How to create new schema and list all schema name in oracle - oracle

I want to create one new schema in oracle and I used sample code, which is available here
CREATE SCHEMA AUTHORIZATION oe
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY, quantity NUMBER)
CREATE VIEW new_product_view
AS SELECT color, quantity FROM new_product WHERE color = 'RED'
GRANT select ON new_product_view TO scott
/
But, getting error
ERROR at line 1:
ORA-02421: missing or invalid schema authorization identifier
Also, Please help me how to list name of all available schema. I am using
select username from dba_users;
to list schema, but i think, its not a right approach, because, user and schema has many-to-many relation,which means I can't get all schema name here.
Please help me !!

From oracle documentation:
This statement does not actually create a schema. Oracle Database
automatically creates a schema when you create a user
So you first need to create a User with the schema name
As for your query it's fine, since username list is equal to schema names unavailable
UPDATE: I can't really test it now, but should be something like this:
CREATE USER oe IDENTIFIED BY oePSWRD;
CREATE SCHEMA AUTHORIZATION oe
CREATE TABLE new_product
(color VARCHAR2(10) PRIMARY KEY, quantity NUMBER)
CREATE VIEW new_product_view
AS SELECT color, quantity FROM new_product WHERE color = 'RED'
GRANT select ON new_product_view TO scott;

From the docs: http://docs.oracle.com/cd/B28359_01/server.111/b28286/statements_6014.htm
The schema name must be the same as your Oracle Database username.
Do you want to find all users, or all users for which a table (for example) exists? If the latter then ...
select distinct
owner
from
dba_tables
where
owner not in ('SYS','SYSTEM')
Add in other usernames that you're not interested in listing as required.

Related

Using oracle seq generator in Informatica Mapping [duplicate]

I use SQL developer and i made a connection to my database with the system user, after I created a user and made a another connection with that user with all needed privileges.
But when I try to proceed following I get the SQL Error
ORA-00942 table or view does not exist.:
INSERT INTO customer (c_id,name,surname) VALUES ('1','Micheal','Jackson')
Because this post is the top one found on stackoverflow when searching for "ORA-00942: table or view does not exist insert", I want to mention another possible cause of this error (at least in Oracle 12c): a table uses a sequence to set a default value and the user executing the insert query does not have select privilege on the sequence. This was my problem and it took me an unnecessarily long time to figure it out.
To reproduce the problem, execute the following SQL as user1:
create sequence seq_customer_id;
create table customer (
c_id number(10) default seq_customer_id.nextval primary key,
name varchar(100) not null,
surname varchar(100) not null
);
grant select, insert, update, delete on customer to user2;
Then, execute this insert statement as user2:
insert into user1.customer (name,surname) values ('michael','jackson');
The result will be "ORA-00942: table or view does not exist" even though user2 does have insert and select privileges on user1.customer table and is correctly prefixing the table with the schema owner name. To avoid the problem, you must grant select privilege on the sequence:
grant select on seq_customer_id to user2;
Either the user doesn't have privileges needed to see the table, the table doesn't exist or you are running the query in the wrong schema
Does the table exist?
select owner,
object_name
from dba_objects
where object_name = any ('CUSTOMER','customer');
What privileges did you grant?
grant select, insert on customer to user;
Are you running the query against the owner from the first query?
Case sensitive Tables (table names created with double-quotes) can throw this same error as well. See this answer for more information.
Simply wrap the table in double quotes:
INSERT INTO "customer" (c_id,name,surname) VALUES ('1','Micheal','Jackson')
You cannot directly access the table with the name 'customer'. Either it should be 'user1.customer' or create a synonym 'customer' for user2 pointing to 'user1.customer'. hope this helps..
Here is an answer: http://www.dba-oracle.com/concepts/synonyms.htm
An Oracle synonym basically allows you to create a pointer to an object that exists somewhere else. You need Oracle synonyms because when you are logged into Oracle, it looks for all objects you are querying in your schema (account). If they are not there, it will give you an error telling you that they do not exist.
I am using Oracle Database and i had same problem. Eventually i found ORACLE DB is converting all the metadata (table/sp/view/trigger) in upper case.
And i was trying how i wrote table name (myTempTable) in sql whereas it expect how it store table name in databsae (MYTEMPTABLE). Also same applicable on column name.
It is quite common problem with developer whoever used sql and now jumped into ORACLE DB.
in my case when i used asp.net core app i had a mistake in my sql query. If your database contains many schemas, you have to write schema_name before table_name, like:
Select * from SCHEMA_NAME.TABLE_NAME...
i hope it will helpful.

