How to create a new database after initally installing oracle database 11g Express Edition?

When you installed XE.... it automatically created a database called "XE". You can use your login "system" and password that you set to login.

Key info

server: (you defined) port: 1521 database: XE username: system password: (you defined)

Also Oracle is being difficult and not telling you easily create another database. You have to use SQL or another tool to create more database besides "XE".

This link: Creating the Sample Database in Oracle 11g Release 2 is a good example of creating a sample database.

This link: Newbie Guide to Oracle 11g Database Common Problems should help you if you come across some common problems creating your database.

Best of luck!

EDIT: As you are using XE, you should have a DB already created, to connect using SQL*Plus and SQL Developer etc. the info is here: Connecting to Oracle Database Express Edition and Exploring It.

Extract:

Connecting to Oracle Database XE from SQL Developer SQL Developer is a client program with which you can access Oracle Database XE. With Oracle Database XE 11g Release 2 (11.2), you must use SQL Developer version 3.0. This section assumes that SQL Developer is installed on your system, and shows how to start it and connect to Oracle Database XE. If SQL Developer is not installed on your system, see Oracle Database SQL Developer User's Guide for installation instructions. Note: For the following procedure: The first time you start SQL Developer on your system, you must provide the full path to java.exe in step 1. For step 4, you need a user name and password. For step 6, you need a host name and port. To connect to Oracle Database XE from SQL Developer: Start SQL Developer. For instructions, see Oracle Database SQL Developer User's Guide. If this is the first time you have started SQL Developer on your system, you are prompted to enter the full path to java.exe (for example, C:\jdk1.5.0\bin\java.exe). Either type the full path after the prompt or browse to it, and then press the key Enter. The Oracle SQL Developer window opens. In the navigation frame of the window, click Connections. The Connections pane appears. In the Connections pane, click the icon New Connection. The New/Select Database Connection window opens. In the New/Select Database Connection window, type the appropriate values in the fields Connection Name, Username, and Password. For security, the password characters that you type appear as asterisks. Near the Password field is the check box Save Password. By default, it is deselected. Oracle recommends accepting the default. In the New/Select Database Connection window, click the tab Oracle. The Oracle pane appears. In the Oracle pane: For Connection Type, accept the default (Basic). For Role, accept the default. In the fields Hostname and Port, either accept the defaults or type the appropriate values. Select the option SID. In the SID field, type accept the default (xe). In the New/Select Database Connection window, click the button Test. The connection is tested. If the connection succeeds, the Status indicator changes from blank to Success. Description of the illustration success.gif If the test succeeded, click the button Connect. The New/Select Database Connection window closes. The Connections pane shows the connection whose name you entered in the Connection Name field in step 4. You are in the SQL Developer environment. To exit SQL Developer, select Exit from the File menu.

If you wish to create a new schema in XE, you need to create an USER and assign its privileges. Follow these steps:

Open the SQL*Plus Command-line

SQL> connect sys as sysdba

Enter the password

SQL> CREATE USER myschema IDENTIFIED BY Hga&dshja;
SQL> ALTER USER myschema QUOTA unlimited ON SYSTEM;
SQL> GRANT CREATE SESSION, CONNECT, RESOURCE, DBA TO myschema;
SQL> GRANT ALL PRIVILEGES TO myschema;

Now you can connect via Oracle SQL Developer and create your tables.

"How do I create an initial database ?"

You created a database when you installed XE. At some point the installation process prompted you to enter a password for the SYSTEM account. Use that to connect to the XE database using the SQL commandline on the application menu.

The XE documentation is online and pretty helpful. Find it here.

It's worth mentioning that 11g XE has several limitations, one of which is only one database per server. So using the pre-installed database is the sensible option.

