MySQL在没有计算周末的情况下提前两天

Question

is there any way to calculate 2 days ago in MySQL without counting Saturday and Sunday? My data sample:

Wednesday, 20 Sept 2017
Thursday, 21 Sept 2017
Friday, 22 Sept 2017
Saturday, 23 Sept 2017
Sunday, 24 Sept 2017
Monday, 25 Sept 2017
Tuesday, 26 Sept 2017
Wednesday, 27 Sept 2017

When I run query on Friday, 22 Sept 2017 , I will get the first data ( Wednesday, 20 Sept 2017 )

When I run query on Saturday, 23 Sept 2017 , I will get the second data ( Thursday, 21 Sept 2017 )

When I run query on Sunday, 24 Sept 2017, I will get the third data ( Friday, 22 Sept 2017 )

But when I run query on Monday, I won't get any data

And when I run query on Tuesday, I will get the fourth data ( Saturday, 23 Sept 2017 )

And when I run query on Wednesday, I will get both of fifth data and sixth data ( Sunday, 24 Sept 2017 && Monday, 25 Sept 2017 )

My query so far:

SELECT * FROM oc_order WHERE (status_id = '2' AND date_added LIKE CONCAT(DATE_ADD(DATE(NOW()), INTERVAL -2 DAY),'%')) OR (status_id = '21' AND date_modified LIKE CONCAT(DATE_ADD(DATE(NOW()), INTERVAL -2 DAY),'%'))

It works to count 2 days before, but it still count Saturday and Sunday. Basically, I create a query that runs everyday to auto change status a data that have been 2 days with a status. For example, in Wednesday, I will change any data in Monday that have status_id 2 (for example). In the other words, Saturday data will be processed on Tuesday. Sunday data will be processed on Wednesday, including Monday data, it will be processed on Wednesday too

Answer 1

SELECT * FROM   (SELECT status_id,
    date_added,
    date_modified,
    CASE
      WHEN DAYOFWEEK(now()) = 2
      THEN CONCAT(DATE_ADD(DATE(NOW()), INTERVAL -3 DAY),'%')
      WHEN DAYOFWEEK(now()) = 3
      THEN CONCAT(DATE_ADD(DATE(NOW()), INTERVAL -4 DAY),'%')
      ELSE CONCAT(DATE_ADD(DATE(NOW()), INTERVAL -2 DAY),'%')
    END DAY_OF_WEEK   FROM oc_order   ) WHERE (status_id = '2' AND date_added LIKE DAY_OF_WEEK) OR (status_id = '21' AND date_modified LIKE DAY_OF_WEEK)

Answer 2

Finally what I do is set the cron job between monday to friday, so saturday and sunday will not count. Also, these job is better to do in PHP not in SQL. Thanks for any comments and answer