Question

Can Sqlite NHibernate id generator be made compatible with Postgresql? I’m planning to unit test my NHibernate Postgresql project based on this http://ayende.com/Blog/archive/2009/04/28/nhibernate-unit-testing.aspx

If there is no compatible id generator, is there a way to signal NHibernate to ignore id generator when it is using different dialect?

<hibernate-mapping xmlns="urn:nhibernate-mapping-2.2" auto-import="true" assembly="RuntimeNhibernate" namespace="RuntimeNhibernate" >

  <class name="Blog" table="blog">
    <id name="BlogId" column="blog_id">
        <!-- can this be ignored when using different dialect.. -->
        <generator class="sequence"> 
            <param name="sequence">blog_id_seq</param>
        </generator> 
        <!-- ...can this -->
    </id>


    <property name="AllowsComments" column="allows_comments"/>
    <property name="CreatedAt" column="created_at"/>
    <property name="Subtitle" column="subtitle"/>
    <property name="Title" column="title"/>


  </class>

</hibernate-mapping>  

Error when using Sqlite dialect on Postgresql-specific mapping:

NHibernate.MappingException: could not instantiate id generator: sequence ---> 
NHibernate.MappingException: Dialect does not support sequences

Answer 1

My suggestion is that you use a DB-agnostic generator, like HiLo.