here is a little background on what I'm trying to accomplish. I have an array from a MySQL query that is being displayed. I want to sort the array based on a factor. The factor is calculated inline based on the time the article was posted & the number of votes it's received. Something like this:
// ... MySQL query here
$votes = $row['0']
$seconds = strtotime($record->news_time)+time();
$sum_total = pow($votes,2) / $seconds;
So the array thats coming in looks something like this:
Array (
[0] => stdClass Object (
[id] => 13
[news_title] => Article
[news_url] => http://website.com/article/14
[news_root_domain] => website.com
[news_category] => Business
[news_submitter] => 2
[news_time] => 2013-02-18 12:50:02
[news_points] => 2
)
[1] => stdClass Object (
[id] => 14
[news_title] => Title
[news_url] => http://www.website.com/article/2
[news_root_domain] => www.website.com
[news_category] => Technology
[news_submitter] => 1
[news_time] => 2012-10-02 10:03:22
[news_points] => 8
)
)
I want to sort the aforementioned array using the factor I mentioned above. The idea is to show the highest rated articles first on the list (using the calculated factor), instead of the default sorting method that the array comes in. It seems like usort might be my best bet, but let me know what you all think?
Do it all in the query:
SELECT n.*, ( POW(?, 2) / (UNIX_TIMESTAMP(n.news_time) + UNIX_TIMESTAMP(NOW())) ) as rank
FROM news_table n
ORDER BY rank;
Now in order to get the votes you may have to do a subquery or a join, but i cant advise on that because you dont give enough info on where the votes are coming from. You could however supply the votes to the query as well instead of selecting it all in one shot something like:
$sql = sprintf('SELECT n.*, ( POW(%d, 2) / (UNIX_TIMESTAMP(n.news_time) + UNIX_TIMESTAMP(NOW())) ) as rank FROM news_table n ORDER BY rank', $votes);
Aside from that, yes you could use usort, but that would also require you to have the entire recordset in memory to provide accurate sorting, which could be problematic at some point.
Related
Please help me to resolve this issue
i want to get the less size PandaCode as the output and i have an PandaCode
Array
(
[0] => 37860
[1] => 37016
[2] => 37013
[3] => 38220
[4] => 38420
[5] => 38223
)
Each PandaCode code have multiple ids
for example 37860 have count(id)=3 like this each Pandacodehave id with count of different values but i want to get the PandaCode which is having less count of id as the output
foreach($pandacode as $dealer_code){
$query="SELECT COUNT(id) FROM `dealer_details`
WHERE `PandaCode` like '$dealer_code' and `Senttime` like '%$today%'";
$result=mysqli_query($conn,$query);
$row = $result->fetch_assoc();
$size = $row['COUNT(id)'];
}
if i understand your issue in right way than you to add whereIn instead of for each, try this
SELECT COUNT(id) as ids FROM `dealer_details` WHERE `PandaCode` IN ($pandacode) and `Senttime` like '%$today%' GROUP BY `PandaCode` ORDER BY ids ASC LIMIT 1
on my ratings table for my software i have 4 fields.
id autoincrement
rvid vendor id
ratedate date of rating
rating the actual numeric rating
I have done alot with it over the last few months but this time im stumped and i cant get a clear picture in my head of the best way to do this. What i am trying to do is find out if the vendor has had 3 low 'consecutive' ratings. If their last three ratings have been < 3 then i want to flag them.
I have been playing with this for a few hours now so i thought i would ask (not for the answer) but for some path direction just to push me forward, im stuck in thought going in circles here.
I have tried GROUP BY and several ORDER BY but those attempts did not go well and so i am wondering if this is not a mysql answer but a php answer. In other words maybe i just need to take what i have so far and just move to the php side of things via usort and the like and do it that way.
Here is what i have so far i did select id as well at first thinking that was the best way to get the last consective but then i had a small breakthrough that if they have had 3 in a row the id does not matter, so i took it out of the query.
