In eloquent, how can I skip 10 rows and then get the rest of the table?
User::skip(10)->all();
The above does not work, but it gives you an idea what I am looking for.
Try this:
$count = User::count();
$skip = 10;
User::skip($skip)->take($count - $skip)->get();
With one query:
User::skip($skip)->take(18446744073709551615)->get();
It's ugly, but it's an example from official MySQL manual:
To retrieve all rows from a certain offset up to the end of the result
set, you can use some large number for the second parameter. This
statement retrieves all rows from the 96th row to the last:
SELECT * FROM tbl LIMIT 95,18446744073709551615;
try something like this it work for sure..
$temp = User::count();
$count = $temp - 10;
$data = User::take($count)->skip(10)->get();
Laravel 5 returns Eloquent result as Collection.
So you can use collenction function slice();
$users = User::get();
$slicedUsers = $users->slice(10);
Related
I use Laravel 6.12, I have this request :
$queryJob = DB::table('jobs as j')->join('job_translations as jt', 'j.id', 'jt.job_id')
->whereNull('j.deleted_at')
->whereNull('jt.deleted_at')
->select('j.id', 'j.short_name', 'j.status', DB::raw("case when j.short_name = '{$request->short_name}' then 0 else 1 end"))
->distinct();
$jobs = $queryJob->paginate($qtyItemsPerPage);
The results displays an error for the total :
The total = 3, but as you can see the data contains only 2 elements.
I read here that when using a distinct, I must be clear on which column the total must be calculated: distinct() with pagination() in laravel 5.2 not working
So I modified my query like that:
$jobs = $queryJob->paginate($qtyItemsPerPage, ['j.*']);
But without success, the total is still wrong.
Hoping that I don't misunderstand your DB and relations structure and purpose of your query perhaps this will avoid using distinct or groupBy altogether?
$shortname = $request->input('short_name');
$queryJob = Job::with('job_translations')->select('id','short_name',
'status', DB::raw("case when short_name = '" . $shortname . "'
then 0 else 1 end")
->paginate($qtyItemsPerPage);
Pagination can be easily manually added with skip and take in case you need to use groupBy
$queryJob->skip(($page - 1) * $qtyItemsPerPage)->take($qtyItemsPerPage)->get();
The solution for me was to pass a field name to the distinct() method.
With your example:
$queryJob = DB::table('jobs as j')
// joins, where and other chained methods go here
->distinct('j.id')
Solution taken from https://stackoverflow.com/a/69073801/3503615
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();
If I have a query like:
$posts = Post::all();
How can I select the first 5 results from that previous query? I tried the following, but it didn't work:
$first_five = $posts->take(5)->get();
Or in other words, how do I get the first 5 elements in the returned object?
I know you can use $first_five = Post::all()->take(5)->get();
I am guessing you may be able to do this also:
$posts = Post::all();
$first_five = $posts->take(5);
Also, have a look into pagination.
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();
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/