在我看来，这将是初学者的最佳方法：

echo "<pre>";
print_r($query->toSql());
print_r($query->getBindings());

这里也描述了这一点。https://stackoverflow.com/a/59207557/9573341

以下是我使用的解决方案：

DB::listen(function ($sql, $bindings, $time) {
    $bound = preg_replace_callback("/\?/", function($matches) use ($bindings) {
        static $localBindings;
        if (!isset($localBindings)) {
            $localBindings = $bindings;
        }
        $val = array_shift($localBindings);

        switch (gettype($val)) {
            case "boolean":
                $val = ($val === TRUE) ? 1 : 0;  // mysql doesn't support BOOL data types, ints are widely used
                // $val = ($val === TRUE) ? "'t'" : "'f'";   // todo: use this line instead of the above for postgres and others
                break;

            case "NULL":
                $val = "NULL";
                break;

            case "string":
            case "object":
                $val = "'". addslashes($val). "'";   // correct escaping would depend on the RDBMS
                break;
        }
        return $val;
    }, $sql);
    array_map(function($x) { 
        (new \Illuminate\Support\Debug\Dumper)->dump($x); 
    }, [$sql, $bindings, $bound]);
});

请阅读代码中的注释。我知道，它并不完美，但对于我的日常调试来说，它还可以。它试图以或多或少的可靠性构建绑定查询。但是，不要完全信任它，数据库引擎以不同的方式对值进行转义，而这个短函数并没有实现这些值。所以，仔细观察结果。

从Laravel 5.8.15开始，查询生成器现在有dd和dump方法

DB::table('data')->where('a', 1)->dump();

如果您试图使用Illuminate而不使用Laravel获取日志，请使用：

\Illuminate\Database\Capsule\Manager::getQueryLog();

你也可以像这样设置一个快速功能：

function logger()
{
    $queries = \Illuminate\Database\Capsule\Manager::getQueryLog();
    $formattedQueries = [];
    foreach ($queries as $query) :
        $prep = $query['query'];

        foreach ($query['bindings'] as $binding) :

            if (is_bool($binding)) {
                $val = $binding === true ? 'TRUE' : 'FALSE';
            } else if (is_numeric($binding)) {
                $val = $binding;
            } else {
                $val = "'$binding'";
            }

            $prep = preg_replace("#\?#", $val, $prep, 1);
        endforeach;
        $formattedQueries[] = $prep;
    endforeach;
    return $formattedQueries;
}

EDIT

更新的版本似乎在默认情况下禁用了查询日志记录（上面返回了一个空数组）。要重新启用，在初始化Capsule Manager时，获取连接的实例并调用enableQueryLog方法

$capsule::connection()->enableQueryLog();

再次编辑

考虑到实际问题，您实际上可以执行以下操作来转换当前的单个查询，而不是之前的所有查询：

$sql = $query->toSql();
$bindings = $query->getBindings();

如果您正在使用修补程序并希望记录形成的SQL查询，可以执行以下操作

$ php artisan tinker
Psy Shell v0.9.9 (PHP 7.3.5 — cli) by Justin Hileman
>>> DB::listen(function ($query) { dump($query->sql); dump($query->bindings); dump($query->time); });
=> null
>>> App\User::find(1)
"select * from `users` where `users`.`id` = ? limit 1"
array:1 [
  0 => 1
]
6.99
=> App\User {#3131
     id: 1,
     name: "admin",
     email: "admin@example.com",
     created_at: "2019-01-11 19:06:23",
     updated_at: "2019-01-11 19:06:23",
   }
>>>

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 ],
// ]