$sql = "SELECT `rvid`, `rating` FROM `vendor_ratings_archive` WHERE `rating` <= '3' ORDER BY `rvid` DESC";
which give me this
Array
(
[0] => Array
(
[rvid] => 7
[rating] => 2
)
[1] => Array
(
[rvid] => 5
[rating] => 1
)
[2] => Array
(
[rvid] => 5
[rating] => 0
)
[3] => Array
(
[rvid] => 5
[rating] => 3
)
)
this is just just samples i tossed in the fields, and there are only 4 rows here where as in live it will be tons of rows. But basically this tells me that these are the vendors that have low ratings in the table. And that is where i get stumpted. I can only do one sort in the query so that is why i am thinking that i need to take this and move to the php side to finish it off.
I think i need to sort the elements by rvid with php first i think, and then see if three elements in a row are the same vender (rvid).
Hope that makes sense. My brain hurts lol...
update - here is all of the table data using *
Array
(
[0] => Array
(
[id] => 7
[rvid] => 7
[ratedate] => 2016-05-01
[rating] => 2
)
[1] => Array
(
[id] => 8
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 1
)
[2] => Array
(
[id] => 6
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 0
)
[3] => Array
(
[id] => 5
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 3
)
)
Here's one way you can begin approaching this - completely in SQL:
Get the last rating for the vendor. ORDER BY date DESC, limit 1.
Get the second to last rating for the vendor. ORDER BY date DESC, limit 1, OFFSET 1.
Then write a query that does a LEFT join of the first two tables. You will have a dataset that has three columns:
vendor id
last rating
second to last rating
Then you can write an expression that says "if column1 is <3 and column2 < 3, then this new column is true"
You should be able to extend this to three columns relatively easily.
Here is what a came up with to solve this riddle. I think explaining it on here helped as well as Alex also helped as he keyed my brain on using the date. I first started looking at using if statment inside of the query and actually that got my brain out of the box and then it hit me what to do.
It is not perfect and certainly could use some trimming to reduce the code, but i understand it and it seems to work, so that is par for me on this course.
the query...
$sql = "SELECT `rvid`, `ratedate`,`rating` FROM `vendor_ratings_archive` WHERE `rating` <= '3' ORDER BY `ratedate`, `rvid` DESC";
which gives me this
Array
(
[0] => Array
(
[rvid] => 7
[ratedate] => 2016-05-01
[rating] => 2
)
[1] => Array
(
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 1
)
[2] => Array
(
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 0
)
[3] => Array
(
[rvid] => 5
[ratedate] => 2016-05-01
[rating] => 3
)
)
notice how vendor (rvid) 5 is grouped together which is an added plus.
next a simple foreach to load a new array
foreach($results as $yield)
{
$rvidarray[] = $yield['rvid'];
}//close foreach
which gives me this
Array
(
[0] => 7
[1] => 5
[2] => 5
[3] => 5
)
then we count the array values to group dups
$rvidcounter = array_count_values($rvidarray);
which results in this
Array(
[7] => 1
[5] => 3
)
so now vender 7 as 1 low score and vendor 5 has 3 low scores and since they were already sorted by date i know that its consecutive. Well it sounds good anyway lol ")
then we create our final array with another foreach
foreach($rvidcounter as $key => $value)
{
//anything 3 or over is your watchlist
if($value > 2)
{
$watchlist[] = $key; //rvid number stored
}
}//close foreach
which gives me this
Array
(
[0] => 5
)
this was all done in a service function. So the final deal is everyone in this array has over 3 consecutive low ratings and then i just use a returned array back in my normal php process file and grab the name of each vender by id and pass that to the html and print out the list.
done...
please feel free to improve on this if you like. I may or may not use it because the above code makes sense to me. Something more complicated may not make sense to me 6 mos from now lol But it would be interesting to see what someone comes up with to shorten the process a bit.
Thanks so much and Happy Coding !!!!!
Dave :)
You could do it in SQL like that:
SET #rvid = -1;
SELECT DISTINCT rvid FROM
(
SELECT
rvid,
#neg := rating<3, /* 0 or 1 for addition in next line */
#count := IF(#rvid <> rvid , #neg, #count+#neg) AS `count`, /* set or add */
#rvid := rvid /* remember last row */
FROM
testdb.venrate
ORDER BY
rvid, datetime desc
) subq
WHERE count>=3
;
You set a variable to a non existing id. In each chronologically sorted row you check if rating is too low, that results in 1 (too low) or 0 (ok). If rvid is not equal to the last rvid, it means a new vender section is beginning. On begin of section set the value 0 or 1, else add this value. Finally store the current row's rvid for comparison in next row process.
