要将上次运行的查询输出到屏幕，可以使用以下命令：

\DB::enableQueryLog(); // Enable query log

// Your Eloquent query executed by using get()

dd(\DB::getQueryLog()); // Show results of log

我相信最近的查询将位于阵列的底部。

你会得到这样的东西：

array(1) {
  [0]=>
  array(3) {
    ["query"]=>
    string(21) "select * from "users""
    ["bindings"]=>
    array(0) {
    }
    ["time"]=>
    string(4) "0.92"
  }
}

（感谢约书亚在下面的评论。）

$data = User::toSql();
echo $data; //this will retrun select * from users. //here User is model

您可以使用toSql方法-最简单的方法

DB::table('users')->toSql();

此外，如果您的查询中有绑定，并且希望查看带有绑定的查询。你不能用这样的东西：

$query = DB::table('table')->whereIn('some_field', [1,2,30]); 

$sql_with_bindings = str_replace_array('?', $query->getBindings(), $query->toSql());

dd($sql_with_bindings);

对于laravel 5.5.X

如果希望接收应用程序执行的每个SQL查询，可以使用listen方法。此方法对于记录查询或调试非常有用。您可以在服务提供商中注册查询侦听器：

<?php

namespace App\Providers;

use Illuminate\Support\Facades\DB;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{
    /**
     * Bootstrap any application services.
     *
     * @return void
     */
    public function boot()
    {
        DB::listen(function ($query) {
            // $query->sql
            // $query->bindings
            // $query->time
        });
    }

    /**
     * Register the service provider.
     *
     * @return void
     */
    public function register()
    {
        //
    }
}

来源

下面是一个完美的例子：

https://laravel.com/docs/5.8/database#listening-用于查询事件

打开app\Providers\AppServiceProvider.php并将以下内容添加到Boot（）函数中：

DB::listen(function ($query) {
    var_dump([
        $query->sql,
        $query->bindings,
        $query->time
    ]);
});

因此，您不需要在每个函数中放置DB:：enableQuerylog（）和DB:：getQuerylog（（）。

我创建了一些简单的函数来从一些查询中获取SQL和绑定。

/**
 * getSql
 *
 * Usage:
 * getSql( DB::table("users") )
 * 
 * Get the current SQL and bindings
 * 
 * @param  mixed  $query  Relation / Eloquent Builder / Query Builder
 * @return array          Array with sql and bindings or else false
 */
function getSql($query)
{
    if( $query instanceof Illuminate\Database\Eloquent\Relations\Relation )
    {
        $query = $query->getBaseQuery();
    }

    if( $query instanceof Illuminate\Database\Eloquent\Builder )
    {
        $query = $query->getQuery();
    }

    if( $query instanceof Illuminate\Database\Query\Builder )
    {
        return [ 'query' => $query->toSql(), 'bindings' => $query->getBindings() ];
    }

    return false;
}

/**
 * logQuery
 *
 * Get the SQL from a query in a closure
 *
 * Usage:
 * logQueries(function() {
 *     return User::first()->applications;
 * });
 * 
 * @param  closure $callback              function to call some queries in
 * @return Illuminate\Support\Collection  Collection of queries
 */
function logQueries(closure $callback) 
{
    // check if query logging is enabled
    $logging = DB::logging();

    // Get number of queries
    $numberOfQueries = count(DB::getQueryLog());

    // if logging not enabled, temporarily enable it
    if( !$logging ) DB::enableQueryLog();

    $query = $callback();

    $lastQuery = getSql($query);

    // Get querylog
    $queries = new Illuminate\Support\Collection( DB::getQueryLog() );

    // calculate the number of queries done in callback
    $queryCount = $queries->count() - $numberOfQueries;

    // Get last queries
    $lastQueries = $queries->take(-$queryCount);

    // disable query logging
    if( !$logging ) DB::disableQueryLog();

    // if callback returns a builder object, return the sql and bindings of it
    if( $lastQuery )
    {
        $lastQueries->push($lastQuery);
    }

    return $lastQueries;
}

用法：

getSql( DB::table('users') );
// returns 
// [
//     "sql" => "select * from `users`",
//     "bindings" => [],
// ]

getSql( $project->rooms() );
// returns
// [
//     "sql" => "select * from `rooms` where `rooms`.`project_id` = ? and `rooms`.`project_id` is not null",
//     "bindings" => [ 7 ],
// ]