mysql generate EMI pay date list - mysql

If my current_date ='2020-01-17' and Emi=5
generate dates like
1)2020-02-17
2)2020-03-17
3)2020-04-17
4)2020-05-17
5)2020-06-17
current_date ='2020-01-30' and Emi=3
generate dates like
1)2020-02-28
2)2020-03-30
3)2020-04-30
current_date = '2020-01-31' and emi=3
generate dates like
1)2020-02-28
2)2020-03-31
3)2020-04-30
could you please anybody help me to generate the date then insert to the table?


create procedure generate_EMI_pay_date_list(start_date date, records_count int)
with recursive
cte as (select 1 num
union all
select num+1
from cte
where num < records_count)
select start_date + interval num month
from cte;
call generate_EMI_pay_date_list(current_date, 5);
call generate_EMI_pay_date_list('2020-01-30', 3);
call generate_EMI_pay_date_list('2020-01-31', 3);
but my server MySQL version is 5.6.51 – Murugan
#Murugan What is maximal possible value for your Emi parameter (max. amount of rows to be generated)? – Akina
max 48 rows.... – Murugan
CREATE PROCEDURE generate_EMI_pay_date_list(start_date DATE, records_count INT)
SELECT start_date + INTERVAL num1.num * 7 + num2.num MONTH
FROM (SELECT 0 num UNION SELECT 1 UNION SELECT 2 UNION
SELECT 3 UNION SELECT 4 UNION SELECT 5 UNION SELECT 6) num1
JOIN (SELECT 1 num UNION SELECT 2 UNION SELECT 3 UNION
SELECT 4 UNION SELECT 5 UNION SELECT 6 UNION SELECT 7) num2
WHERE num1.num * 7 + num2.num <= records_count;

Related

MySQL Select range date between two columns without using table columns

In My sql I want to get the date differences between two dates without using table columns
For example
SELECT BETWEEN '2012-01-10' AND '2012-01-15' as date1;
I have to get the following date as output
'2012-01-11'
'2012-01-12'
'2012-01-13'
'2012-01-14'
how to write a query to get the output as above

WITH RECURSIVE
cte AS ( SELECT #startdate + INTERVAL 1 DAY `date`
UNION ALL
SELECT `date`+ INTERVAL 1 DAY
FROM cte
WHERE `date` < #enddate - INTERVAL 1 DAY )
SELECT *
FROM cte
fiddle
MySQL 8+ needed.
my sql version used 5.6
maximum 1 year
SELECT #startdate + INTERVAL (n3.num * 7 * 7 + n2.num * 7 + n1.num + 1) DAY `date`
FROM ( SELECT 0 num union select 1 union select 2 union select 3
union select 4 union select 5 union select 6) n1
JOIN ( SELECT 0 num union select 1 union select 2 union select 3
union select 4 union select 5 union select 6) n2
JOIN ( SELECT 0 num union select 1 union select 2 union select 3
union select 4 union select 5 union select 6 union select 7) n3
HAVING `date` < #enddate;
fiddle
Max. period length is 7 * 7 * 8 = 392 days.

If you are running MySQL 8.0, you can do this with a recursive query:
with recursive cte as (
select '2012-01-10' + interval 1 day as dt
union all
select dt + interval 1 day from cte where dt + interval 1 day < '2012-01-15'
)
select * from cte
This generates one row per date in between the bounds given as input.

Mysql View where a value is split over multiple rows according to date

MySql version: 5.6.47
Assuming I have a table like this:
[from:Datetime][to:Datetime][amount:Decimal(10,2)]
[2020/01/15 ][2020/02/15 ][300 ]
I want to create a view like this out of it:
[period:char(7)][amount:Decimal(10,2)]
[2020/01 ][150 ]
[2020/02 ][150 ]
The from and to dates are split up in the singular months. The amount is multiplied with the amount of days in that particular month over the total amount of days between from and to. From and to could span n amount of month.
Is that even possible or am I wasting my time researching this?

