[jboss-cvs] jboss-seam/doc/reference/en/modules ...

[Gavin King]

  User: gavin   
  Date: 07/02/25 17:14:54

  Modified:    doc/reference/en/modules   persistence.xml tutorial.xml
  Log:
  EL in QL
  
  Revision  Changes    Path
  1.8       +32 -0     jboss-seam/doc/reference/en/modules/persistence.xml
  
  (In the diff below, changes in quantity of whitespace are not shown.)
  
  Index: persistence.xml
  ===================================================================
  RCS file: /cvsroot/jboss/jboss-seam/doc/reference/en/modules/persistence.xml,v
  retrieving revision 1.7
  retrieving revision 1.8
  diff -u -b -r1.7 -r1.8
  --- persistence.xml	4 Feb 2007 17:42:27 -0000	1.7
  +++ persistence.xml	25 Feb 2007 22:14:53 -0000	1.8
  @@ -414,6 +414,38 @@
       </section>
       
       <section>
  +        <title>Using EL in EJB-QL/HQL</title>
  +        <para>
  +            Seam proxies the <literal>EntityManager</literal> or <literal>Session</literal>
  +            object whenever you use a Seam-managed persistence context or inject a container
  +            managed persistence context using <literal>@PersistenceContext</literal>. This
  +            lets you use EL expressions in your query strings, safely and efficiently. For
  +            example, this:
  +        </para>
  +        
  +        <programlisting><![CDATA[User user = em.createQuery("from User where username=#{user.username}")
  +         .getSingleResult();]]></programlisting>
  +         
  +        <para>is equivalent to:</para>
  +         
  +        <programlisting><![CDATA[User user = em.createQuery("from User where username=:username")
  +         .setParameter("username", user.getUsername())
  +         .getSingleResult();]]></programlisting>
  +         
  +        <para>
  +            Of course, you should never, ever write it like this:
  +        </para>
  +        
  +        <programlisting><![CDATA[User user = em.createQuery("from User where username=" + user.getUsername()) //BAD!
  +         .getSingleResult();]]></programlisting>
  +         
  +        <para>
  +            (It is inefficient and vulnerable to SQL injection attacks.)
  +        </para>
  +        
  +    </section>
  +    
  +    <section>
           <title>Using Hibernate filters</title>
           
           <para>
  
  
  
  1.79      +10 -2     jboss-seam/doc/reference/en/modules/tutorial.xml
  
  (In the diff below, changes in quantity of whitespace are not shown.)
  
  Index: tutorial.xml
  ===================================================================
  RCS file: /cvsroot/jboss/jboss-seam/doc/reference/en/modules/tutorial.xml,v
  retrieving revision 1.78
  retrieving revision 1.79
  diff -u -b -r1.78 -r1.79
  --- tutorial.xml	24 Feb 2007 18:38:40 -0000	1.78
  +++ tutorial.xml	25 Feb 2007 22:14:53 -0000	1.79
  @@ -345,6 +345,7 @@
                       <area id="registration-persistencecontext-annotation" coords="9"/>
                       <area id="registration-logger-annotation" coords="12"/>
                       <area id="registration-action-listener" coords="15"/>
  +                    <area id="registration-query" coords="18"/>
                       <area id="registration-log" coords="24"/>
                       <area id="registration-outcome" coords="25"/>
                       <area id="registration-builtin" coords="29"/>
  @@ -365,8 +366,8 @@
      
      public String register()
      {
  -      List existing = em.createQuery("select username from User where username=:username")
  -         .setParameter("username", user.getUsername())
  +      List existing = em.createQuery(
  +         "select username from User where username=#{user.username}")
            .getResultList();
            
         if (existing.size()==0)
  @@ -419,6 +420,13 @@
                           <literal>register()</literal> method is called, and committed when it completes.
                       </para>
                   </callout>
  +                <callout arearefs="registration-query">
  +                    <para>
  +                        Notice that Seam lets you use a JSF EL expression inside EJB-QL. Under the covers,
  +                        this results in an ordinary JPA <literal>setParameter()</literal> call on the
  +                        standard JPA <literal>Query</literal> object. Nice, huh?
  +                    </para>
  +                </callout>
                   <callout arearefs="registration-log">
                       <para>
                           The <literal>Log</literal> API lets us easily display templated log messages.