The code above is looking for 3 consecutive low ratings (low means a value less than 3) over all the time.
A small modification checks if all the latest 3 ratings has been equal to or less than 3:
SET #rvid = -1;
SELECT DISTINCT
rvid
FROM
(
SELECT
rvid,
#high_found := rating>3 OR (#rvid = rvid AND #high_found) unflag,
#count := IF(#rvid <> rvid , 1, #count+1) AS `count`,
#rvid := rvid /* remember last row */
FROM
testdb.venrate
ORDER BY
rvid, datetime desc
) subq
WHERE count=3 AND NOT unflag
;
I’ve seen the following question on StackOverflow, Intelligent MySQL GROUP BY for Activity Streams posted by Christian Owens 12/12/12.
So I decided to try out the same approach, make two tables similar to those of his. And then I pretty much copied his query which I do understand.
This is what I get out from my sandbox:
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[action] => published_post
[object_id] => 776286559146635
[object_type] => post
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 0
)
)
I am curious, since looking at the results in Owens question, I am not able to fully get something, and does he perform additional queries to grab the actual metadata? And if yes, does this mean that one can do it from that single query or does one need to run different optimized sub-queries and then loop through the arrays of data to render the stream itself.
Thanks a lot in advanced.
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[fullname] => David Anderson
[action] => hearted
[object_id] => array (
[id] => 3438983
[title] => Grand Theft Auto
[Category] => Games
)
[object_type] => product
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 1
)
)
In "pseudo" code you need something like this
$result = $pdo->query('
SELECT stream.*,
object.*,
COUNT(stream.id) AS rows_in_group,
GROUP_CONCAT(stream.id) AS in_collection
FROM stream
INNER JOIN follows ON stream.user_id = follows.following_user
LEFT JOIN object ON stream.object_id = object.id
WHERE follows.user_id = '0'
GROUP BY stream.user_id,
stream.verb,
stream.object_id,
stream.type,
date(stream.stream_date)
ORDER BY stream.stream_date DESC
');
then parse the result and convert it in php
$data = array(); // this will store the end result
while($row = $result->fetch(PDO::FETCH_ASSOC)) {
// here for each row you get the keys and put it in a sub-array
// first copy the selected `object` data into a sub array
$row['object_data']['id'] = $row['object.id'];
$row['object_data']['title'] = $row['object.title'];
// remove the flat selected keys
unset($row['object.id']);
unset($row['object.title']);
...
$data[] = $row; // move to the desired array
}
you should get
Array
(
[0] => Array
(
[id] => 0
[user_id] => 1
[fullname] => David Anderson
[verb] => hearted
[object_data] => array (
[id] => 3438983
[title] => Grand Theft Auto
[Category] => Games
)
[type] => product
[stream_date] => 2015-11-24 12:28:09
[rows_in_group] => 1
[in_collection] => 1
)
)
It seems that you want a query where you can return the data you're actually able to get plus the user fullname and the data related to the object_id.
I think that the best effort would be to include some subqueries in your query to extract these data:
Fullname: something like (SELECT fullname FROM users WHERE id = stream.user_id) AS fullname... or some modified version using the stream.user_id, as we can't identify in your schema where this fullname comes from;
Object Data: something like (SELECT CONCAT_WS(';', id, title, category_name) FROM objects WHERE id = stream.object_id) AS object_data. Just as the fullname, we can't identify in your schema where these object data comes from, but I'm assuming it's an objects table.
