DB:：QueryLog（）仅在使用$builder->get（）执行查询后才起作用。

如果要在执行查询之前或不执行查询时获取原始查询，可以使用$builder->toSql（）方法。

获取原始SQL并替换“？”的示例具有实际绑定值：

$query = str_replace(array('?'), array('\'%s\''), $builder->toSql());
$query = vsprintf($query, $builder->getBindings());
dump($query);

$result = $builder->get();

或者，您可以故意触发错误，例如，使用不存在的表或列。然后，您可以在异常消息中看到生成的查询。

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 ],
// ]

将此代码添加到AppServiceProvider并获取日志文件

         \DB::listen(function ($query) {
             \Log::info(
                 $query->sql,
                 $query->bindings,
                 $query->time
             );
         });

我通过监听查询日志并附加到日志数组来实现：

//create query
$query=DB::table(...)...->where(...)...->orderBy(...)...
$log=[];//array of log lines
...
//invoked on query execution if query log is enabled
DB::listen(function ($query)use(&$log){
    $log[]=$query;//enqueue query data to logs
});
//enable query log
DB::enableQueryLog();
$res=$query->get();//execute

为了记录所有执行的查询，可以使用DB:：enableQueryLog（）icw DB:：getQueryLog（（）。输出具有以下结构。

[
  [
    "query" => "select * from "users" where name = ?"
    "bindings" => ["John Doe"]
    "time" => 0.34
  ],
  ...
]

此外，我在这里结合了一些答案，以便获得完美的函数，用编译的绑定解析sql。见下文。我甚至创建了一个实现此功能的自定义生成器类，例如User:：where（'name'，'JohnDoe'）->parse（）；

function parse_sql(string $sql, array $bindings) : string
{
  $compiled_bindings  = array_map('compile_binding', $bindings);

  return preg_replace_array("/\?/", $compiled_bindings, $sql);
}

function compile_binding($binding)
{
  $grammar = new MySqlGrammar;

  if (is_bool($binding))
  {
    return (int)$binding; //This line depends on the database implementation
  }

  if(is_string($binding))
  {
    return "'$binding'";
  }

  if ($binding instanceof DateTimeInterface)
  {
    return $binding->format($grammar->getDateFormat());
  }

  return $binding;
}

有一种获取查询字符串的方法。

到SQL（）

在我们的情况下，

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

回来

select * from users

是返回SQL查询字符串的确切解决方案。。希望这有帮助。。。