MySQL JOIN无法正常工作

Question

I am trying to complete a MySQL join from one table to another but it is not working. Ideally, I want to be able to do with with prepared statements (as it is more secure) but for now I am just trying to get this to work normally.

Here is my database setup:

Posts:

id | title | text 

1  | Evening | Something here...
2  | Trip away | Bets place to go...

Tags:

post_id | tag
1       | weather 
1       | Autumn 
2       | Holidays

This is my attempt so far:

  $tag = mysqli_real_escape_string($_GET['tag']);
  $select = mysqli_query($mysqli, "SELECT posts.id, posts.title FROM posts INNER JOIN tags ON tags.tag = ".$tag);

However this does not work. What I am trying to do is select all the posts with the relevant tag that has been searched for and then output this to the user. Please help I am really stuck

Edit: While loop the outputted data

  $select = mysqli_query($mysqli, "SELECT posts.id, posts.title FROM posts INNER JOIN tags ON tags.post_id = posts.id WHERE tags.tag = ".$tag);

  while($row = mysqli_fetch_array($select)) {

    echo print_r($row);

  }

Answer 1

your inner join syntax is incorrect

SELECT posts.id, posts.title 
FROM posts 
INNER JOIN tags ON tags.post_id = posts.id 
WHERE tags.tag = "some_tag_here"

you need to join the two tables together and then use a WHERE to filter by tag