregation, i.e. it collapses multiple table rows into one result row, and the result row is not the same as a table row
are you sure you want to do grouping? if so, what aggregate value(s) do you want to return? earlest time in the day? average time in the day? latest time in the day? number of time values in the day?
I’ll try to explain. I have a table with data about revenue. Every column has a customer, a date and revenue (and other fields). The date field is an INT, based on the second the row has been entered. In a report, I’d like to show, per day, the total revenue per customer.
So:
11/11/2011
Customer 1 500€
Customer 2 400€
12/11/2011
Customer 3 600€
Customer 2 300€
…
The problem is that my date filed is detailed to the second,a nd I want to show it per day.
So I thought I needed to group it by DAY(date). But maube I need sth else?
weird, we had just recently a (long, tortured, and semi-hijacked) thread with exactly the same premise…
my advice to you is the same as i gave early in that thread (post #12) –
all you need for your query is a simple SELECT, one that returns the rows you want in timestamp order
SELECT `date`
, other_columns
FROM revenue
ORDER
BY `date`
then, in your php code (if php is what you’re using), look at each returned row and compare it to the previous row, and when the day changes, print the new day as a header before printing that result row
if i did php, i’d mock up the code for you, but i don’t (i do coldfusion instead)
“current/previous” logic is actually fairly common, and as far as detecting a date change, i’m sure php has the appropriate functions
p.s. note that i put date in backticks, because DATE is a reserved word in mysql… you’d be better off renaming that column
Can you have multiple entries for revenue per customer per day?
IE can you have:
Cust1 = 1, date = 1262817810, revenue = 500.45
Cust1 = 1, date = 1262817900 revenue = 201.38
Why are you storing your dates as ints rather than as dates? If you stored them as dates you’d be able to use the built in functions to extract the date in whatever format you want.