How to get the data per month in MySQL - mysql

Question

I'm trying to get the data per every month.
I'm a newbie at MySQL.
I just google and learn from the internet.
So, My Query may be not suitable.
If not suitable, please fix my query.
HERE IS MY QUERY
SELECT
SUM( cr_dt > EXTRACT( YEAR_MONTH FROM CURDATE() )
AND
cr_dt < EXTRACT( YEAR_MONTH FROM CURDATE() + INTERVAL 1 MONTH )
) as thisMonth,
SUM( cr_dt > EXTRACT( YEAR_MONTH FROM CURDATE() - INTERVAL 1 MONTH
AND
cr_dt < EXTRACT( YAER_MONTH FROM CURDATE()
) as last1Month
FROM MYTABLE
I just found the EXTRACT() and INTERVAL, but I don't know it may suitable.
If you have a better way to solve, share please.
WHAT I EXPECT
| thisMonth | last1Month |
+-----------+------------+
| 123 | 1294 |
WHAT I SEE NOW
| thisMonth | last1Month |
+-----------+------------+
| 0 | 0 |
SAMPLE DATAS
| idx | cr_dt |
+-----+---------------------+
| 1 | 2018-02-01 17:00:00 |
| 2 | 2018-02-19 16:00:00 |
| 3 | 2018-02-28 15:00:00 |
| 4 | 2018-03-04 14:00:00 |
| 5 | 2018-04-01 13:00:00 |
| 6 | 2018-04-09 12:00:00 |
| 7 | 2018-04-12 11:00:00 |
| 8 | 2018-04-17 10:00:00 |

Answer 1

You need to use conditional aggregation here, something like this:
SELECT
COUNT(CASE WHEN cr_dt >= DATE_FORMAT(CURRENT_DATE, '%Y/%m/01')
THEN 1 END) AS thisMonth,
COUNT(CASE WHEN cr_dt >= DATE_FORMAT(CURRENT_DATE - INTERVAL 1 MONTH, '%Y/%m/01') AND
cr_dt < DATE_FORMAT(CURRENT_DATE, '%Y/%m/01') THEN 1 END) AS last1Month
FROM MYTABLE
WHERE cr_dt >= DATE_FORMAT(CURRENT_DATE - INTERVAL 1 MONTH, '%Y/%m/01');
More typically you might see this sort of query using a GROUP BY clause, to compute aggregates over individual groups. In your case, however, it appears you want to aggregate over the entire table.