Get all posts with help of WP_Query - wordpress

Question

I need get all posts of site. I try do it in widget, that I made myself, but result is empty.
global $post;
$args = array(
'post_type' => 'post',
'post_status' => 'publish'
);
$query = new WP_Query( $args );
if ( $query->have_posts() ) {
while ($query->have_posts()) {
$query->the_post();
var_dump($post->ID);
}
}
And when I add in argument array parameter cat then return posts, but I need get all posts from all categories, not just from specified categories.
$args = array(
'post_type' => 'post',
'post_status' => 'publish',
'cat' => 22
);

Answer 1

Make sure the global $post is in the same function/scope.
If it still not working, instead of var_dump($post->ID) try:
var_dump($query->post->ID)
And don't forget to call wp_reset_postdata() after the while loop.

Answer 2

Try this:
$args = array(
'post_type' => 'post',
'posts_per_page' => -1
);
$the_query = new WP_Query( $args );
if ( $the_query->have_posts() ) :
while ( $the_query->have_posts() ) : $the_query->the_post();
the_title();
the_content();
endwhile;
wp_reset_postdata();
endif;

Answer 3

set posts_per_page to -1, this will return all posts from db.
$args = array(
'posts_per_page' => -1,
'post_type' => 'post',
);
$the_query = new WP_Query( $args );
while ( $the_query->have_posts() ) {
// do stuff
}

Answer 4

I understood problem, on site (where I working in current time) was installed polylang, and when I specify for function get_posts in arguments 'lang' => pll_current_language() it return all posts for current language.
$results = get_posts(
array(
'numberposts' => 9999,
'orderby' => 'rand',
'order' => 'ASC',
'post_type' => 'post',
'post_status' => 'publish',
'lang' => pll_current_language()
)
);