MySQL 8.0

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select version();


version()


8.0.27


CREATE TABLE products
(product_name VARCHAR(3),list_price INT);

INSERT INTO products VALUES('AAA',800),('BBB',750),('CCC',650);



CREATE PROCEDURE test( OUT message VARCHAR(200) )
BEGIN
DECLARE product_name_var VARCHAR(50);
DECLARE list_price_var DECIMAL(9,2);
DECLARE row_not_found TINYINT DEFAULT FALSE;
DECLARE s_var VARCHAR(400) DEFAULT '';

DECLARE invoice_cursor CURSOR for
    SELECT 
        product_name,
        list_price
    FROM
        products
    WHERE
        list_price > 700
    ORDER BY list_price DESC;
    
DECLARE CONTINUE HANDLER FOR NOT FOUND
    SET row_not_found = TRUE;

OPEN invoice_cursor;

FETCH invoice_cursor INTO product_name_var, list_price_var;
WHILE row_not_found = FALSE DO

SET s_var = CONCAT(s_var,'*', product_name_var,'*,*',list_price_var,'*|');
    FETCH invoice_cursor INTO product_name_var, list_price_var;
END WHILE;
SET message = s_var ;
#SELECT s_var AS message;
END 



CALL test(@A);

SELECT @A


@A


*AAA*,*800.00*|*BBB*,*750.00*|