title: How to build a WHERE-clause in a LiquiBase changeset
body: <p>How do I have to define a changeset in 'LiquiBase' notation for updating a table column whith an AND-ed WHERE-clause:</p>
  
  <pre><code>&lt;changeSet id="ddl update tables : modify datatype for MY_TABLE.STATE_ABBREV" author="xxx"&gt;
      &lt;preConditions onFail="MARK_RAN" onFailMessage="Column MY_TABLE.STATE_ABBREV doesn't exists."&gt;
          &lt;and&gt;
              &lt;tableExists tableName="MY_TABLE"/&gt;
              &lt;columnExists tableName="MY_TABLE" columnName="STATE_ABBREV"/&gt;
          &lt;/and&gt;
      &lt;/preConditions&gt;
      &lt;update tableName="MY_TABLE"&gt;
          &lt;column name="STATE_ABBREV" value="AS"/&gt;
          &lt;where&gt;AGU   /***AND STATE_ID=3***/  ??????????????????
          &lt;/where&gt;
      &lt;/update&gt;
  &lt;/changeSet&gt;
  </code></pre>