title: Crossing MySQL Tables
body: <p>I feel like this is something I can search for, but I don't know the correct terminology to go about it.</p>
  
  <p>I have a SQL database that has a a few tables. One table stores caller logs for a softphone (agent_log), one table stores campaign information for what the people on the softphone are calling on (campaigns). Both tables have the column "campaign_id" that I can use to call to each other (I think). I need to relate these two tables so that I can have a sql query that would look like </p>
  
  <pre><code>SELECT * FROM agent_log WHERE active = 'Y';
  </code></pre>
  
  <p>Obviously it doesn't work because the column 'active' doesn't exist in that table, it exists in the campaigns table. Is there any simple way to go about this?</p>