I'm sure I have done something like this before, but can't find it and google not being helpful.
Using Phalcon model if possible, I want to select the items from a table whose ID appears the most - i.e. 10 most popular items ordered by popularity. Is this possible using Model::find("conditions")? I do I have to use PHQL for this?
using model::find
Model::find([
'columns' => 'id,count(id) as counter',
'group' => 'id',
'order' => 'counter DESC'
]);
PHQL:
$this->modelsManager->executeQuery('SELECT count(id) AS counter,id FROM ModelName GROUP BY id ORDER BY counter DESC');
find() does have a group clause, but I don't think it's possible to do what you want because you also need to do a count.
Talal's answer is close, but won't work if you want a list of model objects.
Something like this should work:
$Results = $this->modelsManager->executeQuery('SELECT * FROM ModelName GROUP BY id ORDER BY count(id) DESC LIMIT 10');
$Results->setHydrationMode(\Phalcon\Mvc\Model\Resultset::HYDRATE_RECORDS);
Setting the hydration mode may not be necessary, as Phalcon may default to that mode based on the fact the query is asking for *.
Related
I'm trying to set up a subquery in ZendFramework 2 and I got an issue with the limit function for a Select object. Whatever I do, numeric value is put between quotes and makes my query fails : I should get LIMIT 1 and instead I get LIMIT '1'.
Seems this is not the first time this issue has been encountered, I saw some have asked about this issue before (like 8 months ago) but without getting any proper answer.
I also saw this issue has been marker as resolved in 2012 (https://github.com/zendframework/zf2/pull/2775) so I really don't understand what's happening there.
Here's my code in ZF2 :
$resultSet = $this->tableGateway->select( function (Select $select) use ($params) {
$sub = new Select();
$sub->from(array('temp' => 'scores'))
->columns(array(new \Zend\Db\Sql\Expression("id AS id")))
->where(array('temp.glitch' => array('None', 'Glitch')))
->where('temp.zone=scores.zone')
->order('temp.multi DESC, temp.score DESC')
->limit(1);
$select->join('players', 'player=players.id', array('player_name' => 'name', 'player_url' => 'name_url'))
->join('countries', 'players.country=countries.id', array('country_name' => 'name', 'country_iso' => 'iso'))
->join('cars', 'car=cars.id', array('car_name' => 'name'), 'left')
->join('zones', 'zone=zones.id', array('zone_name' => 'name'));
$select->where(array('scores.id' => $sub));
$select->order('scores.zone ASC');
print_r($select->getSqlString());
});
This should render the following query (which I get right except LIMIT '1' instead of LIMIT 1) :
SELECT "scores".*, "players"."name" AS "player_name", "players"."name_url" AS "player_url", "countries"."name" AS "country_name", "countries"."iso" AS "country_iso", "cars"."name" AS "car_name", "zones"."name" AS "zone_name"
FROM "scores" INNER JOIN "players" ON "player"="players"."id"
INNER JOIN "countries" ON "players"."country"="countries"."id"
LEFT JOIN "cars" ON "car"="cars"."id"
INNER JOIN "zones" ON "zone"="zones"."id"
WHERE "scores"."id" = (SELECT id AS id FROM "scores" AS "temp" WHERE "temp"."glitch" IN ('None', 'Glitch')
AND temp.zone=scores.zone ORDER BY "temp"."multi" DESC, "temp"."score" DESC LIMIT 1)
ORDER BY "scores"."zone" ASC
Since this doesn't seem to work this way, is there another way I could proceed to get my limit (using Mysql 5 database) ?
EDIT :
Thanks for your help. Finally I figured out a way to get things done the way I want and to remove the quotes by simply remove the subquery construction and to write it directly in the where function :
$select->where('scores.id = (SELECT id FROM scores AS lookup WHERE lookup.zone = scores.zone ORDER BY multi DESC , score DESC LIMIT 1)');
Although I can continue my dev with this, I feel more like using a poor trick to get rid of this issue and so I will let this question unanswered until someone comes with a real solution there.
Anyway there might be no solution at all, since it might be an issue in ZF2 core itself.
Change the line -
$select->where(array('scores.id' => $sub));
with
$select->where(array('scores.id' => new \Zend\Db\Sql\Expression("({$sub->getSqlString($this->tableGateway->adapter->getPlatform())})"));
Try with just above change.
And if it still doesn't work then make changes to the core Select class file located at -
PROJECT_FOLDER/vendor/zendframework/zendframework/library/Zend/Db/Sql/Select.php
Line No. 921 -
Change $sql = $platform->quoteValue($limit); with $sql = $limit;
Line No. 940 -
Change return array($platform->quoteValue($offset)); with return array($offset);
I have come across the issue from github and wondered as why it is still not working with the latest ZF2 files. I know the solution given above doesn't look like the proper one but I had to somehow make it work. I have tried it and it works.
Its only a quick fix before the actual solution comes into picture.
I'm writing a SQL query to order products by price asc, but putting products with 0 price at last.
As I know, I can use ORDER BY IF(price=0,1,0) ASC, price ASC to get it done. But when I pass 'order' => array('IF(Product.price=0, 1, 0) ASC', 'Product.price' => 'ASC') to the paginate component in CakePHP, the IF part is dismissed automatically.
I'm wondering how to get it done in CakePHP with CakePHP style param array?
i think you want this...
if($condition) ? /**want do you want if true/ : /** do what you want if false/;
hope it help
I'm working on developing a category roll-up report for a Magento (1.6) store.
To that end, I want to get an Order Item collection for a subset of products - those product whose unique category id (that's a Magento product attribute that I created) match a particular value.
I can get the relevant result set by basing the collection on catalog/product.