Assuming that the amount of months in a range is not over 100:
SELECT id,
datefrom,
datetill,
amount,
monthstart,
monthfinish,
amount * (DATEDIFF(LEAST(datetill, monthfinish), GREATEST(datefrom, monthstart)) + 1) / (DATEDIFF(datetill, datefrom) + 1) monthamount
FROM ( SELECT test.*,
(test.datefrom - INTERVAL DAY(test.datefrom) - 1 DAY) + INTERVAL numbers.num MONTH monthstart,
LAST_DAY((test.datefrom - INTERVAL DAY(test.datefrom) - 1 DAY) + INTERVAL numbers.num MONTH) monthfinish
FROM test
JOIN ( SELECT t1.num*10+t2.num num
FROM (SELECT 0 num 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
JOIN (SELECT 0 num 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
) numbers
HAVING monthstart <= test.datetill
AND monthfinish >= test.datefrom
) subquery
ORDER BY id, monthstart;
fiddle
PS. Don't be surprised if the total sum doesn't match in the last digit.

Best way to generate records for each day for the week for the whole year MySQL [duplicate]

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)?

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

I did not want my SQL query to require external dependencies (needing to have a calendar table, procedure for populating a temporary table with dates, etc.) The original idea for this query came from http://jeffgarretson.wordpress.com/2012/05/04/generating-a-range-of-dates-in-mysql/ which I had slightly optimized for clarity and ease of use.
SELECT (CURDATE() - INTERVAL c.number DAY) AS date
FROM (SELECT singles + tens + hundreds number FROM
( SELECT 0 singles
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
) singles JOIN
(SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
ORDER BY number DESC) c
WHERE c.number BETWEEN 0 and 364
It is simple to optimize and scale this table for other uses. You can easily get rid of the tens and hundreds tables if you only need one week of data.
If you need a larger set of numbers, it is easy to add a thousands table. You only need to copy and paste the table with hundreds and add a zero to 9 numbers.

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 adddate('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'

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');

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.

If you have a table with a large enough contiguous set of ids you could use -
INSERT INTO tablename (_date)
SELECT '2011-01-01' + INTERVAL (id - 1) DAY
FROM some_table_with_lots_of_ids
WHERE id BETWEEN 1 AND 365
note: but be aware that this might get you in trouble during leap-years (having 366 days)

This can be achieved in PHP by using a simple for loop. There are a couple of ways to do it. One way would be to to place the original date in a variable and have the loop run through it for every day by adding +1 day on each loop, for instance, you'll start on 01/01/2011 and then the loop will add 0 the first time, 1 day the next, followed by 2 days so forth and so forth to the $i variable. You could then print out the days or add them to your database. In this case $i would represent the counter with 0 being the starting point, <=365 is how many loops you want to go through which is equal to or less than the number of days and $i++ adds +1 to the $i variable on each loop.
date('Y-m-d' converts the date into yyyy-mm-dd. Using a capital Y gives you a full 4 digit year whereas using a lower case y will give you the last 2 digits of the year. You want to keep it in this order to add it in a date field in mySQL.
strtotime($originalDate parses the date into a Unix time stamp and the ."+".$i." day") basically adds the value of $i in days to the date.
Finally there's the mysqli query. $db represents the database connection variable, this will need to be changed to whatever variable you have set for the connection. This is followed by the actual query. Just exchange the word table for your table name and the date before VALUES to you date row name and you're ready to go.
The following is an example:
<?php
for($i=0;$i<=365;$i++){
$originalDate = "01/01/2011";
$date = date('Y-m-d',strtotime($originalDate . "+".$i." day"));
mysqli_query($db, "INSERT INTO table (date)VALUES('$date')");
}
Another way to achieve this using the for function would be to include the strtotime dates directly in the for actions as an oppose to the counter variables, which is an even shorter piece of code. Replace $i=0 (the starting counter point) with the starting day point, follow that with the less than or equal to the end day point (the number of loops) then finally with your plus +1 to the first statement placed into a variable ready for use.
Finally, convert the date into Y-m-d format ready to be placed into the database and run the query.
Again, as with the first example, this can be printed or placed directly into your database.
The following is an example:
<?php
for ($startdate = strtotime("2011-01-01"); $startdate <= strtotime("2011-12-31"); $startdate = strtotime("+1 day", $startdate)) {
$date= date("Y-m-d", $startdate);
mysqli_query($db, "INSERT INTO tracking (date)VALUES('$date')");
}
I've probably made it sound more confusing than it is, but hope it will at least give you an idea on how it works.

