Support For Other Databases

Since XPlanner uses the Hibernate object-relational mapping layer, XPlanner should work with any database which Hibernate supports. Hibernate currently supports quite a few databases, and the list of supported databases is rapidly growing.

Note: Although Hibernate "supports" many databases, it doesn't mean the Hibernate-generated schema and queries will be compatible with all those databases.

Clashes with Proprietary Reserved Keywords

Many databases have nonstandard proprietary keywords that cannot be used in their database schema. Fortunately, this problem can be addressed in the Hibernate mapping layer by modifying the column name mapping. For example:

Test 1 2 3

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD//EN"
        "http://hibernate.sourceforge.net/hibernate-mapping-2.0.dtd">

<hibernate-mapping>
    <class name="com.technoetic.xplanner.domain.Note" table="note" >
        <id name="id"><generator 

              class="com.technoetic.xplanner.db.hibernate.HibernateIdentityGenerator"/>
        </id>
        <property name="attachedToId" column="attachedTo_id"/>
        <property name="authorId" column="author_id"/>
        <property name="subject"/>
        <property name="body" length="4000"/>
        <property name="file" type="binary"/>
        <property name="filename"/>
        <property name="fileSize" column="file_size"/>
        <property name="contentType" column="content_type"/>
        <property name="submissionTime" column="submission_time"/>
        <property name="lastUpdateTime" column="last_update"  type="timestamp" />
    </class>
</hibernate-mapping>

 <property name="body" length="4000"/>

 <property name="file" column="xfile" type="binary"/>

 <property name="filename"/>

The downside of this approach is that handedited mapping files may not remain consistent with mappings in future versions of XPlanner. Starting with XPlanner 0.5.3 you can also use XSLT transforms to automatically rewrite the mapping files. Two mappings are included in the XPlanner distribution: Oracle and PostgreSQL. The Oracle mapping transformation is...

<?xml version="1.0"?>
<xsl:transform xmlns:xsl="http://www.w3.org/1999/XSL/Transform" version="1.0">
    <xsl:output method="xml"
        doctype-public='-//Hibernate/Hibernate Mapping DTD//EN'
        doctype-system='http://hibernate.sourceforge.net/hibernate-mapping-1.1.dtd'/>


    <xsl:template match="*|@*|text()">
      <xsl:copy>
        <xsl:apply-templates select="*|@*|text()" />
      </xsl:copy>
    </xsl:template>


    <xsl:template match="//class[@name='com.technoetic.xplanner.domain.Note']/property[@name='file']/@name">
      <xsl:copy-of select="."/>
      <xsl:attribute name="column">xfile</xsl:attribute>
    </xsl:template>


</xsl:transform

This transformation will automatically add a "column='xfile'" attribute to the file propery if the Note mapping. To configure XPlanner to use the mapping transformation add the following property to your database-related properties:

xplanner.hibernate.mappingtransform=oracle-mapping-transform.xsl

Of course, substitute the mapping transform file for your desired database.

Problems with Hibernate Mapped Data Types

There are small problems with the Hibernate "dialects" defined for some databases. Currently, there are customized dialects included with XPlanner.