Hi
We have been successfully using hibernate in our app for several years and it works just great. However, I have a question about mapping files and join tables.
We have a table for USERS and a table for FUNCTIONS. We store the functions available to a user in a APP_FUNCTIONS table. We do this because we have standard extra fields (ROW_VERSION, STATUS, CREATED_BY) that all tables share. We do not physically delete records but set STATUS to 'D' which means that we can't use the USER ID and FUNCTION ID to form the natural primary key.
Across the application, we have tended to create an object to reflect the APP_FUNCTION and have a mapping file which reflects this. This means that our Java object graph also has the join table embedded in it and we also have to maintain the extra mapping file.
So yesterday, I found we could almost achieve what we needed by inserting this to our user mapping file
Code:
<set name="userFunctions" table="USER_FUNCTION">
<key column="USER_ID" />
<composite-element class="UserFunction" >
<many-to-one name="function"
column="FUNCTION_ID"
not-null="true"
class="Function" lazy="false"/>
<property name="createdBy" type="java.lang.String" column="CREATED_BY" not-null="true" length="20" />
<property name="createdTs" type="java.sql.Timestamp" column="CREATED_TS" not-null="true" length="11" />
<property name="rowStatus" type="java.lang.String" column="ROW_STATUS" not-null="true" length="1" />
</composite-element>
</set>
This so very nearly works ! It means that I have a list of userFunctions in my User object and I can get straight from that to my function. It also eliminates the need for that extra mapping file. To me, the composite element looks nearly like an embedded mapping file.
Except that I can't see how to do the following with this construct
1. Make it support an <id> element. I'd like to add new associations from my application and I'd like to point it at our sequence generation implementation when we a new UserFunction to the user.
2. Make it support <version> for when we do updates. We use this across the application. It is fantastic and drives large amounts of very important synchronisation code.
3. Make it support <sql-delete>. As I mentioned, we never physically delete but intercept the deletion with this and simply set the row_status field to 'D'.
Any ideas ? Thanks all.
Chris
Hibernate version:3.2.5 Name and version of the database you are using:SybaseCode:
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