Reusing query with one less join in codeigniter? - codeigniter

Is there any smart way of reusing current query. I want to use same query EXCEPT from one join. See example below:
$this->db->distinct();
$this->db->select('outfit_main.*');
$this->db->join('outfit_products', 'outfit_main.id = outfit_products.outfit_id');
$this->db->join('product', 'outfit_products.product_id = product.id');
$this->db->join('favorite', 'favorite.product_id = outfit_products.product_id');
$check = $this->db->get('outfit_main')->result('OutfitModel');
if ($check === false) {
//How to - use above query
//EXCEPT from
//$this->db->join('favorite', 'favorite.product_id = outfit_products.product_id');
$check = $this->db->get('outfit_main')->result('OutfitModel');
}
With smart way I mean that I wouldn't have to reset whole query and create a whole new query.

Related

Laravel Query Builder use multiple times

Is it possible to save a query bulider and use it multiple times?
for example, I have a model 'Tour'.
I create a long query buider and paginate it:
$tour = Tour::where(...)->orWhere(...)->orderBy(...)->paginate(10);
For example, 97 models qualify for the above query.
"Paginate" method outputs first 10 models qualifying for the query, but I also need to so some operations on all 97 models.
I don't want to 'repeat myself' writing this long query 2 times.
So I want something like:
$query = Tour::where(...)->orWhere(...)->orderBy(...);
$tour1 = $query->paginate(10);
$tour2 = $query->get();
Is that a correct way to do in Laravel? (my version is 5.4).
You need to use clone:
$query = Tour::where(...)->orWhere(...)->orderBy(...);
$query1 = clone $query;
$query2 = clone $query;
$tour1 = $query1->paginate(10);
$tour2 = $query2->get();
You can but it doesn't make any sense because every time a new query will be executed. So this code will work:
$query = Tour::where(...)->orWhere(...)->orderBy(...);
$tour1 = $query->paginate(10);
$tour2 = $query->get();
But if you want to execute just one query, you'll need to use collection methods for ordering, filtering and mapping the data. You'll also need to create Paginator instance manually:
$collection = Tour::where(...)->orWhere(...)->orderBy(...)->get();
$tour1 = // Make Paginator manually.
$tour2 = $collection;
$sortedByName = $collection->sortBy('name');
$activeTours = $collection->where('active', 1);

Eloquent to count with different status

It's possible to make one query to get total, sold & unsold in laravel eloquent?
$total_apple = Item::whereName('Apple')->count();
$sold_apple = Item::whereName('Apple')->whereStatus(2)->count();
$unsold_apple = Item::whereName('Apple')->whereStatus(1)->count();
Yes you can totally do that. You can use filter method on collection object returned by your Eloquent query.
$apples = Item::whereName('Apple')->get();
$soldApples = $apples->filter(function ($apple){
return $apple->status == 2;
});
$unsoldApples = $apples->filter(function ($apple){
return $apple->status == 1;
});
$soldApples and $unsoldApples contains the object of the items. You can then just use count($soldApples) and count($unsoldApples) to get their count.
filter method is against the collection object so there is no sql overhead.
There is no need run multiple queries or even fetch the entire results and use collection methods to loop through. Just use raw queries.
$apples = Item::whereName('Apple')
->selectRaw('COUNT(*) as total_apples,
SUM(status=2) as sold_apples,
SUM(status=1) as unsold_apples')
->first();
echo $apples->total_apples; // Outputs total apples
echo $apples->unsold_apples; // Outputs the unsold apples
echo $apples->sold_apples; // Outputs the sold apples
Since you are only doing simple counts though, you can use the query builder as well.
I would get all the items in one collection, then run the where statement on that collection. This should trigger a single Query.
$apples = Item::whereName('Apple')->get(); // This goes against SQL
$total_apple = $apples->count(); //This runs on the Collection object not SQL
$sold_apple = $apples->whereStatus(2)->count();
$unsold_apple = $apples->whereStatus(1)->count();

How to skip a row with file exists condition in laravel

This is for a search query based on many input fields, i'm doing if statements inside the query based on the inputs, for example :
$query = Model::all();
if($field = Input::get('field'))
$query->where('column_name', $field);
but what i want to do also is a condition to skip a row if there is no image with a name of that row id, like so :
if( file_exists('/img/'.$this_query->id) )
$query->skip();
Option 1: would be to make an array of the filenames, then utilize the whereIn query builder method, which checks for the occurrence of a column value in an array.
$query = Model::query();
$filenames = scandir('/img');
// the following excludes any id's not in the $filenames array
$query = $query->whereIn('id', $filenames);
Option 2: Run the query and then filter the resulting Collection in Laravel.
$query = Model::query();
// ... then build up your query
// the following gets the query results and then filters them out
$collection = $query->get()->filter( function($item) {
return file_exists('/img/'.$item->id);
}
Rationale: the database cannot check the filesystem during it's processing; so you either need to (Option 1) provide it a list from which to check, or (Option 2) do the checking after you get() the results back from the query.