Thanks to IvanD.
I've got a better solution which allowes you to create a specified calendar table.
For example, if I'm trying to create a table of 2014-04, it looks like this:
SELECT (CURDATE() - INTERVAL c.number DAY) AS DATE
FROM
(
SELECT singles + tens + hundreds number FROM
(
SELECT 0 singles
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
) singles JOIN
(
SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(
SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
ORDER BY number DESC
) c
WHERE c.number BETWEEN
DAYOFYEAR(NOW()) - DAYOFYEAR('2014-04-01')- DAY(LAST_DAY('2014-04-01')) +1
AND
DAYOFYEAR(NOW()) - DAYOFYEAR('2014-04-01')

Inspired by IvanD`s great number join i come to this:
SELECT DATE_ADD('2015-10-21', INTERVAL c.number DAY) AS DATE
FROM
(
SELECT singles + tens + hundreds+thousands number FROM
(
SELECT 0 singles
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
) singles JOIN
(
SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(
SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
JOIN
(
SELECT 0 thousands
UNION ALL SELECT 1000 UNION ALL SELECT 2000 UNION ALL SELECT 3000
UNION ALL SELECT 4000 UNION ALL SELECT 5000 UNION ALL SELECT 6000
UNION ALL SELECT 7000 UNION ALL SELECT 8000 UNION ALL SELECT 9000
) thousands
ORDER BY number DESC
) c
WHERE c.number BETWEEN
0
AND
DATEDIFF('2016-10-08', '2015-10-21')

INSERT INTO my_dates (\`_date\`) SELECT DATE_ADD('2011-01-01', INTERVAL #_tmp:=#_tmp+1 day) \`_date\`
FROM (SELECT #_tmp:=-1 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) a /\*10^1\*/
JOIN (SELECT 0 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) b /\*10^2\*/
JOIN (SELECT 0 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) c /\*10^3\*/
WHERE #_tmp+1 BETWEEN 0 AND DATEDIFF('2011-12-31', '2011-01-01');

Create a table with every month since given date [duplicate]

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)?

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

I did not want my SQL query to require external dependencies (needing to have a calendar table, procedure for populating a temporary table with dates, etc.) The original idea for this query came from http://jeffgarretson.wordpress.com/2012/05/04/generating-a-range-of-dates-in-mysql/ which I had slightly optimized for clarity and ease of use.
SELECT (CURDATE() - INTERVAL c.number DAY) AS date
FROM (SELECT singles + tens + hundreds number FROM
( SELECT 0 singles
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
) singles JOIN
(SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
ORDER BY number DESC) c
WHERE c.number BETWEEN 0 and 364
It is simple to optimize and scale this table for other uses. You can easily get rid of the tens and hundreds tables if you only need one week of data.
If you need a larger set of numbers, it is easy to add a thousands table. You only need to copy and paste the table with hundreds and add a zero to 9 numbers.

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 adddate('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'

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');

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.

If you have a table with a large enough contiguous set of ids you could use -
INSERT INTO tablename (_date)
SELECT '2011-01-01' + INTERVAL (id - 1) DAY
FROM some_table_with_lots_of_ids
WHERE id BETWEEN 1 AND 365
note: but be aware that this might get you in trouble during leap-years (having 366 days)

