i am little bit confused that how my query convert in laravel..
select users.username,users.photo, questions.*,
(Select count(*) from answers
where answers.q_id=questions.id) as aAccount from questions
INNER JOIN users ON users.id=questions.user_id
Use Raw query
These expressions will be injected into the query as strings, so be careful not to create any SQL injection points! To create a raw expression, you may use the DB::raw method
DB::table('questions')
->join('users', 'users.id', '=', 'questions.user_id')
->select('users.username','users.photo', 'questions.*',
DB::raw("
( Select count(*) from answers
where answers.q_id=questions.id
)as 'aAccount'")
->get();
I upvoted JYoThl answer as it's exactly how I'd breakdown this query into eloquent, though in instances where a portion of your Eloquent query becomes raw, I personally prefer keeping the entire sql raw. You can still inject variables into it if required.
In my experience, the amount of time spent normalizing a more complex query like this will be used when you go back to the code to re-read it.
Here's how you would pass your sql in it's raw format. I also like to convert the array into a collection, as collections offer a variety of methods. Hope this helps!
$questions = collect(DB::select( DB::raw("
select users.username,users.photo, questions.*,
(Select count(*) from answers where answers.q_id=questions.id) as aAccount
from questions
INNER JOIN users ON users.id=questions.user_id")
));
You would add variables into an array() area if you want to inject a variable. If you wanted to do that you would do something like this:
DB::select( DB::raw("select * from user where user = :user"), array('user' => $user))
Related
I have two tables.
rooms with id, title
chats with id, content, room_id, created_at
My goal is fetch rooms and orderBy created_at of chats in desc mode. It's a simple query, yet it's giving a headache in Laravel. I cannot use the eloquent ORM way and do a sort in with method. Thus, I had to use a join.
My query looks like this:
$items = $items->select("rooms.*")->join("chats", "chats.room_id", "=", "rooms.id")->orderBy("chats.created_at", "desc")->groupBy('rooms.id');
Result:
I'm getting the data without any order for created_at.
removing groupBy will result in a correct order, but because it's missing the groupby, the room will exist as much as it has chats. So it's not a great approach.
What am I missing? If i need to include other information, please let me know in the comments.
Just like the comment said, I should use an aggregate function in the query while using a groupby function. Basically, it will look like this
$items = $items->select("rooms.*")
->selectRaw("max(chats.created_at) as latest_created_at")
->join("chats", "chats.room_id", "=", "rooms.id")
->orderBy("latest_created_at", "desc")
->groupBy('rooms.id');
Then, it will be ordered correctly. I'll leave the thread, maybe someone will use the same clumsy search keywords as mine and see this question :)
I have a Question model from very large table of questions (600,000 records), with relation to Customer,Answer and Product models. Relations are irrelevant to this question but I mentioned them to clarify I need to use Eloquent. When I call Question::with('customer')->get(); it runs smoothly and fast.
But there is another table in which I have question_ids of all questions which should not be shown (for specific reasons).
I tried this code:
// omitted product ids, about 95,000 records
$question_ids_in_product = DB::table('question_to_product')
->pluck('product_id')->all();
$questions = Question::with('customer')
->whereNotIn('product_id', $question_ids_in_product)
->paginate($perPage)->get();
It takes so much time and shows this error:
SQLSTATE[HY000]: General error: 1390 Prepared statement contains too many placeholders
and sometimes Fatal error: Maximum execution time of 30 seconds exceeded
When I run it with plain sql query:
SELECT * FROM questions LEFT JOIN customers USING (customer_id)
WHERE question_id NOT IN (SELECT question_id FROM question_to_product)
it takes only 80 milliseconds
How can I use Eloquent in this situation?
You can use whereRaw method:
$questions = Question::with('customer')
->whereRaw('question_id NOT IN (SELECT question_id FROM question_to_product)')
->paginate($perPage)->get();
But ideally as you found out this is a better sollution:
Question::with('customer')->whereNotIn('question_id',
function ($query) {
$query->from('question_to_product') ->select('question_id');
}
);
Difference?
When you will migrate your database to another database the whereRaw might not work as you put in raw statements.
That is why we have Eloquent ORM which handles these transitions and build the appropriate queries to run.
No performance impact because the SQL is the same (for MySQL)
P.S: For better debugging try installing this debug bar
refer from https://laravel.com/docs/5.4/queries#where-clauses
$users = DB::table('questions')
->leftJoin('customers', 'curtomer.id', '=', 'question.user_id')
->whereNotIn('question_id', [1, 2, 3])
->get();
It'll work 100%. When you query getting longer to response like more than 30 seconds when you are using whereNotIn. Use this Query Syntax.
