Get the Query Executed in Laravel 3/4

Question 1

How can I retrieve the raw executed SQL query in Laravel 3/4 using Laravel Query Builder or Eloquent ORM?

For example, something like this:

DB::table('users')->where_status(1)->get();

Or:

(posts (id, user_id, ...))

User::find(1)->posts->get();

Otherwise, at the very least how can I save all queries executed to laravel.log?

Question 2

Laravel 4+

In Laravel 4 and later, you have to call DB::getQueryLog() to get all ran queries.

$queries = DB::getQueryLog();
$last_query = end($queries);

Or you can download a profiler package. I'd recommend barryvdh/laravel-debugbar, which is pretty neat. You can read for instructions on how to install in their repository.

Note for Laravel 5 users: You'll need to call DB::enableQueryLog() before executing the query. Either just above the line that runs the query or inside a middleware.

Laravel 3

In Laravel 3, you can get the last executed query from an Eloquent model calling the static method last_query on the DB class.

DB::last_query();

This, however, requires that you enable the profiler option in application/config/database.php. Alternatively you could, as @dualed mentioned, enable the profiler option, in application/config/application.php or call DB::profile() to get all queries ran in the current request and their execution time.

Question 3

Well I found the solution. It can be done one by passing a closure function in with() as second index of array like

Post::query()
    ->with(array('user' => function($query) {
        $query->select('id','username');
    }))
    ->get();

It will only select id and username from other table. I hope this will help others.

Remember that the primary key (id in this case) needs to be the first param in the $query->select() to actually retrieve the necessary results.*

Question 4

By default, the query log is disabled in Laravel 5: https://github.com/laravel/framework/commit/e0abfe5c49d225567cb4dfd56df9ef05cc297448

You will need to enable the query log by calling:

DB::enableQueryLog();

// and then you can get query log

dd(DB::getQueryLog());

or register an event listener:

DB::listen(
    function ($sql, $bindings, $time) {
        //  $sql - select * from `ncv_users` where `ncv_users`.`id` = ? limit 1
        //  $bindings - [5]
        //  $time(in milliseconds) - 0.38 
    }
);

Some Tips

1. Multiple DB connections

If you have more than one DB connection you must specify which connection to log

To enables query log for my_connection:

DB::connection('my_connection')->enableQueryLog();

To get query log for my_connection:

print_r(
   DB::connection('my_connection')->getQueryLog()
);

2. Where to enable query log ?

For an HTTP request lifecycle, you can enable query log in the `handle` method of some `BeforeAnyDbQueryMiddleware` [middleware][1] and then retrieve the executed queries in the [`terminate`][2] method of the same middleware.

class BeforeAnyDbQueryMiddleware
{
    public function handle($request, Closure $next)
    {
        DB::enableQueryLog();
        return $next($request);
    }

    public function terminate($request, $response)
    {
        // Store or dump the log data...
        dd(
            DB::getQueryLog()
        );
    }
}

A middleware's chain will not run for artisan commands, so for CLI execution you can enable query log in the artisan.start event listener.

For example you can put it in the bootstrap/app.php file

$app['events']->listen('artisan.start', function(){
    DB::enableQueryLog();
});

3. Memory

Laravel keeps all queries in memory. So in some cases, such as when inserting a large number of rows, or having a long running job with a lot of queries, this can cause the application to use excess memory.

In most cases you will need the query log only for debugging, and if that is the case I would recommend you enable it only for development.

if (App::environment('local')) {
    // The environment is local
    DB::enableQueryLog();
}

References

https://laravel.com/docs/5.0/database#query-logging

Question 5

From laravel version 5.3^ there is a function to call the app name

config('app.name');

You can change the default name 'Laravel' inside this file

config/app.php

'name' => 'Laravel',

And also inside .env file

APP_NAME=your_app_name

for latter to work, in config/app.php the line where you set the name should be written like this: 'name' => env('APP_NAME', 'fallback_app_name'),

Question 6

this worked (ignore the dynamic stuff like this->getClassName etc).. the basic logic works just fine

public function scopeAddTranslations($query)
{
    $t = new Translation();

    $subq = $t->select('item','text as ref_ar')
              ->where('locale','=','ar')
              ->where('item','like',$this->getClassName().'.ref%');

    $query->leftjoin(DB::raw('('.$subq->toSql().') as t'), 
      function ($join) use ($subq) { 
          $join->on(DB::raw('SUBSTRING('.$this->getTable().'.ref_translation 
                              FROM 14 FOR 26)'),
                                 '=',
                                 DB::raw('t.item'))
                   ->addBinding($subq->getBindings());
            });
    return $query;
}