如何在Laravel 5中执行查询？DB :: getQueryLog（）返回空数组

默认情况下，Laravel 5中禁用了查询日志：https : //github.com/laravel/framework/commit/e0abfe5c49d225567cb4dfd56df9ef05cc297448文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

您将需要通过调用以下命令来启用查询日志：文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::enableQueryLog();文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

或注册一个事件监听器：文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::listen(文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

function ($sql, $bindings, $time) {文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

//  $sql - select * from `ncv_users` where `ncv_users`.`id` = ? limit 1文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

//  $bindings - [5]文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

//  $time(in milliseconds) - 0.38文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

}文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

);文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

一些技巧文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

1.多个数据库连接文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

如果您有多个数据库连接，则必须指定要记录的连接文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

启用查询日志my_connection：文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::connection('my_connection')->enableQueryLog();文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

获取以下查询日志my_connection：文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

print_r(文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::connection('my_connection')->getQueryLog()文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

);文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

2.在哪里启用查询日志？文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

对于HTTP请求生命周期，可以在handle某些BeforeAnyDbQueryMiddleware 中间件的方法中启用查询日志，然后terminate在同一中间件的方法中检索已执行的查询。文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

class BeforeAnyDbQueryMiddleware文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

{文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

public function handle($request, Closure $next)文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

{文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::enableQueryLog();文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

return $next($request);文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

}文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

public function terminate($request, $response)文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

{文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

// Store or dump the log data...文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

dd(文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::getQueryLog()文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

);文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

}文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

}文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

工匠命令不会运行中间件链，因此对于CLI执行，您可以在事件侦听器中启用查询日志。文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

例如，您可以将其放入bootstrap/文件中文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

$app['events']->listen('', function(){文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

\DB::enableQueryLog();文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

});文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

3.记忆文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

Laravel将所有查询保留在内存中。因此，在某些情况下，例如插入大量行或长时间运行带有大量查询的作业时，这可能导致应用程序使用过多的内存。文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

在大多数情况下，您仅需要查询日志进行调试，如果是这种情况，我建议您仅将其用于开发。文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

if (App::environment('local')) {文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

// The environment is local文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

DB::enableQueryLog();文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html

}文章源自菜鸟学院-https://www.cainiaoxueyuan.com/bc/17387.html