$order = Order::on($databaseCredentials['database'])
->whereRaw('orders_id NOT IN (SELECT orders_id FROM orders)')
->skip($page)
->take(10)
->orderBy('orders.updated_at', 'ASC')
->paginate(10);
Hello i'm new to laravel framework
i have a MySQL query .This work perfectly fine.
select sample.name, ABS((COALESCE(sample.openingbalance, 0)) + COALESCE(trs.TotalAmount, 0)) from sample left join (select ledger,sum(amount) AS TotalAmount from transaction group by transaction.ledger) AS trs on sample.name = trs.ledger
I want to write this query so that it is executed in laravel framework
i tried the following query but its not working
DB::table('sample')->select('sample.name',abs((COALESCE('sample.openingbalance',0))+COALESCE('trs.totalamount',0)))->leftjoin('transaction','sample.name','=','transaction.ledger')->select('ledger','sum(amount) as totalamount')->groupBy('transaction.ledger as trs') ->get();
i think what you need is this.
Raw Expressions
Sometimes you may need to use a raw expression in a query. These expressions will be injected into the query as strings, so be careful not to create any SQL injection points! To create a raw expression, you may use the DB::raw method:
sample code
$users = DB::table('users')
->select(DB::raw('count(*) as user_count, status'))
->where('status', '<>', 1)
->groupBy('status')
->get();
for more info please refer http://laravel.com/docs/5.1/queries#selects
i'm having an issue with how eloquent is formulation a query that i have no access to. When doing something like
$model->where('something')
->distinct()
->paginate();
eloquent runs a query to get the total count, and the query looks something like
select count(*) as aggregate from .....
The problem is that if you use distinct in the query, you want something like
select count(distinct id) as aggregate from .....
to get the correct total. Eloquent is not doing that though, thus returning wrong totals. The only way to get the distinct in count is to pass an argument through the query builder like so ->count('id') in which case it will add it. Problem is that this query is auto-generated and i have no control over it.
Is there a way to trick it into adding the distinct on the count query?
P.S Digging deep into the builders code we find an IF statement asking for a field on the count() method in order to add the distinct property to the count. Illuminate\Database\Query\Grammars\BaseGrammar#compileAggregate
if ($query->distinct && $column !== '*')
{
$column = 'distinct '.$column;
}
return 'select '.$aggregate['function'].'('.$column.') as aggregate';
P.S.1 I know that in SQL you could do a group by, but since i'm eager loading stuff it is not a good idea cause it will add a IN (number of id's found) to each of the other queries which slows things down significantly.
I faced the exact same problem and found two solutions:
The bad one:
$results = $model->groupBy('foo.id')->paginate();
It works but it will costs too much memory (and time) if you have a high number of rows (it was my case).
The better one:
$ids = $model->distinct()->pluck('foo.id');
$results = $query = $model->whereIn('foo.id', $ids)->paginate();
I tried this with 100k results, and had no problem at all.
This seems to be a wider problem, discussed here:
https://github.com/laravel/framework/issues/3191
https://github.com/laravel/framework/pull/4088
Untill the fixes are shipped with one of the next Laravel releases, you can always try using the raw expressions, like below (I didnt test it, but should work)
$stuff = $model->select(DB::raw('distinct id as did'))
->where('whatever','=','whateverelse')
->paginate();
Reference: http://laravel.com/docs/queries#raw-expressions
$model->where('something')->distinct()->count('id')->paginate();
So, I need to search a real estate database for all homes belonging to realtors who are part of the same real estate agency as the current realtor. I'm currently doing this something like this:
$agency_data = $this->Realtor->find('all',array(
'conditions'=>
array(business_name'=>$realtor_settings['Realtor']['business_name']),
'fields'=>array('num'),
'recursive'=> -1
));
foreach($agency_data as $k=>$v){
foreach($v as $k=>$v1){
$agency_nums[] = $v1['num'];
}
}
$conditions = array(
'realtor_num'=>$agency_nums
);
It seems a bit crazy to me that I'm having to work so hard to break down the results of my first query, just to get a simple, one-dimensional array of ids that I can use to build a condition for my subsequent query. Am I doing this in an insanely roundabout way? Is there an easy way to write a single CakePHP query to communicate "select * from homes where realtor_num in (select num from realtors where business_name = 'n')"? If so, would it be any more efficient?
For sure it's complicated (in your way) :)
Depending from the results you can do following:
$agency_data = $this->Realtor->find('list',array(
'conditions'=>array('business_name'=>$realtor_settings['Realtor']['business_name']),
'fields'=>array('num', 'num'),
'recursive'=> -1
));
$agency_data; //this already contain array of id's
Method 2 - building a sub query there are 2 ways strict and not so strict :) The first one you can see here (search for Sub-queries).
The other option is to have following conditions parameter:
$this->Realtor->find('all', array('conditions'=>array('field in (select num from realtors where business_name like "'.$some_variable.'"))));
Of course be careful with the $some_variable in the sub-query. You shold escape it - use Sanitize class for example.
$agency_data = $this->Realtor->find('all',array(
'conditions'=>
array('business_name'=>$realtor_settings['Realtor']['business_name']),
'fields'=>array('num'),
'recursive'=> -1
));
$conditions = Set::extract("{n}.Realtor.num", $agency_data);
I would use something like Set::extract to grab the list of data you are looking for. The advantage of doing it this way is that you can reuse the same dataset in other places and save queries. You could also write the set::extract statement in this format:
$conditions = Set::extract("/Realtor/num", $agency_data);