MySQL 8.0

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CREATE TABLE Calendar (
    cDate datetime, 
    cDay int, 
    cDayOfWeek int, 
    cDayName varchar(20)
);
CREATE PROCEDURE filldates(dateStart DATE, dateEnd DATE)
BEGIN
  WHILE dateStart <= dateEnd DO
    INSERT INTO Calendar (cDate, cDayOfWeek, cDayName) 
    VALUES (dateStart, DAYOFWEEK(dateStart), DAYNAME(dateStart));
    SET dateStart = date_add(dateStart, INTERVAL 1 DAY);
  END WHILE;
END;
CALL filldates('2018-01-01','2018-12-31');
CREATE TABLE `daily_stats` (
  `id` bigint(20) unsigned NOT NULL AUTO_INCREMENT,
  `date` date NOT NULL,
  `stat` int(11) NOT NULL,
  `value` bigint(20) unsigned NOT NULL,
  `created_at` timestamp NULL DEFAULT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `daily_stats_date_stat_unique` (`date`,`stat`)
)
INSERT INTO daily_stats (`date`, `stat`, `value`, `created_at`)
SELECT
    cDate, 0, 0, now()
FROM 
    Calendar 
WHERE 
    cDayOfWeek = 7;

Records: 52  Duplicates: 0  Warnings: 0


SELECT * FROM daily_stats LIMIT 10;


id
date
stat
value
created_at
updated_at


1
2018-01-06
0
0
2022-10-19 17:03:07
null

2
2018-01-13
0
0
2022-10-19 17:03:07
null

3
2018-01-20
0
0
2022-10-19 17:03:07
null

4
2018-01-27
0
0
2022-10-19 17:03:07
null

5
2018-02-03
0
0
2022-10-19 17:03:07
null

6
2018-02-10
0
0
2022-10-19 17:03:07
null

7
2018-02-17
0
0
2022-10-19 17:03:07
null

8
2018-02-24
0
0
2022-10-19 17:03:07
null

9
2018-03-03
0
0
2022-10-19 17:03:07
null

10
2018-03-10
0
0
2022-10-19 17:03:07
null

id	date	created_at	updated_at
1	2018-01-06	2022-10-19 17:03:07	null
2	2018-01-13	2022-10-19 17:03:07	null
3	2018-01-20	2022-10-19 17:03:07	null
4	2018-01-27	2022-10-19 17:03:07	null
5	2018-02-03	2022-10-19 17:03:07	null
6	2018-02-10	2022-10-19 17:03:07	null
7	2018-02-17	2022-10-19 17:03:07	null
8	2018-02-24	2022-10-19 17:03:07	null
9	2018-03-03	2022-10-19 17:03:07	null
10	2018-03-10	2022-10-19 17:03:07	null