Hibernate 2.1.3
Spring 1.0
SQL Server 2000 with jtds 0.8rc1

I wrote this Mapping statement:

<map
name="articlesImpl"
table="composite_art_childs"
lazy="false"
sort="unsorted"
inverse="false"
cascade="all"
>

<key
column="composite_art_id"
/>

<index-many-to-many
class="de.pds.dom.dao.art.impl.ComponentArticleImpl"
column="article_id"
/>

<element
column="factor"
type="big_decimal"
not-null="false"
unique="false"
>
<column name="factor" sql-type="NUMERIC(19,4)"/>
</element>

</map>

In the element definition I don't use an Empty Element-Tag to define a sql-type for the element column. My Mapping is parsed and accepted by hibernate. I also have taken a look into the hibernate-mapping-2.0.dtd and my above statement is allowed.

Unfortunately this is ignored by hibernate I got this message in the log file:
[..]

2004-05-01 15:05:18,615 ERROR [net.sf.hibernate.tool.hbm2ddl.SchemaExport] - <Unsuccessful: create table composite_art_childs (composite_art_id NUMERIC(19,0) not null, factor NUMERIC(19,255) null , article_id NUMERIC(19,0) not null, primary key (composite_art_id, article_id))>

2004-05-01 15:05:18,625 ERROR [net.sf.hibernate.tool.hbm2ddl.SchemaExport] - <Die Anzahl von Dezimalstellen (255) f

Well, after some diving into the hbm2ddl and dialect code I found a solution / workaround:

<element
column="factor"
type="big_decimal"
length="4"
not-null="false"
unique="false"
/>


big_decimal is mapped to java.sql.Type.NUMERIC

The SQLServerDialect defines "Numeric(19,$l)" as default.
The scale is set by replacing $l with length from the mapping.
Maybe their could be a hint added in the documentation, about the meaning of length attribute for datatypes that are mapped to Numeric. At least for SQLServer and Sybase this seems to me to be a required attribute.

Maybe this helps anyone else.

Nils

Also for Oracle. I'll add a hint in the documentation, thought that this is obvious.