PostgreSQL Adapter

PostgreSQL Adapter for NexJ

Project Goal

Develope an adapter to enable NexJ Express model to interact with PostgreSQL database

Current Status

Dec 2010
Database 'test' is created in Postgre. sample table 'mutex' is created for testing the connection properties. No need for SET SQL mode in Postgre Creating tables in process Tables are created. Creating indexes and triggers in process

Nov 2010

Walk through parts of code related to SQLadapter, SqlSchemaManger and setup scripts in NexJ Express code SQLAdapter (src, test) and SQLSchemaManager (src, test) classes are extended to create PostgreSQL classes Proper PostgreSQL Driver is installed. Postgre package url for XADataSource is added to the related files. cofig and connection files are modified based on Postgre properties Application is now connected to the Postgre database.

Project Phases

Phase 1: Investigation

• Get requirements from NexJ (Meeting on Friday Nov 5th)
• Walk-through the code
• Familiarization with PostgreSQL

Phase 2: Connect to PostgreSQL

• Create Test Environment

Phase 3: Test first design

• 1- Create a PostgreSQL database through some scripts

Through the process in postgresql_setup.sql, the database was created, initialized and tested:

A database called 'test is created in PostgreSQL : CREATE DATABASE test

To create a user along with password: CREATE USER test WITH PASSWORD 'test';

Login to the database 'test' with username 'test': psql -U test test

Create a Schema called 'test' inside the database 'test' with particular owner 'test': CREATE SCHEMA test AUTHORIZATION test;

Create a table called 'Mutex' with primary key: CREATE TABLE test.Mutex(id INT PRIMARY KEY);

Insert a value into the primary key: INSERT INTO test.Mutex(id) VALUES (1);

• 3- Working inside Schema 'test'

CREATE TABLE test.xxx

data types are changed in appendColumnType() in PostgreSQLSchemaManager.java based on each jdbc type's equivalent in PostgreSQL.

The implementation in crateTextTable in file PostgreSQLSchemaManager.java is removed for now (base class's version is being called).

CREATE INDEX test.xxx

CREATE Trigger test.xxx // if it's needed for PostgreSQL as well as MySQL

Phase 2: Coding

• List of Tasks

1. implementation of PostgreSQLAdapter.java
2. implementation of PostgreSQLAdapterTest.java
3. implementation of PostgreSQLSchemaManager.java
4. implementation of main.upgrade

Resources

• Intro

Concept of Adapter [1]

FOSSLC PostgreSQL

• Java
• Database & Persistence
• JDBC
• PostgreSQL Specifications
• MySQL Specifications
• Postgre - MySQL Compare