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SecondaryTable Mapping

Anup Om
Ranch Hand

Joined: Dec 30, 2009
Posts: 62
Hello Everybody,

I am trying to map following tables to a single class User. Is my mapping alright? Nowhere I specify that user_roles has a composite primary key. Will this work?




create table users (
user_name varchar(15) not null primary key,
user_pass varchar(15) not null
);

create table user_roles (
user_name varchar(15) not null,
role_name varchar(15) not null,
primary key (user_name, role_name)
);







Thanks,

SCJP6
James Sutherland
Ranch Hand

Joined: Oct 01, 2007
Posts: 553
It will work if the user_name is unique in the role table.

If a user has multiple roles as the schema allows, then it may work for some situations, but is not a very good idea. A OneToMany to Role would be better.

TopLink : EclipseLink : Book:Java Persistence : Blog:Java Persistence Performance
Anup Om
Ranch Hand

Joined: Dec 30, 2009
Posts: 62
Thank you so much. I understand better now. Secondary table mapping may be used for table if they have same primary key.
 
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subject: SecondaryTable Mapping