How to populate a table with a range of dates?

Question

I need a MySQL table to hold ALL DATES between 2011-01-01 and 2011-12-31. I have created a table with one column names "_date", type DATE.

With what query can I populate the table with all the desired dates (instead of having to enter them by hand)?

Answer 1

if you're in a situation like me where procedures are prohibited, and your sql user does not have permissions for insert, therefore insert not allowed, but you want to generate a list of dates in a specific period, say current year to do some aggregation, use this

select * from 
(select affffdate('1970-01-01',t4*10000 + t3*1000 + t2*100 + t1*10 + t0) gen_date from
 (select 0 t0 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) t0,
 (select 0 t1 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) t1,
 (select 0 t2 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) t2,
 (select 0 t3 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) t3,
 (select 0 t4 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) t4) v
where gen_date between '2017-01-01' and '2017-12-31'

Answer 2

Try this:

DROP PROCEDURE IF EXISTS filldates;
DELIMITER |
CREATE PROCEDURE filldates(dateStart DATE, dateEnd DATE)
BEGIN
  WHILE dateStart <= dateEnd DO
    INSERT INTO tablename (_date) VALUES (dateStart);
    SET dateStart = date_add(dateStart, INTERVAL 1 DAY);
  END WHILE;
END;
|
DELIMITER ;
CALL filldates('2011-01-01','2011-12-31');

Here's the SQL Fiddle to play with it: http://sqlfiddle.com/#!2/65d13/1

EDIT (to check if date already exists) as asked by Andrew Fox.

CREATE PROCEDURE filldates(dateStart DATE, dateEnd DATE)

BEGIN

DECLARE adate date;

    WHILE dateStart <= dateEnd DO

        SET adate = (SELECT mydate FROM MyDates WHERE mydate = dateStart);

        IF adate IS NULL THEN BEGIN

            INSERT INTO MyDates (mydate) VALUES (dateStart);

        END; END IF;

        SET dateStart = date_add(dateStart, INTERVAL 1 DAY);

    END WHILE;

END;//

Here's the SQL Fiddle to play with it: http://sqlfiddle.com/#!2/66f86/1

Answer 3

I found this paste-and-go variant working:

DROP PROCEDURE IF EXISTS FillCalendar;
DROP TABLE IF EXISTS calendar;
CREATE TABLE IF NOT EXISTS calendar(calendar_date DATE NOT NULL PRIMARY KEY);

DELIMITER $$
    CREATE PROCEDURE FillCalendar(start_date DATE, end_date DATE)
    BEGIN
    DECLARE crt_date DATE;
    SET crt_date = start_date;
    WHILE crt_date <= end_date DO
        INSERT IGNORE INTO calendar VALUES(crt_date);
        SET crt_date = ADDDATE(crt_date, INTERVAL 1 DAY);
    END WHILE;
    END$$
DELIMITER ;

CALL FillCalendar('2013-01-01', '2013-01-03');
CALL FillCalendar('2013-01-01', '2013-01-07');

Answer 4

I recently had a need to create a calendar_date table as below:

CREATE TABLE `calendar_date` (
    `date`    DATE NOT NULL      -- A calendar date.
    , `day`   SMALLINT NOT NULL  -- The day of the year for the date, 1-366.
    , `month` TINYINT NOT NULL   -- The month number, 1-12.
    , `year`  SMALLINT NOT NULL  -- The year.
    , PRIMARY KEY (`id`));

I then populated it with all possible dates between January 1, 2001 and December 31, 2100 (both inclusive) using the query below:

INSERT INTO `calendar_date` (`date`
    , `day`
    , `month`
    , `year`)
SELECT
    DATE
    , INCREMENT + 1
    , MONTH(DATE)
    , YEAR(DATE)
FROM
    -- Generate all possible dates for every year from 2001 to 2100.
    (SELECT
        DATE_ADD(CONCAT(YEAR, '-01-01'), INTERVAL INCREMENT DAY) DATE
        , INCREMENT
    FROM
        (SELECT
            (UNITS + TENS + HUNDREDS) INCREMENT
        FROM
            (SELECT 0 UNITS 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) UNITS
        CROSS JOIN
            (SELECT 0 TENS UNION
            SELECT 10 UNION SELECT 20 UNION SELECT 30 UNION
            SELECT 40 UNION SELECT 50 UNION SELECT 60 UNION
            SELECT 70 UNION SELECT 80 UNION SELECT 90) TENS
        CROSS JOIN
            (SELECT 0 HUNDREDS UNION
            SELECT 100 UNION SELECT 200 UNION SELECT 300 UNION
            SELECT 400 UNION SELECT 500 UNION SELECT 600 UNION
            SELECT 700 UNION SELECT 800 UNION SELECT 900) HUNDREDS
        ) INCREMENT
        -- For every year from 2001 to 2100, find the number of days in the year.
        , (SELECT
            YEAR
            , DAYOFYEAR(CONCAT(YEAR, '-12-31')) - DAYOFYEAR(CONCAT(YEAR, '-01-01')) + 1 DAYS
        FROM
            -- Generate years from 2001 to 2100.
            (SELECT
                (2000 + UNITS + TENS) YEAR
            FROM
                (SELECT 0 UNITS 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) UNITS
            CROSS JOIN
                (SELECT 0 TENS UNION
                SELECT 10 UNION SELECT 20 UNION SELECT 30 UNION
                SELECT 40 UNION SELECT 50 UNION SELECT 60 UNION
                SELECT 70 UNION SELECT 80 UNION SELECT 90) TENS
            ) YEAR
        WHERE
            YEAR BETWEEN 2001 AND 2100
        ) YEAR
      WHERE
          INCREMENT BETWEEN 0 AND DAYS - 1
      ORDER BY
          YEAR
          , INCREMENT) DATE;

On my local MySQL database, the INSERT query took just a few seconds. Hope this helps someone.