This can be achieved in PHP by using a simple for loop. There are a couple of ways to do it. One way would be to to place the original date in a variable and have the loop run through it for every day by adding +1 day on each loop, for instance, you'll start on 01/01/2011 and then the loop will add 0 the first time, 1 day the next, followed by 2 days so forth and so forth to the $i variable. You could then print out the days or add them to your database. In this case $i would represent the counter with 0 being the starting point, <=365 is how many loops you want to go through which is equal to or less than the number of days and $i++ adds +1 to the $i variable on each loop.
date('Y-m-d' converts the date into yyyy-mm-dd. Using a capital Y gives you a full 4 digit year whereas using a lower case y will give you the last 2 digits of the year. You want to keep it in this order to add it in a date field in mySQL.
strtotime($originalDate parses the date into a Unix time stamp and the ."+".$i." day") basically adds the value of $i in days to the date.
Finally there's the mysqli query. $db represents the database connection variable, this will need to be changed to whatever variable you have set for the connection. This is followed by the actual query. Just exchange the word table for your table name and the date before VALUES to you date row name and you're ready to go.
The following is an example:
<?php
for($i=0;$i<=365;$i++){
$originalDate = "01/01/2011";
$date = date('Y-m-d',strtotime($originalDate . "+".$i." day"));
mysqli_query($db, "INSERT INTO table (date)VALUES('$date')");
}
Another way to achieve this using the for function would be to include the strtotime dates directly in the for actions as an oppose to the counter variables, which is an even shorter piece of code. Replace $i=0 (the starting counter point) with the starting day point, follow that with the less than or equal to the end day point (the number of loops) then finally with your plus +1 to the first statement placed into a variable ready for use.
Finally, convert the date into Y-m-d format ready to be placed into the database and run the query.
Again, as with the first example, this can be printed or placed directly into your database.
The following is an example:
<?php
for ($startdate = strtotime("2011-01-01"); $startdate <= strtotime("2011-12-31"); $startdate = strtotime("+1 day", $startdate)) {
$date= date("Y-m-d", $startdate);
mysqli_query($db, "INSERT INTO tracking (date)VALUES('$date')");
}
I've probably made it sound more confusing than it is, but hope it will at least give you an idea on how it works.

Thanks to IvanD.
I've got a better solution which allowes you to create a specified calendar table.
For example, if I'm trying to create a table of 2014-04, it looks like this:
SELECT (CURDATE() - INTERVAL c.number DAY) AS DATE
FROM
(
SELECT singles + tens + hundreds number FROM
(
SELECT 0 singles
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
) singles JOIN
(
SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(
SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
ORDER BY number DESC
) c
WHERE c.number BETWEEN
DAYOFYEAR(NOW()) - DAYOFYEAR('2014-04-01')- DAY(LAST_DAY('2014-04-01')) +1
AND
DAYOFYEAR(NOW()) - DAYOFYEAR('2014-04-01')

Inspired by IvanD`s great number join i come to this:
SELECT DATE_ADD('2015-10-21', INTERVAL c.number DAY) AS DATE
FROM
(
SELECT singles + tens + hundreds+thousands number FROM
(
SELECT 0 singles
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
) singles JOIN
(
SELECT 0 tens
UNION ALL SELECT 10 UNION ALL SELECT 20 UNION ALL SELECT 30
UNION ALL SELECT 40 UNION ALL SELECT 50 UNION ALL SELECT 60
UNION ALL SELECT 70 UNION ALL SELECT 80 UNION ALL SELECT 90
) tens JOIN
(
SELECT 0 hundreds
UNION ALL SELECT 100 UNION ALL SELECT 200 UNION ALL SELECT 300
UNION ALL SELECT 400 UNION ALL SELECT 500 UNION ALL SELECT 600
UNION ALL SELECT 700 UNION ALL SELECT 800 UNION ALL SELECT 900
) hundreds
JOIN
(
SELECT 0 thousands
UNION ALL SELECT 1000 UNION ALL SELECT 2000 UNION ALL SELECT 3000
UNION ALL SELECT 4000 UNION ALL SELECT 5000 UNION ALL SELECT 6000
UNION ALL SELECT 7000 UNION ALL SELECT 8000 UNION ALL SELECT 9000
) thousands
ORDER BY number DESC
) c
WHERE c.number BETWEEN
0
AND
DATEDIFF('2016-10-08', '2015-10-21')

INSERT INTO my_dates (\`_date\`) SELECT DATE_ADD('2011-01-01', INTERVAL #_tmp:=#_tmp+1 day) \`_date\`
FROM (SELECT #_tmp:=-1 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) a /\*10^1\*/
JOIN (SELECT 0 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) b /\*10^2\*/
JOIN (SELECT 0 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) c /\*10^3\*/
WHERE #_tmp+1 BETWEEN 0 AND DATEDIFF('2011-12-31', '2011-01-01');

Fill missing values with 0 - sql query

I have an SQL query as outlined below that selects data between two dates.
SELECT date, total FROM db WHERE date >= '2016-03-14' AND date <= '2016-03-20';
I'd like to output a "0" where there's no data for various dates, for example:
Query spans = 2016-03-14 to 2016-03-20
Currently my SQL would output:
Date Total
2016-03-14 50
I'd like to output:
Date Total
2016-03-14 50
2016-03-15 0
2016-03-16 0
2016-03-17 0
2016-03-18 0
2016-03-19 0
2016-03-20 0
Is there any way to do this without complex joins?
Thanks,
Matt

