GrassField

Hi,

This is to share the screenshot of the oracle installation in my mandriva 2009 (Free). The installation is very simple. Download the oracle installation jar from oracle.com. It has only one dependency, considering mandriva 2009, which is libaio.jar. See whether it is coming with Mandriva, or else download from the web. thats it. then install the RPMs.

Once RPMs are installed, database need to be configured. Issue the following command to configure the database.

/etc/init.d/oracle-xe configure

This will take you to a text wizard asking the system username, password etc and complete your installation process. See the screenshot below.

Thats all!

Try to login to your oracle server with the web interface
http://localhost:8080/apex
ofcourse you have the option to change the port also.

happy dbing!

I was not able to start my oracle instance today. The start and stop server scripts dint show any error, instead they said server started/stopped without any problem. Windows System event log had a error entry saying “The OracleXETNSListener service terminated unexpectedly. It has done this 8 time(s).”when I run lsnrctl start I found the issue.D:\Documents and Settings\pandian> lsnrctl startLSNRCTL for 32-bit Windows: Version 10.2.0.1.0 - Production on 23-NOV-2008 01:08:40Copyright (c) 1991, 2005, Oracle. All rights reserved.Starting tnslsnr: please wait...TNSLSNR for 32-bit Windows: Version 10.2.0.1.0 - ProductionSystem parameter file is D:\oraclexe\app\oracle\product\10.2.0\server\network\admin\listener.oraLog messages written to D:\oraclexe\app\oracle\product\10.2.0\server\network\log\listener.logListening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(PIPENAME=\\.\pipe\EXTPROC_FOR_XEipc)))Error listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=TCP)(HOST=acs-59abc34f442)(PORT=1521)))TNS-12545: Connect failed because target host or object does not existTNS-12560: TNS:protocol adapter errorTNS-00515: Connect failed because target host or object does not exist32-bit Windows Error: 1001: Unknown errorListener failed to start. See the error message(s) above...There is the issue. I renamed my host name. So listener is not able to start. I edited the listener.ora found at oraclexe\app\oracle\product\10.2.0\server\NETWORK\ADMIN folder. I changed the host to localhost. It is working now!

DB legends are releasing their edition as a miniature, previously MS-SQL came with their own mini server. MySQL is always small doing great jobs. and Here I am giving Oracle 10g Express edition. It is cool, very easy to install and get it running. Add to its great things, It offers a cool web interface (see the screenshot below), like Linux admin tools . Oracle says it is free to develop, deploy, and distribute. Those who are interested can get their copies at

http://www.oracle.com/technology/products/database/xe/index.html

This post is regarding auto increment in oracle. Usually I used to add AUTO_INCREMENT flag in mysql. But it is not a single word task oracle. we need to create sequence and trigger to do the same. please see the following examples 1. Here is my table structure.

CREATE TABLE FEED_DETAIL
(
FEED_ID NUMBER(6, 0),
FEED_TEXT VARCHAR2(128 BYTE),
FEED_TITLE VARCHAR2(128 BYTE),
FEED_TYPE VARCHAR2(12 BYTE),
XML_URL VARCHAR2(128 BYTE),
HTML_URL VARCHAR2(128 BYTE)
)
2. lets play with FEED_ID now. lets make it auto increment. create a sequence now

create sequence FEED_DETAIL_SEQUENCE
start with 1
increment by 1
nomaxvalue;

A sequence is an object in Oracle that is used to generate a number sequence. This can be useful when you need to create a unique number to act as a primary key.

3. Now create a trigger. A database trigger is procedural code that is automatically executed in response to certain events on a particular table in a database. Triggers can restrict access to specific data, perform logging, or audit data modifications.

create or replace trigger FEED_DETAIL_TRIGGER
before insert on FEED_DETAIL
for each row
begin
select FEED_DETAIL_SEQUENCE.nextval into :new.feed_id from dual;
end;

Now insert the values

insert into feed_detail (feed_text, feed_title, feed_type, xml_url, html_url) values('a', 'b', 'c', 'd', 'e');
insert into feed_detail (feed_text, feed_title, feed_type, xml_url, html_url) values('a', 'b', 'c', 'd', 'e');

Enjoy auto incrementing column now!

As I have told you in my previous post, I was trying to read from a table within a loop. I am opening a new connection, new statement and firing the query to get the resultset. It was working fine for a few records, finally it dies with this exception

java.sql.SQLException: ORA-01000: maximum open cursors exceeded

Alas, I forgot to close the resultset!!