One object may have just one title and may have just one category. In this case, the Object Data subquery works great. I don't think an object can have more than one title, but it's possible to have more than one category. In this case, you should GROUP_CONCAT the category names and take one of the two paths:
Replace the category_name in the CONCAT_WS for the GROUP_CONCAT of all categories names;
Select a new column categories (just a name suggestion) with the subquery which GROUP_CONCAT all categories names;
If your tables were like te first two points of my answer, a query like this may select the data, just needing a proper parse (split) in PHP:
SELECT
MAX(stream.id) as id,
stream.user_id,
(select fullname from users where id = stream.user_id) as fullname,
stream.verb,
stream.object_id,
(select concat_ws(';', id, title, category_name) from objects where id = stream.object_id) as object_data,
stream.type,
date(stream.stream_date) as stream_date,
COUNT(stream.id) AS rows_in_group,
GROUP_CONCAT(stream.id) AS in_collection
FROM stream
INNER JOIN follows ON 1=1
AND stream.user_id = follows.following_user
WHERE 1=1
AND follows.user_id = '0'
GROUP BY
stream.user_id,
stream.verb,
stream.object_id,
stream.type,
date(stream.stream_date)
ORDER BY stream.stream_date DESC;
In ANSI SQL you can't reference columns not listed in your GROUP BY, unless they're in aggregate functions. So, I included the id as an aggregation.
I'm trying to code a search function for a site written on CodeIgniter but have trouble with the join statement in the model.
A controller passes an array of search criteria to the model function: get_sales($search_criteria);
function get_sales($search_criterie){
$this->db->join('sales_prices', 'sales_prices.sale_id = sales.sale_id', 'left');
$this->db->join('sales_sizes', 'sales_sizes.sale_id = sales.sale_id', 'left');
$query = $this->db->get_where('sales', $search_criterie);
$sale_data = $query->result_array();
}
I'm running into two problems:
1) I need a WHERE clause in the sales_sizes join. Right now it joins sales_sizes.sale_id ON sales.sale_id but I want to be able to filter by size via the $search_criteria array. How can I do this?
2) Every sales usually has multiple sizes and I want the output of the query formatted like:
Array
(
[sale_id] => 1
[sale_category] => shoes
[sale_price] => 29.99
[sale_sizes] => Array
(
[0] => 10
[1] => 10.5
[2] => 11
)
)
I've tried some foreach loops to format the output but can't get it to work. Hope somebody can help.
Update:
How do I process the following query result into a format like the one above?
Array
(
[0] => Array
(
[sale_id] => 1
[sale_category] => shoes
[sale_price] => 29.99
[sale_size] => 10
)
[1] => Array
(
[sale_id] => 1
[sale_category] => shoes
[sale_price] => 29.99
[sale_size] => 10.5
)
[2] => Array
(
[sale_id] => 1
[sale_category] => shoes
[sale_price] => 29.99
[sale_size] => 11
)
)
I am personally not a big fan of using the active record as given. I find that it often restricts the programmer from writing more complex queries. If you find that this is true as well you could rewrite your query as followed:
$this->db->query('SELECT * FROM `sales_prices`, `sales_sizes` WHERE `sales_prices`.`sale_id` = `sales`.`sale_id` AND `sales_sizes`.`sale_id` = `sales`.`sale_id` AND `sales` = ?', array($search_criterie));
$sale_data = $query->results();
This will generate the same result and will also parameterize your query. Note that the question mark corresponds in order to values in your array that will make up the second parameter of you $this->db->query() function.
Try this type of query
$this->db->select('places.*, category.*')
->from('places')
->join('category', 'places.category_id = category.category_id', 'left')
->join('places_reviews', 'places_reviews.place_id = places.id', 'left')
->where('places.category_id', $category_id)
->limit($limit, $offset)
->order_by($sort_by, $sort_order);
The below solution will work for you, it won't generate exact output, but very close to one.
$this->db->select('sales.*, GROUP_CONCAT(DISTINCT sales_prices.sale_id) as sales_price GROUP_CONCAT(DISTINCT sales_sizes.sale_id) as sales_size')
This will generate a comma separated value for you.
This is essentially very simple I've just been rather verbose about it. My data is structured as shown at the bottom of my post. My goal is to organise the data in a simple spreadsheet format, 'flattening' the relational database. Something like:
Product1 URL
Product2 URL URL URL
Product3 URL
My initial approach is as below. The reason I'm looking for an alternative is I have > 10,000 rows in the products table and each product has an average of 5 URLs. This generates an enourmous amount of MySQL queries (in fact exceeding my shared hosting resources), there must be a better way, right? My code has been simplified to distill the essence of my question.
