php - Eloquent model not updating updated_at timestamp -

i'm using laravel 5.1. make simple, have following code

migration:

schema::create('sitemap_data', function (blueprint $table) {     // primary , foreign keys     $table->increments('id');     $table->string('posturl');     // database functions     $table->timestamps(); }); 

and code somewhere else i'm using

$sitemapdata = sitemapdata::firstornew([                 'posturl' => $post             ]); $sitemapdata->save(); 

now, according laravel documentation

again, updated_at timestamp automatically updated, there no need manually set value

the updated_at value should updated in table. however, not happening.

it get's set on first insert, not on updating. when manually, this

$sitemapdata = sitemapdata::firstornew([                     'posturl' => $post                 ]); $sitemapdata->updated_at = carbon::now(); $sitemapdata->save(); 

it works. however, docs should happend automatically, wrong here?

i've searched sites on stackoverflow question, ones found laravel 3 or 4.1, 4.2 etc.

how correctly?

as mentioned in comments, if model did not change timestamps wont updated. if need update them, or want check if working fine use $model->touch() - more here