$collection = Mage::getModel('catalog/product')
->getCollection()
->addAttributeToFilter('unique_category_id', '75')
->joinTable('sales/order_item', 'product_id=entity_id', array('price'=>'price','qty_ordered' => 'qty_ordered'));
Magento doesn't like it, since there are duplicate entries for the same product id.
How do I craft the code to get this result set based on Order Items? Joining in the product collection filtered by an attribute is eluding me. This code isn't doing the trick, since it assumes that attribute is on the Order Item, and not the Product.
$collection = Mage::getModel('sales/order_item')
->getCollection()
->join('catalog/product', 'entity_id=product_id')
->addAttributeToFilter('unique_category_id', '75');
Any help is appreciated.
The only way to make cross entity selects work cleanly and efficiently is by building the SQL with the collections select object.
$attributeCode = 'unique_category_id';
$alias = $attributeCode.'_table';
$attribute = Mage::getSingleton('eav/config')
->getAttribute(Mage_Catalog_Model_Product::ENTITY, $attributeCode);
$collection = Mage::getResourceModel('sales/order_item_collection');
$select = $collection->getSelect()->join(
array($alias => $attribute->getBackendTable()),
"main_table.product_id = $alias.entity_id AND $alias.attribute_id={$attribute->getId()}",
array($attributeCode => 'value')
)
->where("$alias.value=?", 75);
This works quite well for me. I tend to skip going the full way of joining the eav_entity_type table, then eav_attribute, then the value table etc for performance reasons. Since the attribute_id is entity specific, that is all that is needed.
Depending on the scope of your attribute you might need to add in the store id, too.
I have a voting system with two models: Item(id, name) and Vote(id, item_id, user_id).
Here's the code I have so far:
class Item < ActiveRecord::Base
has_many :votes
def self.most_popular
items = Item.all #where can I optimize here?
items.sort {|x,y| x.votes.length <=> y.votes.length}.first #so I don't need to do anything here?
end
end
There's a few things wrong with this, mainly that I retrieve all the Item records, THEN use Ruby to compute popularity. I am almost certain there is a simple solution to this, but I can't quite put my finger on it.
I'd much rather gather records and run the calculations in the initial query. This way, I can add a simple :limit => 1 (or LIMIT 1) to the query.
Any help would be great--either rewrite in all ActiveRecord or even in raw SQl. The latter would actually give me a much clearer picture of the nature of the query I want to execute.
Group the votes by item id, order them by count and then take the item of the first one. In rails 3 the code for this is:
Vote.group(:item_id).order("count(*) DESC").first.item
In rails 2, this should work:
Vote.all(:order => "count(*) DESC", :group => :item_id).first.item
sepp2k has the right idea. In case you're not using Rails 3, the equivalent is:
Vote.first(:group => :item_id, :order => "count(*) DESC", :include => :item).item
Probably there's a better way to do this in ruby, but in SQL (mysql at least) you could try something like this to get a top 10 ranking:
SELECT i.id, i.name, COUNT( v.id ) AS total_votes
FROM Item i
LEFT JOIN Vote v ON ( i.id = v.item_id )
GROUP BY i.id
ORDER BY total_votes DESC
LIMIT 10
One easy way of handling this is to add a vote count field to the Item, and update that each time there is a vote. Rails used to do that automatically for you, but not sure if it's still the case in 2.x and 3.0. It's easy enough for you to do it in any case using an Observer pattern or else just by putting in a "after_save" in the Vote model.
Then your query is very easy, by simply adding a "VOTE_COUNT DESC" order to your query.
ActiveRecord objects of the class 'Location' (representing the db-table Locations) have the attributes 'url', 'lat' (latitude) and 'lng' (longitude).
Lat-lng-combinations on this model should be unique. The problem is, that there are a lot of Location-objects in the database having duplicate lat-lng-combinations.
I need help in doing the following
Find objects that share the same
lat-lng-combination.
If the 'url' attribute of the object
isn't empty, keep this object and delete the
other duplicates. Otherwise just choose the
oldest object (by checking the attribute
'created_at') and delete the other duplicates.
As this is a one-time-operation, solutions in SQL (MySQL 5.1 compatible) are welcome too.
If it's a one time thing then I'd just do it in Ruby and not worry too much about efficiency. I haven't tested this thoroughly, check the sorting and such to make sure it'll do exactly what you want before running this on your db :)
keep = []
locations = Location.find(:all)
locations.each do |loc|
# get all Locations's with the same coords as this one
same_coords = locations.select { |l| l.lat == loc.lat and \
l.lng == loc.lng }
with_urls = same_coords.select { |l| !l.url.empty? }
# decide which list to use depending if there were any urls
same_coords = with_urls.any? ? with_urls : same_coords
# pick the best one
keep << same_coords.sort { |a,b| b.created_at <=> a.created_at }.first.id
end
# only keep unique ids
keep.uniq!
# now we just delete all the rows we didn't decide to keep
locations.each do |loc|
loc.destroy unless keep.include?( loc.id )
end
Now like I said, this is definitely poor, poor code. But sometimes just hacking out the thing that works is worth the time saved in thinking up something 'better', especially if it's just a one-off.
If you have 2 MySQL columns, you can use the CONCAT function.
SELECT * FROM table1 GROUP BY CONCAT(column_lat, column_lng)
If you need to know the total
SELECT COUNT(*) AS total FROM table1 GROUP BY CONCAT(column_lat, column_lng)
Or, you can combine both
SELECT COUNT(*) AS total, table1.* FROM table1
GROUP BY CONCAT(column_lat, column_lng)
But if you can explain more on your question, perhaps we can have more relevant answers.