Save the following code in a batch file (ex. createOraDbWin.bat). Change the parameter values like app_name, ora_dir etc., Run the file with administrative privileges. The batch file creates a basic oracle database:

Note : May take much time (say around 30mins)

REM ASSUMPTIONS
rem oracle xe has been installed
rem oracle_home has been set
rem oracle_sid has been set
rem oracle service is running

REM SET PARAMETERS
set char_set =al32utf8
set nls_char_set =al16utf16

set ora_dir=d:\app\db\oracle
set version=11.2.0.0
set app_name=xyz
set db_name=%app_name%_db
set db_sid=%db_name%_sid
set db_ins=%db_name%_ins
set sys_passwd=x3y5z7
set system_passwd=1x4y9z

set max_log_files=32
set max_log_members=4
set max_log_history=100
set max_data_files=254
set max_instances=1

set version_dir=%ora_dir%\%version%
set db_dir=%version_dir%\%db_name%

set instl_temp_dir=%db_dir%\instl\script

set system_dir=%db_dir%\system
set user_dir=%db_dir%\user
set undo_dir=%db_dir%\undo
set sys_aux_dir=%db_dir%\sysaux
set temp_dir=%db_dir%\temp
set control_dir=%db_dir%\control

set pfile_dir=%db_dir%\pfile
set data_dir=%db_dir%\data
set index_dir=%db_dir%\index
set log_dir=%db_dir%\log
set backup_dir=%db_dir%\backup
set archive_dir=%db_dir%\archive

set data_dir=%db_dir%\data
set index_dir=%db_dir%\index
set log_dir=%db_dir%\log
set backup_dir=%db_dir%\backup
set archive_dir=%db_dir%\archive
set undo_dir=%db_dir%\undo
set default_dir=%db_dir%\default

set system_tbs=%db_name%_system_tbs
set user_tbs=%db_name%_user_tbs
set sys_aux_tbs=%db_name%_sys_aux_tbs
set temp_tbs=%db_name%_temp_tbs
set control_tbs=%db_name%_control_tbs

set data_tbs=%db_name%_data_tbs
set index_tbs=%db_name%_index_tbs
set log_tbs=%db_name%_log_tbs
set backup_tbs=%db_name%_backup_tbs
set archive_tbs=%db_name%_archive_tbs
set undo_tbs=%db_name%_undo_tbs
set default_tbs=%db_name%_default_tbs

set system_file=%system_dir%\%db_name%_system.dbf
set user_file=%user_dir%\%db_name%_user.dbf
set sys_aux_file=%sys_aux_dir%\%db_name%_sys_aux.dbf
set temp_file=%temp_dir%\%db_name%_temp.dbf
set control_file=%control_dir%\%db_name%_control.dbf

set data_file=%data_dir%\%db_name%_data.dbf
set index_file=%index_dir%\%db_name%_index.dbf
set backup_file=%backup_dir%\%db_name%_backup.dbf
set archive_file=%archive_dir%\%db_name%_archive.dbf
set undo_file=%undo_dir%\%db_name%_undo.dbf
set default_file=%default_dir%\%db_name%_default.dbf

set log1_file=%log_dir%\%db_name%_log1.log
set log2_file=%log_dir%\%db_name%_log2.log
set log3_file=%log_dir%\%db_name%_log3.log

set init_file=%pfile_dir%\init%db_sid%.ora
set db_create_file=%instl_temp_dir%\createdb.sql
set db_drop_file=dropdb.sql

set db_create_log=%instl_temp_dir%\db_create.log
set db_drop_log=db_drop.log

set oracle_sid=%db_sid%

REM WRITE DROP DATABASE SQL COMMANDS TO FILE
echo shutdown immediate;>%db_drop_file%
echo startup mount exclusive restrict;>>%db_drop_file%
echo drop database;>>%db_drop_file%

REM EXECUTE DROP DATABASE SQL COMMANDS FROM THE FILE    
rem sqlplus -s "/as sysdba" @"%db_drop_file%">%db_drop_log%

REM DELETE WINDOWS ORACLE SERVICE
rem oradim -delete -sid %db_sid%

REM CREATE DIRECTORY STRUCTURE
md %system_dir%
md %user_dir%
md %sys_aux_dir%
md %temp_dir%
md %control_dir%

md %pfile_dir%
md %data_dir%
md %index_dir%
md %log_dir%
md %backup_dir%
md %archive_dir%
md %undo_dir%
md %default_dir%
md %instl_temp_dir%

