title: tagDatabase in Formatted SQL changeset
body: <p>I'm trying to tag a Formatted SQL changeset so a matching ID and tag are written to the DATABASECHANGELOG table (for rollback purposes - see changeset fragment below).  The Phing liquibase task is being used to apply the 'update' command for a single changelog.</p>
  
  <p>Although the 'tagDatabase' attribute isn't listed for Formatted SQL changelogs (<a href="http://www.liquibase.org/documentation/sql_format.html" rel="nofollow">http://www.liquibase.org/documentation/sql_format.html</a>), neither is logicalFilePath, and that seems to be working OK!</p>
  
  <p>Can someone let me know definitively if tagDatabase is not supported for a Formatted SQL changeset?</p>
  
  <p>Many thanks in advance,</p>
  
  <p>IR8</p>
  
  <p>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</p>
  
  <p>--changeset id:123 logicalFilePath:path-independent 
  ALTER TABLE test1 
  ADD COLUMN text_column 
  text NULL;</p>
  
  <p>--rollback ALTER TABLE test1 DROP COLUMN text_column;</p>
  
  <p>--changeset id:tag123 <strong>tagDatabase:123</strong>;</p>
  
  <p>++++++++++++++++++++++++++++++++++++++++++++++++++++++++++</p>
  
  <p>Unexpected error running Liquibase: No SQL for changeset ../db/changelog/databaseChangeLog.sql::tag123::id</p>
  
  <p>Execution of target "migrate" failed for the following reason: C:\data\htdocs\TestLiquibase\deploy\build.xml:49:1: Liquibase exited with code -1</p>