asked on

hibernate <list>

hi guys

I have a hibernate question and i need some clarification

I have two tables PROJECT and PROJECT_USERS . A Project has multiple users so i am using one-to-many relationship in my hbm.xml file below

<class name="hibernate.entity.Project" table="PROJECT" catalog="eProject">
<list name="projectUserses" table="PROJECT_USERS" inverse="true" lazy="false" fetch="select">
<key column="PROJECT_ID" not-null="true" />
<list-index column="USER_ID" />
<one-to-many class="hibernate.entity.ProjectUsers" />
</list>
</class>

My table structure is
PROJECT table
PROJECT_ID (PK)
Name

PROJECT_USERS table
PROJECT_ID (PK)
USER_ID (PK)
Role

Users table
USER_ID (PK)
Fname
Lname

So based on the scenario above is my <list> definition above correct? specifically are these two lines correct ?

<key column="PROJECT_ID" not-null="true" /> --> Is this column PROJECT_ID the primary key column of PROJECT table?

<list-index column="USER_ID" /> Is this column USER_ID the primary key column for PROJECT_USERS table?

Am i moving correctly?

Any help appreciated

thanks

sweetfa2

http://www.vaannila.com/hibernate/hibernate-example/hibernate-mapping-many-to-many-1.html

Jay Roy

ASKER

whats that link?It has got nothing to do with my question.

Anyone who can answer my question will be greatly appreciated.
Thanks.

Mick Barry

thats actually a many to many.
Did you specifically want a List?
And did you need the role property? You'll need an extra entity if you do.

Jay Roy

ASKER

>>>Did you specifically want a List?
Yes
>>And did you need the role property? You'll need an extra entity if you do
yeah, i have three entities
Project.java/ project.hbm.xml
Users.java/user.hbm.xml
ProjectUsers/projectUser.hbm.xml

But the list which i defined above
<list name="projectUserses" table="PROJECT_USERS" inverse="true" lazy="false" fetch="select">
<key column="PROJECT_ID" not-null="true" />
<list-index column="USER_ID" />
<one-to-many class="hibernate.entity.ProjectUsers" />
</list>
is throwing error

i am searching by projectId 227565 (corresponding to hibernate.entity.Project)
and getting this error on the list definition

[4/21/11 15:32:13:463 EDT] 00000017 SystemErr R org.hibernate.exception.DataException: could not initialize a collection: [hibernate.entity.Project.projectUserses#227565]
at org.hibernate.exception.SQLStateConverter.convert(SQLStateConverter.java:100)
at org.hibernate.exception.JDBCExceptionHelper.convert(JDBCExceptionHelper.java:66)
...
....
Caused by: java.sql.SQLException: The value supplied cannot be converted to INTEGER. at net.sourceforge.jtds.jdbc.Support.convert(Support.java:653)
at net.sourceforge.jtds.jdbc.JtdsResultSet.getInt(JtdsResultSet.java:641)
at net.sourceforge.jtds.jdbc.JtdsResultSet.getInt(JtdsResultSet.java:968)

thanks for response and any help appreciated.

Jay Roy

ASKER

<list name="projectUserses" table="PROJECT_USERS" inverse="true" lazy="false" fetch="select">
<key column="PROJECT_ID" not-null="true" />
<list-index column="USER_ID" />
<one-to-many class="hibernate.entity.ProjectUsers" />
</list>

when i replace the above list with set, it works fine. so i am really thinking
<list-index column="USER_ID" /> is the suspect.

Mick Barry

well it doesn't really make sense to use an is as a list index, you don't actually have a list index in the database

Jay Roy

ASKER

List index in a database? Can you explain a little more?
Thx

ASKER CERTIFIED SOLUTION

Mick Barry

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