In the code below, the goal is to populate the likes field for every post. I am querying the posts table and converting the posts to an object. Based on a value in this converted result set, I'm querying the likes table and am trying to add the corresponding likes result set to the posts object dynamically as shown below.
The likes field seems to be added successfully within the map function. However, due to some issue with handling the promises, the likes field does not exist outside the then() code block.
Any idea why this is? I appreciate any assistance on how to resolve this issue.
router.post('/load', (req, res) => {
connection.then( (conn) => {
return conn.query("SELECT userId, postId FROM posts");
}).then( (postsRows) => {
let posts = postsRows.map((r) => Object.assign({}, r));
posts = posts.map( (post, i) => {
if( posts[i].totalLikes ) {
connection.then( (conn) => {
return conn.query("SELECT u.userId, u.first, u.last FROM likes l JOIN posts p ON p.postId = l.postId JOIN users u ON u.userId = l.userId WHERE p.postId = ?", [post.postId]);
}).then( (likesRows) => {
posts[i].likes = likesRows.map((r) => Object.assign({}, r));
});
}
});
return posts;
}).then( (posts) => {
console.log(posts);
});
});