I have 3 tables:
users movements unique_ids
I want to get the records gotten from march until now of the users registered in march, counting the unique id of their movements with a distinct and the total of it at the end:
SELECT MONTH(mo.ctime) AS month, COUNT(DISTINCT(unique_id)) FROM users us, movements mo,unique_ids id WHERE us.time_field > '2014-03-01' AND us.time_field < '2014-03-31 23:59:59' AND mo.time_field > '2014-03-01' AND us.room_name LIKE 'name' AND us.room_name=mo.room_name AND us.user=mo.user AND id.id_log=mo.id_log GROUP BY month WITH ROLLUP
The thing is that few month ago in other query I realise that adding DATE() to the time_field into WHERE clause makes faster the query, but adding this into the query shown, gives me different results than the initial one.
What's the difference between time_field > 'x' AND DATE(time_field) > 'x' inside WHERE clause?