title: MySQL illegal mix of collations when everything is collated the same
body: <p>I can run this query in MySQL and it works just fine. BUT, I need to do a LEFT function on ctd.FULL_DESCRIPTION (TEXT datatype) and take just the first 3600 characters and when I try to do that (using LEFT(ctd.FULL_DESCIPTION, 3600)) I get the error: illegal mix of collations (utf8_general_ci,IMPLICIT) and (latin1_swedish_ci,COERCIBLE) for operation 'UNION'</p>
  
  <p>Everything I can find on this error suggests that one of my columns is not collated the same as the others. I did a SHOW FULL COLUMNS on all the tables in this query and everything that's collated is using utf8_general_ci. The default collation of the database is also utf8. I can't find where it's getting latin1_swedish_ci anywhere. What am I missing?</p>
  
  <pre><code>SELECT 
  CONCAT(''73'',RIGHT(CONCAT(''000000'',cd.CHANGEID),6)) AS CHANGEID, 
  LEFT(cd.TITLE,80) AS CHANGETITLE, FROM_UNIXTIME(cd.CREATEDTIME/1000) AS PRJDATE, 
  LEFT(sd.NAME,10) AS STATUSNAME, wo.WORKORDERID AS WOID, LEFT(wo.TITLE,80) AS WOTITLE,
  LEFT(au.FIRST_NAME,10) as TECHNAME, ctd.FULL_DESCRIPTION AS CHANGEDSC
  FROM servicedesk.changedetails cd, servicedesk.incidenttochangemapping itcm, 
  servicedesk.workorder wo, servicedesk.stagedefinition sd, servicedesk.workorderstates 
  wos, servicedesk.sduser sdu, servicedesk.aaauser au, servicedesk.changetodescription ctd 
  WHERE cd.CHANGEID = itcm.CHANGEID and itcm.WORKORDERID = wo.WORKORDERID and
  cd.STAGEID = sd.STAGEID and wo.WORKORDERID = wos.WORKORDERID and wos.OWNERID = 
  sdu.USERID and sdu.USERID = au.USER_ID and cd.CHANGEID = ctd.CHANGEID and
  cd.STAGEID NOT IN (3,2) and cd.CATEGORYID IN 
  (301,2701,3601,3602,3605,3606,4201,4202,4501,4502,4801) and wos.REQUESTTYPEID IN 
  (301,601)
  UNION
  SELECT CONCAT(''73'',RIGHT(CONCAT(''000000'',cd.CHANGEID),6)) AS CHANGEID, 
  LEFT(cd.TITLE,80) AS CHANGETITLE, FROM_UNIXTIME(cd.CREATEDTIME/1000) AS PRJDATE, 
  LEFT(sd.NAME,10) AS STATUSNAME, '''' AS WOID, '''' AS WOTITLE, '''' AS TECHNAME, 
  ctd.FULL_DESCRIPTION AS CHANGEDSC
  FROM servicedesk.changedetails cd, servicedesk.stagedefinition sd,
  servicedesk.changetodescription ctd
  WHERE cd.STAGEID = sd.STAGEID and cd.CHANGEID = ctd.CHANGEID and cd.STAGEID NOT 
  IN (3,2) and cd.CATEGORYID IN
  (301,2701,3601,3602,3605,3606,4201,4202,4501,4502,4801) and NOT EXISTS (
  SELECT NULL FROM servicedesk.incidenttochangemapping itcm WHERE cd.CHANGEID = 
  itcm.CHANGEID)
  </code></pre>