generate days from date range

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I would like to run a query like

select ... as days where `date` is between '2010-01-20' and '2010-01-24'

And return data like:

days
----------
2010-01-20
2010-01-21
2010-01-22
2010-01-23
2010-01-24
30 Answers

This solution uses no loops, procedures, or temp tables. The subquery generates dates for the last 10,000 days, and could be extended to go as far back or forward as you wish.

select a.Date 
from (
    select curdate() - INTERVAL (a.a + (10 * b.a) + (100 * c.a) + (1000 * d.a) ) DAY as Date
    from (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as a
    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as b
    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as c
    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as d
) a
where a.Date between '2010-01-20' and '2010-01-24' 

Output:

Date
----------
2010-01-24
2010-01-23
2010-01-22
2010-01-21
2010-01-20

Notes on Performance

Testing it out here, the performance is surprisingly good: the above query takes 0.0009 sec.

If we extend the subquery to generate approx. 100,000 numbers (and thus about 274 years worth of dates), it runs in 0.0458 sec.

Incidentally, this is a very portable technique that works with most databases with minor adjustments.

SQL Fiddle example returning 1,000 days

The old school solution for doing this without a loop/cursor is to create a NUMBERS table, which has a single Integer column with values starting at 1.

CREATE TABLE  `example`.`numbers` (
  `id` int(10) unsigned NOT NULL auto_increment,
  PRIMARY KEY  (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

You need to populate the table with enough records to cover your needs:

INSERT INTO NUMBERS (id) VALUES (NULL);

Once you have the NUMBERS table, you can use:

SELECT x.start_date + INTERVAL n.id-1 DAY
  FROM NUMBERS n
  JOIN (SELECT STR_TO_DATE('2010-01-20', '%Y-%m-%d') AS start_date 
          FROM DUAL) x
 WHERE x.start_date + INTERVAL n.id-1 DAY <= '2010-01-24'

The absolute low-tech solution would be:

SELECT STR_TO_DATE('2010-01-20', '%Y-%m-%d')
 FROM DUAL
UNION ALL
SELECT STR_TO_DATE('2010-01-21', '%Y-%m-%d')
 FROM DUAL
UNION ALL
SELECT STR_TO_DATE('2010-01-22', '%Y-%m-%d')
 FROM DUAL
UNION ALL
SELECT STR_TO_DATE('2010-01-23', '%Y-%m-%d')
 FROM DUAL
UNION ALL
SELECT STR_TO_DATE('2010-01-24', '%Y-%m-%d')
 FROM DUAL

What would you use it for?


To generate lists of dates or numbers in order to LEFT JOIN on to. You would to this in order to see where there are gaps in the data, because you are LEFT JOINing onto a list of sequencial data - null values will make it obvious where gaps exist.

Elegant solution using new recursive (Common Table Expressions) functionality in MariaDB >= 10.3 and MySQL >= 8.0.

WITH RECURSIVE t as (
    select '2019-01-01' as dt
  UNION
    SELECT DATE_ADD(t.dt, INTERVAL 1 DAY) FROM t WHERE DATE_ADD(t.dt, INTERVAL 1 DAY) <= '2019-04-30'
)
select * FROM t;

The above returns a table of dates between '2019-01-01' and '2019-04-30'. It is also decently fast. Returning 1000 years worth of dates (~365,000 days) takes about 400ms on my machine.

You'd like to get the a date range.

In your example you'd like to get the dates between '2010-01-20' and '2010-01-24'

possible solution:

 select date_add('2010-01-20', interval row day) from
 ( 
    SELECT @row := @row + 1 as row FROM 
    (select 0 union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t,
    (select 0 union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t2, 
    (select 0 union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t3, 
    (select 0 union all select 1 union all select 2 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t4, 
    (SELECT @row:=-1) r
 ) sequence
 where date_add('2010-01-20', interval row day) <= '2010-01-24'

Explanation

MySQL has a date_add function so

select date_add('2010-01-20', interval 1 day)

will give you

2010-01-21

The datediff function would let you know often you'd have to repeat this

select datediff('2010-01-24', '2010-01-20')

which returns

 4

Getting a list of dates in a date range boils down to creating a sequence of integer numbers see generate an integer sequence in MySQL

The most upvoted answer here has taken a similar approach as https://stackoverflow.com/a/2652051/1497139 as a basis:

SELECT @row := @row + 1 as row FROM 
(select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t,
(select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t2, 
(select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t3, 
(select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t4, 
(SELECT @row:=0) r
limit 4

which will result in

row
1.0
2.0
3.0
4.0

The rows can now be used to create a list of dates from the given start date. To include the start date we start with row -1;

select date_add('2010-01-20', interval row day) from
 ( 
    SELECT @row := @row + 1 as row FROM 
    (select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t,
    (select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t2, 
    (select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t3, 
    (select 0 union all select 1 union all select 3 union all select 4 union all select 5 union all select 6 union all select 6 union all select 7 union all select 8 union all select 9) t4, 
    (SELECT @row:=-1) r
 ) sequence
 where date_add('2010-01-20', interval row day) <= '2010-01-24'

if you will ever need more then a couple days, you need a table.

