Print body of post like it does standard wordpress on start page

What function is for this?

$thispost = $wpdb->get_results("SELECT ID, post_title, DATE_FORMAT(post_modified, '%d.%m.%Y %H:%i') as post_date, post_author
        FROM $blogPostsTable WHERE post_status = 'publish'
        AND ID > $id_more_then
        AND post_type = 'post'
        AND post_date >= DATE_SUB(CURRENT_DATE(), INTERVAL $how_long DAY)
        ORDER BY id DESC LIMIT 0,1");

I want to print part of body and I want to print it with link (more…)

Are there function for printing this if I have post body and I have post ID (and blog ID)?

Look at this:
<?php query_posts(‘category_name=special_cat&showposts=10’); ?>
<?php while (have_posts()) : the_post(); ?>
<!– Do special_cat stuff… –>
<?php endwhile; ?>

This request is low flexible