title: altering my sql table to add multiple new columns at once using liquibase
body: <p>What is the correct syntax to alter the table and adding multiple columns at a time using liquibase xml. The official document gives the example for adding only one column :</p>
  
  <pre><code>&lt;changeSet author="liquibase-docs" id="addColumn-example"&gt;
      &lt;addColumn catalogName="cat"
              schemaName="public"
              tableName="person"&gt;
          &lt;column name="address" type="varchar(255)"/&gt;
      &lt;/addColumn&gt;
  &lt;/changeSet&gt;
  </code></pre>
  
  <p>Now if I want to add multiple columns at a time, what is the correct syntax:</p>
  
  <pre><code>&lt;changeSet author="liquibase-docs" id="addColumn-example"&gt;
      &lt;addColumn catalogName="cat"
              schemaName="public"
              tableName="person"&gt;
          &lt;column name="job" type="varchar(255)"/&gt;
      &lt;/addColumn&gt;
      &lt;addColumn catalogName="cat"
              schemaName="public"
              tableName="person"&gt;
          &lt;column name="designation" type="varchar(255)"/&gt;
      &lt;/addColumn&gt;
  &lt;/changeSet&gt;
  </code></pre>
  
  <p>Is it correct or </p>
  
  <pre><code>&lt;changeSet author="liquibase-docs" id="addColumn-example"&gt;
      &lt;addColumn catalogName="cat"
              schemaName="public"
              tableName="person"&gt;
          &lt;column name="job" type="varchar(255)"/&gt;
         &lt;column name="designation" type="varchar(255)"/&gt;
      &lt;/addColumn&gt;   
  &lt;/changeSet&gt;
  </code></pre>
  
  <p>which is correct of the two above? or something different altogether. </p>