Reverse Engineering database with Eclipse plugin

vace117 · **Joined:** Wed Jun 22, 2005 3:58 am **Posts:** 14

I tried to use the reverse engineering feature of the Eclipse plugin and I have a question about a certain peculiarity I noticed.

The mapping files were generated very well. For example:

Mapping documents:

Code:

<hibernate-mapping>
<!--
        Auto-generated mapping file from
        the hibernate.org cfg2hbm engine
-->
  <class name="com.allcorp.premium.coverage.data.orm.classes.XatAutoCovrg" table="XAT_AUTO_COVRG" schema="ALLIDB" catalog="R0234376" lazy="false">
    <composite-id name="id" class="com.allcorp.premium.coverage.data.orm.classes.XatAutoCovrgId">
      <key-property name="AcvProduct" type="java.lang.Character">
        <column name="ACV_PRODUCT" scale="8" precision="0" not-null="true" sql-type="CHAR" />
      </key-property>
... etc

So, we have a column declared as CHAR(8) in the database.

Here is the code generated for this mapping:

Code:

package com.allcorp.premium.coverage.data.orm.classes;


/**
 * XatAutoCovrgId generated by hbm2java
 */
public class XatAutoCovrgId  implements java.io.Serializable {

    // Fields   

 private java.lang.Character AcvProduct;
 private java.lang.Character AcvProductType;
 private java.lang.Character AcvVehicleType;
 private java.lang.Short AcvVersion;

... etc

Notice how the java type chosen for the CHAR(8) column is a java.lang.Character, which only takes 1 character instead of 8.

Why is hbm2java doing it this way?

Hibernate version: 3.0.5

brunosouza · **Joined:** Thu Jun 23, 2005 1:23 pm **Posts:** 3

I have the same issue here. I think that you can customize this with the reveng.xml file. See topic "3.2 hibernate.reveng.xml file" at http://www.hibernate.org/hib_docs/tools/ant/index.html

[]'s
Bruno

max · **Posted:** Mon Jun 27, 2005 3:25 am

we should be able to provide i better default I agree.

submit a jira for it.
until then use reveng.xml to work around it.

vace117 · **Joined:** Wed Jun 22, 2005 3:58 am **Posts:** 14

Is there a way to make the Eclipse Reverse Engineer plugin use the hibernate.reveng.xml file?

I know it can be specified with revengfile attribute of the <jdbcconfiguration> task, but I don't see anything in the plugin.

max · **Posted:** Wed Jun 29, 2005 1:32 am

there is overrivde xml field in the artifact generation

vace117 · **Joined:** Wed Jun 22, 2005 3:58 am **Posts:** 14

ok, I upgraded to hibernate-tools-3.0.0.alpha4a and used the "Override XML" field to point to my hibernate.reveng.xml file.

The file looks like this:

Code:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-reverse-engineering PUBLIC "-//Hibernate/Hibernate Reverse Engineering DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-reverse-engineering-3.0.dtd" >

<hibernate-reverse-engineering>
   <type-mapping>
      <sql-type jdbc-type="CHAR" hibernate-type="string" />
   </type-mapping>
</hibernate-reverse-engineering>

I would expect this to result in all CHAR fields being mapped to strings, but they are still being mapped like this:

Code:

        <property name="acvPipCd" type="character">
            <column name="ACV_PIP_CD" length="1" not-null="true" />
        </property>

What am I still missing?

Thanks

max · **Posted:** Wed Jun 29, 2005 3:07 pm

hmm - it should work.

are you sure that the return type from the database actually is a javax.sql.Types.CHAR ?

vace117 · **Joined:** Wed Jun 22, 2005 3:58 am **Posts:** 14

How would I find out if Hibernate tools interpret the CHAR column in the db as javax.sql.Types.CHAR?

The database type is definately CHAR:

Code:

select COLUMN_NAME, DATA_TYPE, LENGTH from SYSCOLUMNS where table_name='XAT_AUTO_COVRG' and COLUMN_NAME='ACV_PIP_CD' ;

COLUMN_NAME          DATA_TYPE      LENGTH     
-------------------- --------- -----------
ACV_PIP_CD           CHAR                1

  1 record(s) selected.

max · **Posted:** Thu Jun 30, 2005 1:32 am

put a log4j.properties in the classpath of the tools (easiest with ant - in eclipse you would need to add it to one of its jars)

then see in the debug log how it interpret the column

max · **Posted:** Thu Jun 30, 2005 5:00 am

just verified this...

in the current version you need to specify either length, precision or scale.

so this should work for your case:

Code:

<sql-type jdbc-type="CHAR" length='1' hibernate-type="string" />

max · **Posted:** Thu Jun 30, 2005 5:27 am

btw.

reported, fixed and committed

http://opensource.atlassian.com/project ... se/HBX-318