title: how can I join multiple columns on two table in sql
body: <p>I have two table like below</p>
  <pre><code>create table test_user (
          id INT AUTO_INCREMENT PRIMARY KEY,
          name varchar(64)
  );
  
  create table test_info(
          id INT AUTO_INCREMENT PRIMARY KEY,
          sellerId INT,
          buyerId INT,
          x varchar,
          y varchar,
          z varchar
  );
  </code></pre>
  <p>how can I get all the information in table test_info and the name of the buyer AND the name of seller from the test_user table in the same statement?</p>
  <pre><code>select * from test_table join test_user on sellerId = test_user.id;
  or 
  select * from test_table join test_user on buyerId = test_user.id;
  </code></pre>
  <p>would just give me a seller or buyer but i would like to get the result for both</p>