SQL query statement for addition and subtraction of mysql date

The job needs to query the data of this month and this month for ranking. Take a closer look at the date format saved in the database as 2010-02-2314: 2: 3, in this way, I thought that the query method of the database by second would not work. I found a date addition and subtraction SQL function datediff (now, oldtime) on the Internet ). After testing, you can use the following:

The job needs to query the data of this month and this month for ranking. Take a closer look at the date format stored in the database, which is, in this way, I thought that the query method of the database by second would not work. I found a date addition and subtraction SQL function datediff (now, oldtime) on the Internet ). After testing, you can use the following: