How to fetch records using vertical columns - sql

Question

I need to fetch records between the date range given in two columns.
My Table structure is like:
CREATE TABLE shared
(
id integer NOT NULL,
product varchar(50) NOT NULL,
parent_id integer NOT NULL,
key_code varchar(100) NOT NULL,
key_value varchar(8000)
);
INSERT INTO shared
(`id`, `product`, `parent_id`, 'key_code', 'key_value')
VALUES
(1, 'a',1, 'start_date','1/7/2011'),
(2, 'a', 1,'end_date','15/7/2011'),
(3, 'a',1, 'type','Promotion'),
(4, 'a',1,'plan', 'new'),
(5, 'a',5, 'start_date','11/8/2012'),
(6, 'a', 5,'end_date','15/8/2012'),
(7, 'a',5, 'type','Promotion'),
(8, 'a',5,'plan', 'new'),
(9, 'b',9, 'start_date','15/09/2015'),
(10, 'b', 9,'end_date','15/09/2016'),
(11, 'b',9, 'type','Promotion'),
(12, 'b',9,'plan', 'new'),
;
Now i want to fetch all the records between start date>='1/7/2011' to start_date<='15/8/2012' where product='a'.
The Query I tried is:
SELECT
*
FROM
(SELECT parent_id,
product,
MIN(CASE WHEN key_code = 'key_code' THEN key_value ELSE 'n/a' END) AS key_code,
MIN(CASE WHEN key_code = 'start_date' THEN key_value ELSE 'n/a' END) AS start_date,
MIN(CASE WHEN key_code = 'end_date' THEN key_value ELSE 'n/a' END) AS end_date,
MIN(CASE WHEN key_code = 'type' THEN key_value ELSE 'n/a' END) AS type,
MIN(CASE WHEN key_code = 'plan' THEN key_value ELSE 'n/a' END) AS plan,
FROM shared
GROUP BY parent_id,
product
ORDER BY parent_id) comp
WHERE
start_date>= '01/12/2011'
AND start_date <= '02/17/2011' and product='a';
I am getting records now, changed the date format.
But is there any way to optimize this query.? Like this will take time to execute when records are in numbers.

Answer 1

Your dates have not the MySQL format, so they have to be converted,to be compared
With the MIN and MAX and your 'n/a, it is better to use NULL in the inner Select and in the outer assign the Value n/a if the value is NULL, ot or else you get n/qa even if there is data.
SELECT
*
FROM
(SELECT
parent_id,
product,
MIN(CASE WHEN key_code = 'start_date' THEN key_value ELSE 'n/a' END) AS start_date,
MIN(CASE WHEN key_code = 'end_date' THEN key_value ELSE 'n/a' END) AS end_date,
MAX(CASE WHEN key_code = 'type' THEN key_value ELSE 'n/a' END) AS type,
MAX(CASE WHEN key_code = 'plan' THEN key_value ELSE 'n/a' END) AS plan
FROM
shared
GROUP BY parent_id , product
ORDER BY parent_id) comp
WHERE
TO_DATE(start_date, 'DD/MM/YYYY') >= '2011-01-12'
AND TO_DATE(start_date, 'DD/MM/YYYY') <= '2011-07-17'
AND product = 'a'
;
Thsi would give youz
parent_id product start_date end_date type plan
1 a 1/7/2011 15/7/2011 Promotion new
So STR:TO:DATE doesn't exist in AWS but it EXISTS a TO_Date
Instead of IF you maust do A CASe when like in your query