Laravel query optimization

I have a query in laravel:
...
$query = $model::group_by($model->table().'.'.$model::$key);
$selects = array(DB::raw($model->table().'.'.$model::$key));
...
$rows = $query->distinct()->get($selects);
this works fine and gives me the fields keys' that I need but the problem is that I need to get all the columns and not just the Key.
using this:
$selects = array(DB::raw($model->table().'.'.$model::$key), DB::raw($model->table().'.*'));
is not an option, cuz it's not working with PostgreSQL, so i used $rows to get the rest of columns:
for ($i = 0; $i<count($rows); $i++)
{
$rows[$i] = $model::find($rows[$i]->key);
}
but as you see this is it's so inefficient, so what can i do to make it faster and more efficient?
you can find the whole code here: https://gist.github.com/neo13/5390091
ps. I whould use join but I don't know how?
Just don't pass anything in to get() and it will return all the columns. Also the key is presumably unique in the table so I don't exactly understand why you need to do the group by.
$models = $model::group_by( $model->table() . '.'. $model::$key )->get();

Codeigniter Pagination: Run the Query Twice?

I'm using codeigniter and the pagination class. This is such a basic question, but I need to make sure I'm not missing something. In order to get the config items necessary to paginate results getting them from a MySQL database it's basically necessary to run the query twice is that right?
In other words, you have to run the query to determine the total number of records before you can paginate. So I'm doing it like:
Do this query to get number of results
$this->db->where('something', $something);
$query = $this->db->get('the_table_name');
$num_rows = $query->num_rows();
Then I'll have to do it again to get the results with the limit and offset. Something like:
$this->db->where('something', $something);
$this->db->limit($limit, $offset);
$query = $this->db->get('the_table_name');
if($query->num_rows()){
foreach($query->result_array() as $row){
## get the results here
}
}
I just wonder if I'm actually doing this right in that the query always needs to be run twice? The queries I'm using are much more complex than what is shown above.
Unfortunately, in order to paginate you must know how many elements you are breaking up into pages.
You could always cache the result for the total number of elements if it is too computationally expensive.
Yeah, you have to run two queries, but $this->db->count_all('table_name'); is one & line much cleaner.
Pagination requires reading a record set twice:
Once to read the whole set so that it can count the total number records
Then to read a window of records to display
Here's an example I used for a project. The 'banner' table has a list of banners, which I want to show on a paginated screen:
Using a public class property to store the total records (public $total_records)
Using a private function to build the query (that is common for both activities). The parameter ($isCount) we pass to this function reduces the amount of data the query generate, because for the row count we only need one field but when we read the data window we need all required fields.
The get_list() function first calls the database to find the total and stores it in $total_records and then reads a data window to return to the caller.
Remember we cannot access $total_records without first calling the get_list() method !
class Banner_model extends CI_Model {
public $total_records; //holds total records for get_list()
public function get_list($count = 10, $start = 0) {
$this->build_query();
$query = $this->db->get();
$result = $query->result();
$this->total_records = count($result); //store the count
$this->build_query();
$this->db->limit($count, $start);
$query = $this->db->get();
$result = $query->result();
return $result;
}
private function build_query($isCount = FALSE) {
$this->db->select('*, b.id as banner_id, b.status as banner_status');
if ($isCount) {
$this->db->select('b.id');
}
$this->db->from('banner b');
$this->db->join('company c', 'c.id = b.company_id');
$this->db->order_by("b.id", "desc"); //latest ones first
}
And now from the controller we call:
$data['banner_list'] = $this->banner_model->get_list();
$config['total_rows'] = $this->banner_model->total_records;
Things get complicated when you start using JOINs, like in my example where you want to show banners from a particular company! You may read my blog post on this issue further:
http://www.azmeer.info/pagination-hitting-the-database-twise/

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