query optimization - MySQL compare data from date ranges prior to the current row and count() them -

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this in reference still-open question here - want try approach differently.

i have mysql table 2 pieces of information: order_date , email_address. exhaustive , non-distinct, meaning there duplicates if happened make more 1 purchase per-day.

i need following report in few queries possible, one:

yyyy-mm | number_emails_this_month | numer_emails_repeated_prior

where sample output query result this:

yyyy-mm | number_emails_this_month | numer_emails_repeated_prior 2010-02     23423               1231 2010-03     4422                2234 2010-04     1424                650

any appreciated!

i not sure understand number_emails_repeated_prior. if post short example of data , corresponding example of wanted results helpful.

taking guess aiming for, number of emails specific user per month need is:

select date_format(order_date, '%y-%m') `yyyy-mm`,         count(email_address) `number_emails_this_month ` table_name email_address = 'some@address' group 1 order 1

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