My Approach
//Query to get all products
$products = mysql_query("SELECT * FROM products");
$i = 0;
//Iterate through all products
while($product = mysql_fetch_array($products)){
$prods[$i]['name'] = $product['name'];
$prods[$i]['id'] = $product['id'];
//Query to get all URLs associated with this particular product
$getUrls = mysql_query("SELECT * FROM urls WHERE product_id =".$product['id']);
$n = 0;
while($url = mysql_fetch_array($getUrls)){
$prods[$i]['urls'][$n] = $url['url'];
}
}
The Result
To be clear, this is the intended result, the output was expected. I just need a more efficient way of getting from the raw database tables to this multidimensional array. I suspect there's more efficient ways of querying the database. Also, I understand that this array uses a lot of memory when scaled up to the required size. As my aim is to use this array to export the data to .csv I would consider using XML (or something) as an intermediary if it is more efficient. So feel free to suggest a different approach entirely.
//The result from print_r($prods);
Array
(
[0] => Array
(
[name] => Swarovski Bracelet
[id] => 1
[urls] => Array
(
[0] => http://foo-example-url.com/index.php?id=7327
)
)
[1] => Array
(
[name] => The Stranger - Albert Camus
[id] => 2
[urls] => Array
(
[0] => http://bar-example-url.com/index.php?id=9827
[1] => http://foo-foo-example-url.com/index.php?id=2317
[2] => http://baz-example-url.com/index.php?id=5644
)
)
)
My Database Schema
Products
id product_name
1 Swarovski Bracelet
2 The Stranger - Albert Camus
3 Finnegans Wake - James Joyce
URLs
id product_id url price
1 1 http://foo-example-url.com/index.php?id=7327 £16.95
2 2 http://bar-example-url.com/index.php?id=9827 £7.95
3 2 http://foo-foo-example-url.com/index.php?id=2317 £7.99
4 2 http://baz-example-url.com/index.php?id=5644 £6.00
5 3 http://bar-baz-example-url.com/index.php?id=9534 £11.50
URLs.product_id links to products.id
If you've read this, thank you for your incredible patience! I look forward to reading your response. So how can I do this properly?
The SQL
SELECT p.id, p.product_name, u.url
FROM products p, urls u
WHERE p.id = u.product_id ORDER BY p.id
PHP code to "flatten" the urls, I have just seperated the urls with a space.
$i = 0;
$curr_id;
while($product = mysql_fetch_array($products))
{
$prods[$i]['name'] = $product['product_name'];
$prods[$i]['id'] = $product['id'];
if($product['id'] == $curr_id)
{
$prods[$i]['urls'] .= " ".$url['url'];
}
else
{
$prods[$i]['urls'] = $url['url'];
}
$i++;
$curr_id = $product['id'];
}
The Result
[0] => Array
(
[name] => Swarovski Bracelet
[id] => 1
[urls] => http://foo-example-url.com/index.php?id=7327
)
[1] => Array
(
[name] => The Stranger - Albert Camus
[id] => 2
[urls] => http://bar-example-url.com/index.php?id=9827 http://foo-foo-example-url.com/index.php?id=2317 http://baz-example-url.com/index.php?id=5644
)
You are able to pull back that exact information with one query even if you want to pull back the csv of urls.
SELECT
p.id, p.product_name,
GROUP_CONCAT(u.url) AS URLS
FROM products p LEFT JOIN urls u
ON p.id = u.product_id
GROUP BY p.id, p.product_name
And then you have 1 query to your database that brings back what you need.
Or the cleaner approach is how bruce suggested and then let PHP merge all of the results together.
You can accomplish this in one query:
select * from products join urls on products.id = urls.product_id order by products.id
pseudocode:
while(query_result) {
if (oldpid == pid) { print ", \"url\"" }
else { print "pid, \"url\"" }
oldpid = pid;
}