Mysql / PHP从post.postid选择行的列中获取post.userid

Question

I am using Dreamweaver and MAMP to create a site. I have a table called posts inside I have two columns, postid, and userid. I'm putting all the posts on a page and I want to show which user posted which post, and write that on each post respectively. For example the first post that should show up has a postid of 2 and a userid of 1. Currently it is displaying the userid of the user who is logged in on all the posts, I am using:

mysql_select_db($database_akaearthdb, $akaearthdb);
$query_PostsUserid = "SELECT userid FROM posts WHERE posts.userid ORDER BY posts.postid";
$row_PostsUserid = mysql_fetch_assoc($PostsUserid);

and

echo $row_PostsUserid['userid']

To display it. I want $row_PostsUserid['userid'] to be the userid of the person who posted it.

Let me know if you need any more information, I'm new to the language so sorry if I'm doing everything wrong, TIA.

Answer 1

Before executing a query from any language,

Test the query on your local database command line.

Your query,

"SELECT userid FROM posts WHERE posts.userid ORDER BY posts.postid"

will result in a syntax error.

EDIT:

Do the following,

CREATE TABLE users (
         id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
         user_name VARCHAR(255),
         age INT,
         any_detail VARCHAR(255)
       );

CREATE TABLE posts (
         id INT NOT NULL AUTO_INCREMENT PRIMARY KEY,
         post TEXT,
         created_at TIMESTAMP(8),
         user_id INT,
         FOREIGN KEY (user_id) REFERENCES users(id)
       );

Now,

To display the posts,

Array =  SELECT * FROM posts ORDER BY created_at DESC;

Store the result from the above query into your languages array/variable. Im a rails developer, Im not sure about PHP's syntax.(Google it and find out!)

After storing the results into an array,

Display the following for each element in the array as follows,

Post content:
<< Array.post >>
Written about:
<< Array.created_at >> ago
Written by:
<< SELECT user_name FROM users WHERE user_id = Array.user_id >>

That should help or take you somewhere.