Create a date range in mysql

then,

select from days.day, count(mytable.field) as fields from days left join mytable on day=date where date between x and y;

One more solution for mysql 8.0.1 and mariadb 10.2.2 using recursive common table expressions:

with recursive dates as (
    select '2010-01-20' as date
    union all
    select date + interval 1 day from dates where date < '2010-01-24'
)
select * from dates;

A more generic answer that works in AWS MySQL.

select datetable.Date
from (
    select date_format(adddate(now(),-(a.a + (10 * b.a) + (100 * c.a))),'%Y-%m-%d') AS Date
    from (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4
     union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as a

    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4
     union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as b

    cross join (select 0 as a union all select 1 union all select 2 union all select 3 union all select 4
     union all select 5 union all select 6 union all select 7 union all select 8 union all select 9) as c
) datetable
where datetable.Date between now() - INTERVAL 14 Day and Now()
order by datetable.Date DESC

Alright.. Try this: http://www.devshed.com/c/a/MySQL/Delving-Deeper-into-MySQL-50/
http://dev.mysql.com/doc/refman/5.0/en/loop-statement.html
http://www.roseindia.net/sql/mysql-example/mysql-loop.shtml

Use that to, say, generate a temp table, and then do a select * on the temp table. Or output the results one at a time.
What you say you want to do can't be done with a SELECT statement, but it might be doable with things specific to MySQL.
Then again, maybe you need cursors: http://dev.mysql.com/doc/refman/5.0/en/cursors.html

WITH
  Digits AS (SELECT 0 D UNION SELECT 1 UNION SELECT 2 UNION SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7 UNION SELECT 8 UNION SELECT 9),
  Dates AS (SELECT adddate('1970-01-01',t4.d*10000 + t3.d*1000 + t2.d*100 + t1.d*10 +t0.d) AS date FROM Digits AS t0, Digits AS t1, Digits AS t2, Digits AS t3, Digits AS t4)
SELECT * FROM Dates WHERE date BETWEEN '2017-01-01' AND '2017-12-31'

Can create a procedure also to create calendar table with timestmap different from day. If you want a table for each quarter

e.g.

2019-01-22 08:45:00
2019-01-22 09:00:00
2019-01-22 09:15:00
2019-01-22 09:30:00
2019-01-22 09:45:00
2019-01-22 10:00:00

you can use

CREATE DEFINER=`root`@`localhost` PROCEDURE `generate_calendar_table`()
BEGIN

select unix_timestamp('2014-01-01 00:00:00') into @startts;
select unix_timestamp('2025-01-01 00:00:00') into @endts;

if ( @startts < @endts ) then

    DROP TEMPORARY TABLE IF EXISTS calendar_table_tmp;

    CREATE TEMPORARY TABLE calendar_table_tmp (ts int, dt datetime); 

    WHILE ( @startts < @endts)
        DO 
        SET @startts = @startts + 900;
        INSERT calendar_table_tmp VALUES (@startts, from_unixtime(@startts));
    END WHILE;

END if;

END


and then manipulate through

select ts, dt from calendar_table_tmp;

that give you also ts

'1548143100', '2019-01-22 08:45:00'
'1548144000', '2019-01-22 09:00:00'
'1548144900', '2019-01-22 09:15:00'
'1548145800', '2019-01-22 09:30:00'
'1548146700', '2019-01-22 09:45:00'
'1548147600', '2019-01-22 10:00:00'

from here you can start to add other information such as

select ts, dt, weekday(dt) as wd from calendar_table_tmp;

or create a real table with create table statement

Similar to D'Arcy Rittich's Answer, but for SQL SERVER

;WITH t AS
(
    SELECT n = a.n * 10 + b.n * 100 + c.n
    FROM (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) a(n)
    CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) b(n)
    CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) c(n)
)
SELECT DATEADD(DAY, t.n, '2022-01-01')
FROM t
ORDER BY T.n;

or without CTE

SELECT DATEADD(DAY, nums.n, '2022-01-01') AS d FROM (
    SELECT n = a.n * 10 + b.n * 100 + c.n
    FROM (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) a(n)
    CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) b(n)
    CROSS JOIN (VALUES (0), (1), (2), (3), (4), (5), (6), (7), (8), (9)) c(n)
) nums
order by d
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