Reputation: 95
I have a problem counting ratings in SQL. This is what my data looks like:
CREATE TABLE `restaurant` (
`id_restaurant` int(11) NOT NULL AUTO_INCREMENT,
`name` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id_restaurant`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=latin1;
insert into `restaurant`(`id_restaurant`,`name`) values (1,'Mc Donald');
insert into `restaurant`(`id_restaurant`,`name`) values (2,'KFC');
CREATE TABLE `user` (
`id_user` int(11) NOT NULL AUTO_INCREMENT,
`userName` varchar(50) DEFAULT NULL,
PRIMARY KEY (`id_user`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=latin1;
insert into `user`(`id_user`,`userName`) values (1,'Audey');
CREATE TABLE `factors` (
`factor_id` int(11) NOT NULL AUTO_INCREMENT,
`factor_clean` int(11) NOT NULL DEFAULT '0',
`factor_delicious` int(11) NOT NULL DEFAULT '0',
`id_restaurant` int(11) DEFAULT NULL,
`id_user` int(11) DEFAULT NULL,
PRIMARY KEY (`factor_id`),
KEY `id_restaurant` (`id_restaurant`),
KEY `id_user` (`id_user`),
CONSTRAINT `factors_ibfk_1` FOREIGN KEY (`id_restaurant`) REFERENCES `restaurant` (`id_restaurant`),
CONSTRAINT `factors_ibfk_2` FOREIGN KEY (`id_user`) REFERENCES `user` (`id_user`)
) ENGINE=InnoDB AUTO_INCREMENT=5 DEFAULT CHARSET=latin1;
insert into `factors`(`factor_id`,`factor_clean`,`factor_delicious`,`id_restaurant`,`id_user`) values (1,1,5,1,1);
insert into `factors`(`factor_id`,`factor_clean`,`factor_delicious`,`id_restaurant`,`id_user`) values (2,0,5,1,1);
insert into `factors`(`factor_id`,`factor_clean`,`factor_delicious`,`id_restaurant`,`id_user`) values (3,1,5,1,1);
insert into `factors`(`factor_id`,`factor_clean`,`factor_delicious`,`id_restaurant`,`id_user`) values (4,3,3,1,1);
And the result should be like this, Show all ratings (1,2,3,4,5) and their count from the fields rating_clean
, rating_delicious
, and rating_clean
Thanks for your help.
but the result i get
SELECT COUNT(`factor_clean`+`factor_delicious`),'1' AS rating_1 FROM `factors` WHERE 1 GROUP BY `id_restaurant`
the result should not like that, my question is, how to select just factor_clean and factor_delicious where factor_clean =1 and factor_delicious = 1
Upvotes: 0
Views: 101
Reputation: 1270021
Use union all
to unpivot the data and then aggregate:
select id_restaurant, rating, count(*)
from ((select r.id_restaurant, r.rating_clean as rating, r.date
from ratings r
) union all
(select r.id_restaurant, r.rating_delicious, r.date
from ratings r
) union all
(select r.id_restaurant, r.rating_clean2, r.date
from ratings r
)
) r
group by id_restaurant, rating
order by id_restaurant, rating;
Upvotes: 1
Reputation: 303
For example this is solution for table with colums rating_delicious and rating_clean (only one!):
First of all you should create additional table, I called it factors:
CREATE TABLE `factors` (
`factor_id` int(11) NOT NULL AUTO_INCREMENT,
`factor_clean` int(11) NOT NULL DEFAULT '0',
`factor_delicious` int(11) NOT NULL DEFAULT '0',
PRIMARY KEY (`factor_id`)
)
Next add two records:
INSERT INTO `factors` (`factor_id`, `factor_clean`, `factor_delicious`) VALUES (NULL, '1', '0'), (NULL, '0', '1');
Now you can join this tables and get results:
SELECT x.id_restaurant
, (x.rating_clean * f.factor_clean) + (x.rating_delicious * f.factor_delicious) AS rating
, count(*)
FROM your_table x
JOIN factors f
WHERE 1
GROUP
BY x.id_restaurant
, rating
In order to use next colum (rating_third
), you should and column factor_third
to factors
, insert new row with 1
in this column and finally add something like your_table.rating_third*factors.factor_third
to sum in SELECT
Upvotes: 0