Question

How can i replace one row with 5 rows with same data in mysql.for example i have this table

 id   |   companyId   |      name       |  open  |  close
 1    |    1          |    mon-fri      |  10:00 |  19:00  
 2    |    1          |      sat        |  10:00 |  12:00 
 3    |    1          |      sun        |  10:00 |  12:00 
 4    |    2          |    mon-fri      |  10:00 |  16:00  
 5    |    2          |      sat        |  10:00 |  13:00 
 6    |    2          |      sun        |  10:00 |  13:00 

I want to convert name field where its mon-fri to mon , tues , wed , thur , fri .

 id   |   companyId   |      name       |  open  |  close
 1    |    1          |    mon     |  10:00 |  19:00  
 2    |    1          |    tues    |  10:00 |  19:00 
 3    |    1          |    wed     |  10:00 |  19:00 
 4    |    1          |    thur    |  10:00 |  19:00   
 5    |    1          |    fri     |  10:00 |  19:00  
 6    |    1          |    sat     |  10:00 |  12:00 
 7    |    1          |    sun     |  10:00 |  12:00 
.
.
.

Answer 1

You can’t do this via an UPDATE, but what you can do is a series of INSERT INTO ... SELECT making use of some string literals, followed by a DELETE to remove the rows you expanded out.

/* First insert a row for each mon,tue,wed,thur,fri */
/* Column values are copied from the existing mon-fri row, and use the literal strings 'mon', 'tue', etc as the new `name` */
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT `companyId`, 'mon', `open`, `close` FROM yourtable WHERE `name` = 'mon-fri'
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT `companyId`, 'tue', `open`, `close` FROM yourtable WHERE `name` = 'mon-fri'
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT `companyId`, 'wed', `open`, `close` FROM yourtable WHERE `name` = 'mon-fri'
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT `companyId`, 'thur', `open`, `close` FROM yourtable WHERE `name` = 'mon-fri'
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT `companyId`, 'fri', `open`, `close` FROM yourtable WHERE `name` = 'mon-fri'

/* Then delete the original mon-fri rows which you just expanded out */
DELETE FROM yourtable WHERE `name` = 'mon-fri'

http://sqlfiddle.com/#!2/cae33/1

(Credit where due: this excellent suggestion was the work of Andriy M in an unsolicited edit)

You could also reduce the number of statements, as well as the number of table scans, by using a virtual table, like this:

/* Cross-join the existing 'mon-fri' rows with a virtual table of day names
   of 'mon' through 'fri' and insert the resulting set back into your table */
INSERT INTO yourtable (`companyId`, `name`, `open`, `close`)
  SELECT t.`companyId`, v.`name`, t.`open`, t.`close`
  FROM yourtable t
  CROSS JOIN (
    SELECT 'mon' AS `name` UNION ALL
    SELECT 'tue' UNION ALL
    SELECT 'wed' UNION ALL
    SELECT 'thur' UNION ALL
    SELECT 'fri'
  ) v
  WHERE t.`name` = 'mon-fri';

/* Then delete the original mon-fri rows which you just expanded out */
DELETE FROM yourtable WHERE `name` = 'mon-fri';

http://sqlfiddle.com/#!2/98e35/1

Update after comments:

There is no real value to forcing their order when you insert the rows, that is best done in SELECT.

To order by day for each companyId, it will require some work no matter which way it is done. You could call LOWER(STR_TO_DATE()) with %a and compare the weekday value, however you would also need to change your thur to thu since that is how MySQL abbreviates it. That results in a bunch of function calls.

Instead, you can use a CASE.... in the ORDER BY to assign ordinal values to each day, like:

ORDER BY
 companyId,
 CASE `name`
   WHEN 'sun' THEN 1 
   WHEN 'mon' THEN 2
   WHEN 'tue' THEN 3
   WHEN 'wed' THEN 4
   WHEN 'thur' THEN 5
   WHEN 'fri' THEN 6
   WHEN 'sat' THEN 7
 ELSE 8 END

Neither of the above methods is going to be friendly to indexing though.

If you need this to be more performant, I would recommend against storing the strings 'mon','tue','wed',etc in the first place, and instead storing their associated weekday value. See DAYOFWEEK() for details.