NexJ Express Connecting to PostgreSQL

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Revision as of 21:38, 9 December 2010 by Minooz (talk | contribs) (2- Create a PostgreSQL database through some scripts)
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PostgreSQL Adapter for NexJ - Create Test Environment

1- Setup the postgresql-connection

For testing the connection, the 'PostgreSQLAdapterTest.java' is being used.

- TODOs

- Files to Modify

- STEPS for Connection

Installed the JDBC3 Postgresql Driver, Version 9.0-801 and added it to the libraries in JDK
The driver class which is being used for NexJ Express Model is: org.postgresql.xa.PGXADataSource
The driver is loaded from RelationalDatabaseFragment.java and RelationalDatabase.java
Metadata is loaded from the particular driver
   /* MySQLAdapterTest.java */
      try
      {
         s_metadata = loadMetadata(ADAPTER_NAME);
      }

   /* SQLDataTest.java */
   protected static Metadata loadMetadata(String sAdapter)
   {
      Properties props = SysUtil.getConfigProperties();  // sets DEFAULT_CONFIG_URL = '/' + NAMESPACE + "/default.config"
      props = new Properties(props);
      props.setProperty(XMLMetadataLoader.CONNECTIONS_URL_PROPERTY, "/nexj/" + sAdapter.toLowerCase(Locale.ENGLISH) + ".connections");  // sets the properties to postgresql.connection
After all properties are loaded, it creates the connection through Connection Factory files.

- Modifications

2- 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- Creating Schema

CREATE TABLE test.xxx
data types are changed in appendColumnType() in PostgreSQLSchemaManager.java based on each jdbc type's equivalent in PostgreSQL.
crateTextTable in
The implementation in CREATE INDEX test.xxx in file PostgreSQLSchemaManager.java is removed for now (base class's version is being called).
CREATE Trigger test.xxx // if it's needed for PostgreSQL as well as MySQL