I installed Oracle 11g. I didn't change the passwords for SYSTEM and SYS. However now I find that the default passwords do not work. Please help.
Default passwords of Oracle 11g?
oracle11g
Related Solutions
ODP.Net is the way to go as Microsoft has declared the .NET's Oracle implementation deprecated (see here: System.Data.OracleClient Namespace).
ODP.Net is a just another standard ADO.NET provider. Here is a tutorial here: Using Oracle Data Provider for .NET
Generally speaking a schema in oracle is the same as an user. Oracle Database automatically creates a schema when you create a user. A file with the DDL file extension is an SQL Data Definition Language file.
Creating new user (using SQL Plus)
Basic SQL Plus commands:
- connect: connects to a database
- disconnect: logs off but does not exit
- exit: exists
Open SQL Plus and log:
/ as sysdba
The sysdba is a role and is like "root" on unix or "Administrator" on Windows. It sees all, can do all. Internally, if you connect as sysdba, your schema name will appear to be SYS.
Create an user:
SQL> create user johny identified by 1234;
View all users and check if the user johny is there:
SQL> select username from dba_users;
If you try to login as johny now you would get an error:
ERROR:
ORA-01045: user JOHNY lacks CREATE SESSION privilege; logon denied
The user to login needs at least create session priviledge so we have to grant this privileges to the user:
SQL> grant create session to johny;
Now you are able to connect as the user johny:
username: johny
password: 1234
To get rid of the user you can drop it:
SQL> drop user johny;
That was basic example to show how to create an user. It might be more complex. Above we created an user whose objects are stored in the database default tablespace. To have database tidy we should place users objects to his own space (tablespace is an allocation of space in the database that can contain schema objects).
Show already created tablespaces:
SQL> select tablespace_name from dba_tablespaces;
Create tablespace:
SQL> create tablespace johny_tabspace
2 datafile 'johny_tabspace.dat'
3 size 10M autoextend on;
Create temporary tablespace (Temporaty tablespace is an allocation of space in the database that can contain transient data that persists only for the duration of a session. This transient data cannot be recovered after process or instance failure.):
SQL> create temporary tablespace johny_tabspace_temp
2 tempfile 'johny_tabspace_temp.dat'
3 size 5M autoextend on;
Create the user:
SQL> create user johny
2 identified by 1234
3 default tablespace johny_tabspace
4 temporary tablespace johny_tabspace_temp;
Grant some privileges:
SQL> grant create session to johny;
SQL> grant create table to johny;
SQL> grant unlimited tablespace to johny;
Login as johny and check what privileges he has:
SQL> select * from session_privs;
PRIVILEGE
----------------------------------------
CREATE SESSION
UNLIMITED TABLESPACE
CREATE TABLE
With create table privilege the user can create tables:
SQL> create table johny_table
2 (
3 id int not null,
4 text varchar2(1000),
5 primary key (id)
6 );
Insert data:
SQL> insert into johny_table (id, text)
2 values (1, 'This is some text.');
Select:
SQL> select * from johny_table;
ID TEXT
--------------------------
1 This is some text.
To get DDL data you can use DBMS_METADATA package that "provides a way for you to retrieve metadata from the database dictionary as XML or creation DDL and to submit the XML to re-create the object.". (with help from http://www.dba-oracle.com/oracle_tips_dbms_metadata.htm)
For table:
SQL> set pagesize 0
SQL> set long 90000
SQL> set feedback off
SQL> set echo off
SQL> SELECT DBMS_METADATA.GET_DDL('TABLE',u.table_name) FROM USER_TABLES u;
Result:
CREATE TABLE "JOHNY"."JOHNY_TABLE"
( "ID" NUMBER(*,0) NOT NULL ENABLE,
"TEXT" VARCHAR2(1000),
PRIMARY KEY ("ID")
USING INDEX PCTFREE 10 INITRANS 2 MAXTRANS 255
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DE
FAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "JOHNY_TABSPACE" ENABLE
) SEGMENT CREATION IMMEDIATE
PCTFREE 10 PCTUSED 40 INITRANS 1 MAXTRANS 255 NOCOMPRESS LOGGING
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DE
FAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "JOHNY_TABSPACE"
For index:
SQL> set pagesize 0
SQL> set long 90000
SQL> set feedback off
SQL> set echo off
SQL> SELECT DBMS_METADATA.GET_DDL('INDEX',u.index_name) FROM USER_INDEXES u;
Result:
CREATE UNIQUE INDEX "JOHNY"."SYS_C0013353" ON "JOHNY"."JOHNY_TABLE" ("ID")
PCTFREE 10 INITRANS 2 MAXTRANS 255
STORAGE(INITIAL 65536 NEXT 1048576 MINEXTENTS 1 MAXEXTENTS 2147483645
PCTINCREASE 0 FREELISTS 1 FREELIST GROUPS 1 BUFFER_POOL DEFAULT FLASH_CACHE DE
FAULT CELL_FLASH_CACHE DEFAULT)
TABLESPACE "JOHNY_TABSPACE"
More information:
DDL
DBMS_METADATA
- http://www.dba-oracle.com/t_1_dbms_metadata.htm
- http://docs.oracle.com/cd/E11882_01/appdev.112/e25788/d_metada.htm#ARPLS026
- http://docs.oracle.com/cd/B28359_01/server.111/b28310/general010.htm#ADMIN11562
Schema objects
Differences between schema and user
- https://dba.stackexchange.com/questions/37012/difference-between-database-vs-user-vs-schema
- Difference between a user and a schema in Oracle?
Privileges
Creating user/schema
- http://docs.oracle.com/cd/B19306_01/server.102/b14200/statements_8003.htm
- http://www.techonthenet.com/oracle/schemas/create_schema.php
Creating tablespace
SQL Plus commands
Best Answer
It is possible to connect to the database without specifying a password. Once you've done that you can then reset the passwords. I'm assuming that you've installed the database on your machine; if not you'll first need to connect to the machine the database is running on.
Ensure your user account is a member of the
dba
group. How you do this depends on what OS you are running.Enter
sqlplus / as sysdba
in a Command Prompt/shell/Terminal window as appropriate. This should log you in to the database as SYS.Once you're logged in, you can then enter
to reset the SYS password, and similarly for SYSTEM.
(Note: I haven't tried any of this on Oracle 12c; I'm assuming they haven't changed things since Oracle 11g.)