Why is DB::getQueryLog() Returning an Empty Array in Laravel 5?

Retrieving Query Execution Log in Laravel 5: Resolving DB::getQueryLog() Empty Array

When attempting to view the log for executed queries, developers may encounter an empty array return value from DB::getQueryLog(). To address this, it is essential to first enable the query log, which is disabled by default in Laravel 5 to optimize memory usage.

Enabling Query Log

• Method 1: Enable query logging for all connections:

DB::enableQueryLog();

• Method 2: Enable query logging for a specific connection (e.g., my_connection):

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

Retrieving Query Log

Once enabled, query logs can be retrieved using:

print_r(DB::getQueryLog());

• For multiple DB connections, specify the desired connection in the call above.

Middleware Approach

To enable query logging only during HTTP request lifecycle:

class LogQueryMiddleware
{
    public function handle($request, Closure $next)
    {
        DB::enableQueryLog();
        $response = $next($request);
        dd(DB::getQueryLog()); // Log queries here
        return $response;
    }
}

// Add the middleware to the app
app()->middleware([LogQueryMiddleware::class]);

Artisan Command Logging

For artisan commands, where middleware chains are not executed:

// In bootstrap/app.php
app()->events->listen('artisan.start', function() {
    DB::enableQueryLog();
});

Memory Management

Excessive queries can lead to memory issues. It's recommended to enable query logging only for debugging purposes:

if (app()->environment('local')) {
    DB::enableQueryLog();
}

By following these steps, developers can effectively view query logs and gain valuable insights into their application's database interactions.

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