How to get first day of every corresponding month in mysql?

Question

I want to get first day of every corresponding month of current year. For example, if user selects \'2010-06-15\', query demands to run from \'2010-06-01\' instead of \'2010

Answer 1

You can use DATE_FORMAT() function in order to get the first day of any date field.

SELECT DATE_FORMAT(CURDATE(),'%Y-%m-01') as FIRST_DAY_CURRENT_MONTH 
FROM dual;

Change Curdate() with any other Date field like:

SELECT DATE_FORMAT(purchase_date,'%Y-%m-01') AS FIRST_DAY_SALES_MONTH 
FROM Company.Sales;

Then, using your own question:

SELECT *
FROM
  hrm_attendanceregister
WHERE
hrm_attendanceregister.Date) >=
 DATE_FORMAT(CURDATE(),'%Y-%m-01')

You can change CURDATE() with any other given date.

Answer 2

I'm surprised no one has proposed something akin to this (I do not know how performant it is):

CONCAT_WS('-', YEAR(CURDATE()), MONTH(CURDATE()), '1')

Additional date operations could be performed to remove formatting, if necessary

Answer 3

date_add(subdate(curdate(), interval day(?) day), interval 1 day)

change the ? for the corresponding date

Answer 4

Is this what you are looking for:

select CAST(DATE_FORMAT(NOW() ,'%Y-%m-01') as DATE);

Answer 5

select big.* from
(select @date := '2010-06-15')var
straight_join 
(select * from your_table where date_column >= concat(year(@date),'-',month(@date),'-01'))big;

This will not create a full table scan.

Answer 6

There is actually a straightforward solution since the first day of the month is simply today - (day_of_month_in_today - 1):

select now() - interval (day(now())-1) day

Contrast that with the other methods which are extremely roundabout and indirect.

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Also, since we are not interested in the time component, curdate() is a better (and faster) function than now(). We can also take advantage of subdate()'s 2-arity overload since that is more performant than using interval. So a better solution is:

select subdate(curdate(), (day(curdate())-1))