REM WRITE INIT FILE PARAMETERS TO INIT FILE
echo db_name='%db_name%'>%init_file%
echo memory_target=1024m>>%init_file%
echo processes=150>>%init_file%
echo sessions=20>>%init_file%
echo audit_file_dest=%user_dir%>>%init_file%
echo audit_trail ='db'>>%init_file%
echo db_block_size=8192>>%init_file%
echo db_domain=''>>%init_file%
echo diagnostic_dest=%db_dir%>>%init_file%
echo dispatchers='(protocol=tcp) (service=%app_name%xdb)'>>%init_file%
echo shared_servers=4>>%init_file%
echo open_cursors=300>>%init_file%
echo remote_login_passwordfile='exclusive'>>%init_file%
echo undo_management=auto>>%init_file%
echo undo_tablespace='%undo_tbs%'>>%init_file%
echo control_files = ("%control_dir%\control1.ora", "%control_dir%\control2.ora")>>%init_file%
echo job_queue_processes=4>>%init_file%
echo db_recovery_file_dest_size = 10g>>%init_file%
echo db_recovery_file_dest=%log_dir%>>%init_file%
echo compatible ='11.2.0'>>%init_file%

REM WRITE DB CREATE AND ITS RELATED SQL COMMAND TO FILE    
echo startup nomount pfile='%init_file%';>>%db_create_file%
echo.>>%db_create_file%

echo create database %db_name%>>%db_create_file%
echo user sys identified by %sys_passwd%>>%db_create_file%
echo user system identified by %system_passwd%>>%db_create_file%
echo logfile group 1 ('%log1_file%') size 100m,>>%db_create_file%
echo group 2 ('%log2_file%') size 100m,>>%db_create_file%
echo group 3 ('%log3_file%') size 100m>>%db_create_file%
echo maxlogfiles %max_log_files%>>%db_create_file%
echo maxlogmembers %max_log_members%>>%db_create_file%
echo maxloghistory %max_log_history%>>%db_create_file%
echo maxdatafiles %max_data_files%>>%db_create_file%
echo character set %char_set %>>%db_create_file%
echo national character set %nls_char_set %>>%db_create_file%
echo extent management local>>%db_create_file%
echo datafile '%system_file%' size 325m reuse>>%db_create_file%
echo sysaux datafile '%sys_aux_file%' size 325m reuse>>%db_create_file%
echo default tablespace %default_tbs%>>%db_create_file%
echo datafile '%default_file%'>>%db_create_file%
echo size 500m reuse autoextend on maxsize unlimited>>%db_create_file%
echo default temporary tablespace %temp_tbs%>>%db_create_file%
echo tempfile '%temp_file%'>>%db_create_file%
echo size 20m reuse>>%db_create_file%
echo undo tablespace %undo_tbs%>>%db_create_file%
echo datafile '%undo_file%'>>%db_create_file%
echo size 200m reuse autoextend on maxsize unlimited;>>%db_create_file%
echo.>>%db_create_file%

echo @?\rdbms\admin\catalog.sql>>%db_create_file%
echo.>>%db_create_file%

echo @?\rdbms\admin\catproc.sql>>%db_create_file%
echo.>>%db_create_file%

echo create spfile from pfile='%init_file%';>>%db_create_file%
echo.>>%db_create_file%

echo shutdown immediate;>>%db_create_file%
echo.>>%db_create_file%

echo startup;>>%db_create_file%
echo.>>%db_create_file%

echo show parameter spfile;>>%db_create_file%
echo.>>%db_create_file%

REM CREATE WINDOWS ORACLE SERVICE
oradim -new -sid %db_sid% -startmode auto

REM EXECUTE DB CREATE SQL COMMANDS FROM FILE
sqlplus -s "/as sysdba" @"%db_create_file%">%db_create_log%

pause

Welcome your corrections and improvements!