title: SQL error: 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax'
body: <p>I have this sql query</p>
  
  <pre><code>SELECT sites.id, sites.url, GROUP_CONCAT(categories.name,"|",
      categories.color SEPARATOR ",") AS categories
  FROM sites
  LEFT JOIN categories_data ON sites.id = categories_data.sites_id
  LEFT JOIN categories ON categories_data.categories_id = categories.id
  WHERE sites.deleted=0 
  AND WHERE categories.deleted=0 
  AND WHERE categories_data.deleted=0 
  GROUP BY sites.id
  </code></pre>
  
  <p>I get this error:</p>
  
  <pre><code>Database_Exception [ 1064 ]: You have an error in your SQL syntax; 
  check the manual that corresponds to your MySQL server version for 
  the right syntax to use near 'WHERE categories.deleted=0 AND WHERE 
  categories_data.deleted=0 GROUP BY sites.id' at line 5 [ SELECT sites.id, 
  sites.url, GROUP_CONCAT(categories.name,"|",categories.color SEPARATOR ",") 
  AS categories FROM sites LEFT JOIN categories_data ON sites.id = 
  categories_data.sites_id LEFT JOIN categories ON 
  categories_data.categories_id = categories.id WHERE sites.deleted=0 
  AND WHERE categories.deleted=0 AND WHERE categories_data.deleted=0 GROUP BY 
  sites.id ]
  </code></pre>
  
  <p>What does this error mean?</p>