How do I get the first day of the week of a date in mysql?

Question

Suppose I have 2011-01-03 and I want to get the first of the week, which is sunday, which is 2011-01-02, how do I go about doing that?

The reason is I have this quer

Answer 1

This is a much simpler approach than writing a function to determine the first day of a week.

Some variants would be such as
SELECT DATE_ADD((SELECT CURDATE() - INTERVAL (WEEKDAY(CURDATE())+1)DAY),INTERVAL 7 DAY) (for the ending date of a query, such as between "beginning date" and "ending date").
SELECT CURDATE() - INTERVAL (WEEKDAY(CURDATE())+1) DAY (for the beginning date of a query).

This will return all values for the current week. An example query would be as follows:
SELECT b.foo FROM bar b
WHERE b.datefield BETWEEN
(SELECT CURDATE() - INTERVAL (WEEKDAY(CURDATE())+1) DAY)
AND
(SELECT DATE_ADD((SELECT CURDATE() - INTERVAL (WEEKDAY(CURDATE())+1)DAY),INTERVAL 7 DAY))

Answer 2

Week starts day from sunday then get First date of the Week and Last date of week

SELECT  
  DATE("2019-03-31" + INTERVAL (1 - DAYOFWEEK("2019-03-31")) DAY) as start_date,  
  DATE("2019-03-31" + INTERVAL (7 - DAYOFWEEK("2019-03-31")) DAY) as end_date

Week starts day from Monday then get First date of the Week and Last date of week

SELECT  
  DATE("2019-03-31" + INTERVAL ( - WEEKDAY("2019-03-31")) DAY) as start_date, 
  DATE("2019-03-31" + INTERVAL (6 - WEEKDAY("2019-03-31")) DAY) as end_date

Answer 3

If the week starts on Sunday do this:

DATE_ADD(mydate, INTERVAL(1-DAYOFWEEK(mydate)) DAY)

If the week starts on Monday do this:

DATE_ADD(mydate, INTERVAL(-WEEKDAY(mydate)) DAY);

more info

Answer 4

This works form me

Just make sure both dates in the below query are the same...

SELECT ('2017-10-07' - INTERVAL WEEKDAY('2017-10-07') Day) As `mondaythisweek`

This query returns: 2017-10-02 which is a monday,

But if your first day is sunday, then just subtract a day from the result of this and wallah!

Answer 5

If week starts on Monday

  SELECT SUBDATE(mydate, weekday(mydate));

If week starts on Sunday

  SELECT SUBDATE(mydate, dayofweek(mydate) - 1);

Example:

SELECT SUBDATE('2018-04-11', weekday('2018-04-11'));

2018-04-09

SELECT SUBDATE('2018-04-11', dayofweek('2018-04-11') - 1);

2018-04-08

Answer 6

select '2011-01-03' - INTERVAL (WEEKDAY('2011-01-03')+1) DAY; 

returns the date of the first day of week. You may look into it.