title: Which table exactly is the "left" table and "right" table in a JOIN statement (SQL)?
body: <p>What makes a given table the left table?</p>
  
  <p>Is it that the table is indicated in the "From" part of the query?</p>
  
  <p>Or, is it the left table because it is on the left hand side of the = operator?</p>
  
  <p>Are the following equivalent</p>
  
  <pre><code>SELECT *
  FROM left_table
  LEFT JOIN right_table ON left_table.right_id = right_table.id
  </code></pre>
  
  <p>and</p>
  
  <pre><code>SELECT *
  FROM left_table
  LEFT JOIN right_table on right_table.left_id = left_table.id
  </code></pre>
  
  <p>???</p>
  
  <p>Thanks</p>