The best way to create records for dates that don't exist in your data is to join to a calendar table.
SELECT a.cal_dt, COALESCE(b.total,0) AS total
FROM lkp_Calendar a
LEFT JOIN db b
ON b.date = a.cal_dt
WHERE a.cal_dt >= '2016-03-14'
AND a.cal_dt <= '2016-03-20';
There are many good scripts out there to create robust calendar tables, a simple one is:
CREATE TABLE lkp_Calendar (cal_dt date);
CREATE PROCEDURE addDates(dateStart DATE, dateEnd DATE)
BEGIN
WHILE dateStart <= dateEnd DO
INSERT INTO lkp_Calendar (cal_dt) VALUES (dateStart);
SET dateStart = date_add(dateStart, INTERVAL 1 DAY);
END WHILE;
END;
CALL addDates('2016-01-01','2016-12-31');

SELECT date, COUNT(*) AS total FROM db WHERE date >= '2016-03-14' AND date <= '2016-03-20' GROUP BY date;
I assume:
date is just a date (has no time part)
total IS NOT a column, just a register count

It doesn't require complex joins. But it does require a rowsource for the missing date values you want returned.
One option is to use a calendar table populated with dates.
create table cal (dt DATE NOT NULL PRIMARY KEY) ... ;
insert into cal (dt) values ('2016-03-01');
insert into cal (dt) select dt + interval 1 day from cal order by dt;
insert into cal (dt) select dt + interval 2 day from cal order by dt;
insert into cal (dt) select dt + interval 4 day from cal order by dt;
insert into cal (dt) select dt + interval 8 day from cal order by dt;
insert into cal (dt) select dt + interval 16 day from cal order by dt;
Then pull the dates from that:
SELECT c.dt
FROM cal c
WHERE c.dt >= '2016-03-14'
AND c.dt < '2016-03-21'
Then just do the simple outer join to your table:
SELECT c.dt AS `date`
, IFNULL(d.total,0) AS `total`
FROM cal c
LEFT
JOIN db d
ON d.date = c.dt
WHERE c.dt >= '2016-03-14'
AND c.dt < '2016-03-21'
ORDER BY c.dt
If you don't have a calendar table, you can use an inline view that does UNION ALL
SELECT c.dt AS `date`
, IFNULL(d.total,0) AS `total`
FROM ( SELECT '2016-03-14' + INTERVAL 0 DAY AS dt
UNION ALL SELECT '2016-03-15' + INTERVAL 0 DAY
UNION ALL SELECT '2016-03-16' + INTERVAL 0 DAY
UNION ALL SELECT '2016-03-17' + INTERVAL 0 DAY
UNION ALL SELECT '2016-03-18' + INTERVAL 0 DAY
UNION ALL SELECT '2016-03-19' + INTERVAL 0 DAY
UNION ALL SELECT '2016-03-20' + INTERVAL 0 DAY
) c
LEFT
JOIN db d
ON d.date = c.dt
ORDER BY c.dt

You can also try the below query. This caters for the scenario where you don't have records for all the dates in the underlying table.
DECLARE #temp TABLE (dbdate DATE, total INT)
DECLARE #StartDate DATE = '2016-03-14'
DECLARE #EndDate DATE = '2016-03-20'
WHILE (#StartDate <= #EndDate)
BEGIN
INSERT #temp
SELECT #StartDate AS [dbDate], ISNULL((SELECT total FROM db WHERE [date] = #StartDate),0) AS Total
SET #StartDate = DATEADD(dd,1,#StartDate)
END
SELECT * FROM #temp

Try this (The fiddle demo is slightly different as I didn't have data of db table)
SQLFiddle Demo
select selected_date,coalesce(count1,0) as count1 from
(select * from
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
(select 0 i 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 i 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 i 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 i 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 i 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 selected_date between '2016-03-14' and '2016-03-20'
) t
left join
(SELECT dt, count1 FROM db WHERE dt between '2016-03-14' and '2016-03-20') t1
on t.selected_date=t1.dt