Programmatically create wordpress post and add category/tags with them

wp_create_post.php

<?php 

// Guessing this script is placed in the root wordpress directory.
// If not, change the require_once statements script path accordingly.
require_once('wp-load.php');
require_once('wp-admin/includes/taxonomy.php');

// Connect to database and get data
$conn = new mysqli('localhost', 'username', 'password', 'databasename');
if ($conn->connect_error) {
	die('Connection failed');
}

$result = $conn->query("SELECT title, content, category, tag FROM table");
if ($result->num_rows > 0) {
	while($row = $result->fetch_assoc()) {
		$post = [
			'post_title' => $row['title'],
			'post_content' => $row['content'],
			'post_status' => 'publish', // or can be 'draft'
			'post_author' => 1 // The default first user
		];
		
		$post_id = wp_insert_post($post);
		
    // Add the category name as category
    wp_set_object_terms($post_id, $row['category'], 'category');
		
    // Add tag data as post tag
    wp_set_object_terms($post_id, $row['tag'], 'post_tag');
	}
}

// Done.