From a db?
Displaytag will never support retrieving data from a db directly. Displaytag is here to help you in displaying data, not to retrieve them.

Anyway, there are a couple of easy methods to get records from a db and display them using displaytag:

...

 2 ) Using dynabeans

see 

<%
      Connection con = ...; // just open a connection

      Statement stmt = con.createStatement();
      ResultSet rs = stmt.executeQuery("SELECT * from table");
      RowSetDynaClass resultSet =  new  RowSetDynaClass(rs, false);
      stmt.close();
      con.close();
      request.setAttribute("results", resultSet);
%>

      <display:table name="requestScope.results.rows" />
--------------------------------------------------------------------------------

<jsp:root version="1.2" xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:display="urn:jsptld:http://displaytag.sf.net">
  <jsp:directive.page contentType="text/html; charset=UTF-8" />
  <jsp:directive.page  import ="org.displaytag.sample.*" />
  <jsp:include page="inc/header.jsp" flush="true" />

  <jsp:scriptlet> Object foo = session.getAttribute( "test" );
    if ( foo ==  null  ) {
      session.setAttribute( "test",  new  TestList( 120 , false) );
   }
</jsp:scriptlet>

  <h2>Auto-paging of  long  lists</h2>

  <display:table name="sessionScope.test" pagesize="10">
    <display:column property="id" title="ID" />
    <display:column property="name" />
    <display:column property="email" />
    <display:column property="status" />
  </display:table>
  <jsp:include page="inc/footer.jsp" flush="true" />

</jsp:root>

<jsp:root version="1.2" xmlns:jsp="http://java.sun.com/JSP/Page" xmlns:display="urn:jsptld:http://displaytag.sf.net">
  <jsp:directive.page contentType="text/html; charset=UTF-8" />
  <jsp:directive.page  import ="org.displaytag.sample.*" />
  <jsp:include page="inc/header.jsp" flush="true" />

  <%
      Connection con = ...; // just open a connection

      Statement stmt = con.createStatement();
      ResultSet rs = stmt.executeQuery("SELECT * from table");
      RowSetDynaClass resultSet =  new  RowSetDynaClass(rs, false);
      stmt.close();
      con.close();
      request.setAttribute("results", resultSet);
%>

      <display:table name="requestScope.results.rows" />
    <display:column property="id" title="ID" />
    <display:column property="name" />
    <display:column property="email" />
    <display:column property="status" />
  </display:table>

 

  <jsp:include page="inc/footer.jsp" flush="true" />

</jsp:root>