Question

I have a WordPress site which has post ratings stored in the wp_ratings table, with each rating stored as an individual row. We will be changing the theme soon and need to convert the values stored in wp_ratings to meta data, which will look as follows:

a: 3: {
i: 0;
a: 2: {
    s: 7: "user_id";
    s: 1: "0";
    s: 2: "ip";
    s: 9: "127.0.0.1";
}
i: 1;
a: 2 {
    s: 7: "user_id";
    s: 1: "0";
    s: 2: "ip";
    s: 9: "127.0.0.1";
}
i: 2;
a: 2: {
    s: 7: "user_id";
    s: 1: "0";
    s: 2: "ip";
    s: 9: "127.0.0.1";
}
i: 3;
a: 2: {
    s: 7: "user_id";
    s: 1: "0";
    s: 2: "ip";
    s: 9: "127.0.0.1";
}

The total vote value is show by the a:3 at the beginning of the statement and then there is an individual entry for each rating stored.

I am not particularly familiar with stored procedures but I want to create a loop that will calculate the total value for each post in wp_posts sum(rating_rating) and then create the meta data into one long string.

I don’t really know where to start with this, so if anyone can point me in the right direction, I’d be really grateful.

Thanks

Answer 1

Setup test data

CREATE TABLE `wp_ratings` ( 
  `rating_id` INT(11) NOT NULL AUTO_INCREMENT, 
  `rating_postid` INT(11) NOT NULL, 
  `rating_posttitle` TEXT NOT NULL, 
  `rating_rating` INT(2) NOT NULL, 
  `rating_timestamp` VARCHAR(15) NOT NULL, 
  `rating_ip` VARCHAR(40) NOT NULL, 
  `rating_host` VARCHAR(200) NOT NULL, 
  `rating_username` VARCHAR(50) NOT NULL, 
  `rating_userid` INT(10) NOT NULL DEFAULT '0', 
  PRIMARY KEY  (`rating_id`), 
  KEY `rating_postid` (`rating_postid`) 
); 

INSERT INTO `test`.`wp_ratings` 
  (`rating_id`, `rating_postid`, `rating_posttitle`, 
  `rating_rating`, `rating_timestamp`, `rating_ip`, 
  `rating_host`, `rating_username`, `rating_userid`)
  VALUES
  (1,1,'title',1,'abc','127.0.0.1','a.a.a','user_id',1),
  (2,2,'title',1,'abc','127.0.0.1','a.a.a','user_id',1),
  (3,2,'title',1,'abc','127.0.0.1','a.a.a','user_id',1),
  (4,3,'title',1,'abc','127.0.0.1','a.a.a','user_id',1),
  (5,3,'title',1,'abc','127.0.0.1','a.a.a','user_id',1),
  (6,3,'title',1,'abc','127.0.0.1','a.a.a','user_id',1);

---

Query

SET @post_id = 3;

SELECT CONCAT
(
'a:', COUNT(rating_id), ':{',
    (
        SELECT CONCAT( GROUP_CONCAT(meta_data_vote SEPARATOR ''), '}') FROM
        (
            SELECT CONCAT
            ( 
                'i:',
                @curRow := @curRow + 1,
                ';a:2:{s:7:"', 
                rating_username, 
                '";s:1:"0";s:2:"ip";s:9:"', 
                rating_ip,
                '";}'
            )AS meta_data_vote
            FROM
                wp_ratings
            JOIN (SELECT @curRow := -1 AS j) r
            WHERE rating_postid = @post_id
        )AS meta_data_votes
    )
) AS new_ratings_meta_data
FROM wp_ratings l
WHERE rating_postid = @post_id

---

Result (where @post_id = 3)

a:3:{i:0;a:2:{s:7:"user_id";s:1:"0";s:2:"ip";s:9:"127.0.0.1";}i:1;a:2:{s:7:"user_id";s:1:"0";s:2:"ip";s:9:"127.0.0.1";}i:2;a:2:{s:7:"user_id";s:1:"0";s:2:"ip";s:9:"127.0.0.1";}}

---

Conclusion

I haven’t been able to write a query that returns a resultset with post_ids and their new meta_data.

The above code will only convert on a post-by-post basis.

If you want to batch update, it’ll need more thought, but i think this will get you off to a good start.