Insert each row of stored procedure into a table - mysql

Question

I have two stored procedures in MySql. One of them does the calculation and returns everything in groups. With another stored procedure, I have a WHILE statement that runs for each month and calls the first stored procedure. I want to get the result of each group and save them in a table.
The code is something like:
CREATE PROCEDURE `first`(IN `start` date, **it should be list of items** )
begin
SET result = 0;
SELECT
item.name,
sum(amount) *INTO result*
FROM
FOO
INNER JOIN
BAR ON id = id
WHERE
date(someDate) < date(start)
group by something;
end
And the runner is something like:
CREATE PROCEDURE `runner`(IN `from` date, IN `to` date)
BEGIN
set dateTo = date(to);
set dateFrom = date(from);
WHILE DATE(dateFrom) <= DATE(dateTo) DO
call first(dateFrom, #res);
// here I need another loop through all results of the first procedure to insert each one of them in the following line.
insert into table_x (**some values which have been returned**);
SET dateFrom = DATE_ADD(dateFrom, INTERVAL 1 month);
END WHILE;
END

Answer 1

I don-' think that the loop and the second procedure ist really necessary
MySQL can't return table arrays or something of that kind, but you can use temporary tables
DELIMITER $$
CREATE PROCEDURE `first`(IN `start` date )
begin
DROP TEMPORARY TABLE IF EXISTS myTable;
CREATE TEMPORARY TABLE myTABLE
SELECT
item.name,
sum(amount)
FROM
FOO
INNER JOIN
BAR ON id = id
WHERE
date(someDate) < date(start)
group by something;
end$$
DELIMITER ;
Outer procdudre
DELIMITER $$
CREATE PROCEDURE `runner`(IN `_from` date, IN `_to` date)
BEGIN
set dateTo = date(_to);
set dateFrom = date(_from);
WHILE DATE(dateFrom) <= DATE(dateTo) DO
call first(dateFrom, #res);
insert into table_x (SELECT * FROM myTable);
SET dateFrom = DATE_ADD(dateFrom, INTERVAL 1 month);
END WHILE;
END$$
DELIMITER ;
You ca make dynamic sql work with different variables
DELIMITER $$
CREATE PROCEDURE `first`(IN `_start` date , IN _group varchar(100))
begin
DROP TEMPORARY TABLE IF EXISTS myTable;
SET #sql := CONCAT("
CREATE TEMPORARY TABLE myTABLE
SELECT
item.name,
sum(amount)
FROM
FOO
INNER JOIN
BAR ON id = id
WHERE
date(someDate) < date(",_gRoup,")
group by",_goup,";");
PREPARE stmt FROM #sql;
EXECUTE stmt;
DEALLOCATE PREPARE stmt;
end$$
DELIMITER ;

Answer 2

This might work, if all ** some values ** are replaced.
Minimal version of MySQL needed is 8.0 (or an equivalent MariaDB version).
The two variables #from and #to are set to let this script know from which data to which date is needed.
This code is untested, because OP wrote "I have two stored procedures in MySql", but he uses things like "** some values **", which make the two stored procedures invalid (sigh).
Final remark: It is, of course, possible to wrap this complete statement into a stored procedure. (If above corrections are made)
set #from = '2021-05-01';
SET #to = '2021-06-13';
insert into table_x (** some values **)
WITH recursive dates AS (
SELECT #from as d
UNION ALL
SELECT date_add(d, INTERVAL 1 DAY)
FROM dates
WHERE d<#to
)
SELECT d, **some values which have been returned**
FROM dates
CROSS JOIN (
SELECT
item.name,
sum(amount)
FROM
FOO
INNER JOIN
BAR ON id = id
WHERE
date(someDate) < date(d)
group by something) sq