How to create a "facade" table?

Posted by tputkonen on Stack Overflow See other posts from Stack Overflow or by tputkonen
Published on 2010-03-25T12:00:26Z Indexed on 2010/03/25 12:03 UTC
Read the original article Hit count: 369

Filed under:

mysql

|

jpa

|

database-design

A legacy database contains a join table which links tables table1 and table2, and contains just two foreign keys:

TABLE_ORIG:
table1_id
table2_id

In order to utilize this table using JPA I would need to create a surrogate primary key to the link table. However, the existing table must not be modified at all.

I would like to create another table which would contain also a primary key in addition to the foreign keys:

TABLE_NEW:
id
table1_id
table2_id

All changes to TABLE_ORIG should be reflected in TABLE_NEW, and vice versa.

Is this doable in mysql?

© Stack Overflow or respective owner

Related posts about mysql

How to remove MySQL completely with config and library files on ubuntu 12.04 gnome 3.0

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I tried everything till now: sudo apt-get remove mysql-server mysql-client mysql-common sudo apt-get purge mysql-server mysql-client mysql-common sudo apt-get autoremove and even more commands... But whenever I am trying to locate mysql. I get a no. of files related to mysql command: shell>>… >>> More
mysql: Cannot load from mysql.proc. The table is probably corrupted

as seen on Server Fault - Search for 'Server Fault'
Mysql was started: /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 but when I'm trying to do something: ERROR 1548 (HY000) at line 1: Cannot… >>> More
Why is there a /etc/init.d/mysql file on this Slackware machine? How could it have gotten there?

as seen on Server Fault - Search for 'Server Fault'
A client of my IT-consulting service owns a web-development shop. He's been having problems with a Slackware 12.0 server running MySQL 5.0.67. The machine was set up by the client's sysadmin, who left on bad terms. My client no longer employs a sysadmin. As far as I can tell, the only copy of MySQL… >>> More
mysql: Bind on unix socket: Permission denied

as seen on Server Fault - Search for 'Server Fault'
Can't start mysql with: sudo /usr/bin/mysqld_safe --datadir=/srv/mysql/myDB --log-error=/srv/mysql/logs/mysqld-myDB.log --pid-file=/srv/mysql/pids/mysqld-myDB.pid --user=mysql --socket=/srv/mysql/sockets/mysql-myDB.sock --port=3700 120222 13:40:48 mysqld_safe Starting mysqld daemon with databases… >>> More
MySQL – Learning MySQL Online in 6 Hours – MySQL Fundamentals in 320 Minutes

as seen on SQL Authority - Search for 'SQL Authority'
MySQL is one of the most popular database language and I have been recently working with it a lot. Data have no barrier and every database have their own place. I have been working with MySQL for quite a while and just like SQL Server, I often find lots of people asking me if I have a tutorial which… >>> More

Related posts about jpa

Detach an entity from a JPA persistence context (JPA 2.0 / Hibernate / EJB 3 / J2EE 6)

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I wrote a stateless EJB method allowing to get an entity in "read-only" mode. The way to do this is to get the entity with the EntityManager then detach it (using the JPA 2.0 EntityManager). My code is the following: @PersistenceContext private EntityManager entityManager; public T getEntity(int… >>> More
AndroMDA maven code generation and JPA Annotations

as seen on Stack Overflow - Search for 'Stack Overflow'
I am using the AndroMDA plugin for maven to generate code from an uml diagram made in MagicDraw. When the code is generated, AndroMDA desings the JPA annotation for the persitence layer. I think that at the compilation process AndroMDA uses Naming Strategies to determine the Table and Column names… >>> More
How to populate Java (web) application with initial data using Spring/JPA/Hibernate

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to setup my database with initial data programmatically. I want to populate my database for development runs, not for testing runs (it's easy). The product is built on top of Spring and JPA/Hibernate. Developer checks out the project Developer runs command/script to setup database with initial… >>> More
Eclipselink problem in a javase project

as seen on Stack Overflow - Search for 'Stack Overflow'
I am getting this error when I am running my eclipselink project. [EL Warning]: 2008.12.05 11:47:08.056--java.lang.NoClassDefFoundError: org/jboss/resource/adapter/jdbc/ValidConnectionChecker was thrown on attempt of PersistenceLoadProcessor to load class com.mysql.jdbc.integration.jboss.MysqlValidConnectionChecker… >>> More
JPA thinks I'm deleting a detached object

as seen on Stack Overflow - Search for 'Stack Overflow'
So, I've got a DAO that I used to load and save my domain objects using JPA. I finally managed to get the transaction stuff working (with a bunch of help from the folks here...), now I've got another issue. In my test case, I call my DAO to load a domain object with a given id, check that it got… >>> More