如何按月计算列中的值？

Question

In my data frame, I am trying to count number of values of a column per month, given by the time column in SQL. I want the output to have a count of the number of values in a column for each month. I know I can use the where function to count for one month and I could do this for all 12 months, but was wondering if there was a more efficient way. Here's the inefficient example:

SELECT
    count(column1) AS Total
FROM DataFrame
WHERE MONTH(date) == 1
 GROUP by column1 ORDER by count(column1) DESC LIMIT 10

Answer 1

I am trying to count distinct values of a column per month, given by the time column in SQL. I

You seem to want GROUP BY :

SELECT MONTH(date) as mon, approx_count_distinct(column1, 0.1) AS Total
FROM DataFrame
GROUP by MONTH(date)
ORDER by Total DESC
LIMIT 10;

Note that using MONTH() without YEAR() or a filter on the date is highly suspicious.