ORA-00942: Table or View not exist connecting with another user

in Oracle SQL developer I got error ORA-00942: Table or View not exist connecting with another user when I do the following:
CREATE USER marta IDENTIFIED BY 'marta';
GRANT SELECT, INSERT ON myTable TO marta;
so then, executing:
CONNECT marta/marta;
INSERT INTO myTable VALUES ('1', 'foo', bar');
got the ORA-00942...
Obviusly, If I use system user I can insert row with no issues.
I searched other answers but I couldnt solve this... what is wrong
Obviusly, If I use system user I can insert row with no issues.
Uh-oh. There's nothing obvious about that. The SYSTEM user should not own a table called MY_TABLE (or whatever application table that is actually named). The SYSTEM user is part of the Oracle database, its schema is governed by Oracle and using it for our own application objects is really bad practice.
But it seems you have created a table in that schema and user MARTA can't see it. That's standard. By default users can only see their own objects. They can only see objects in other schemas if the object's owner (or a power user) grants privileges on that object to the other user.
So, as SYSTEM
grant select on my_table to marta;
Then, as MARTA
select * from system.my_table;
To avoid prefixing the owning schema MARTA can create a synonym:
create or replace synonym my_table for system.my_table;
select * from my_table;
But really, you need to stop using SYSTEM for your own tables.

Oracle does not allow to create "USER" table

Oracle is not allowing to create USER table.
Can anyone guide me to create USER table in Oracle.?
TIA.
Can you use a different name like my_user or something else. If you are insistent about using the table name user then you will have to provide the table name in quotes.
CREATE TABLE "USER"
(
col1 NUMBER(10)
)
You, will have to use quotes and maintain the upper case when doing any operations on this table.
The following will give you an error.
select * from USER;
ORA-00903: invalid table name
However, the following will work.
select * from "USER";
That said I don't recommend this option and it would be good if you can change your table name.
USER is a reserved keyword in oracle. Thus it can't be used directly.
Here is the list of restricted keywords a.k.a reserved words.
e.g. you can't either create a table called TABLE...

Oracle Create Table without Insert permission

Is it possible in oracle dbms for a user to have the permission to create a table but not have the permission to insert in it although the same user just created it?
Thank you in advance!
Short answer:
No, it's not.
Longer answer:
You can do pretty much anything you want. If you want to restrict insert access the usual method would be to create the table in a different schema. Assuming you have a table emp in the schema hr, which you wanted to access from the schema 'users`:
You would grant users permission to SELECT from the table emp when connected as hr:
grant select on emp to users
or, if you also want users to be able to UPDATE emp:
grant select, update on emp to users
Lastly, when connected as users, you prefix the table name with the schema it is located in:
select * from hr.emps
You can now select from the table but not insert into it.

Schema, User and functional Id in Oracle

I confused lot in oracle about schema, user and functional id. Let consider my two different cases
Case I :
Let us consider SCOTT#ORCL.If we think SCOTT is user. while creating user alone it ll create a schema. Correct me If i am wrong. In this case while we were creating SCOTT user alone SCOTT schema was created. Suppose If we create another schema say X . Is this possible to SCOTT user owns X schema ?
Case II :
Let us consider SCOTT#ORCL.If we think SCOTT is schema alone i-e which is created by schema command alone. If it is so then what is the use of schema w/o any user who is going to own it.
I heard oracle function ID is one which will connect several user/schema(i don't know whether I can put schema/user here ) in a data base. is there is difference b/w oracle functional ID with user/schema ?
Many people find this topic confusing, because we tend to bandy around USER and SCHEMA interchangeably, when they are in fact separate if related entities.
A schema is the collection of database objects owned by a user. When we create a user we create their schema at the same time. Initially their schema is empty.
It is easy to demonstrate that USER and SCHEMA are distinct, because we change the current schema in the session. This just means we can reference objects in another user's schema without prefixing them with the owner's name.
SQL> desc t1
Name Null? Type
----------------------------------------- -------- -------------
ID NUMBER
SQL> alter session set current_schema=APC
2 /
Session altered.
SQL> desc t1
ERROR:
ORA-04043: object t1 does not exist
SQL> sho user
USER is "X"
SQL>
In this case, either APC doesn't have a table called T1 or he hasn't granted it to X. The only way X can see her own table is to prefix it with her own name, or switch the current schema back to herself.
To answer your first question, the schema always has the same name as the user. So it is not possible for SCOTT to own schema X; schema X is owned by user X.
To answer your second question, it is impossible to create a schema without a user.
True, there is a CREATE SCHEMA command, but this requires the prior creation of the user. It is actually not creating a schema but creating several database objects. In effect it is more of a ADD OBJECTS TO SCHEMA command.
SQL> conn sys as sysdba
Enter password:
Connected.
SQL> create user x identified by x
2 default tablespace users quota 10m on users
3 /
User created.
SQL> grant create session, create table to x
2 /
Grant succeeded.
SQL> conn x/x
Connected.
SQL> create schema authorization x
2 create table t1 (id number)
3 create table t2 (id number)
4 /
Schema created.
SQL> select table_name from user_tables
2 /
TABLE_NAME
------------------------------
T1
T2
SQL>
The CREATE SCHEMA command is pretty limited: we can create tables, views and indexes, and grant privileges on objects. The advantage of it is simply that we can create several objects in a single transaction, so that all the creates are rolled back if one fails. This is not possible when we run each create statement separately.
Not sure what you're thinking off when you mention "function ID". It's not a standard piece of Oracle functionality.
This does not define the difference between an owner and schema.
But I have always struggled with the idea that I create N number of users....when I want each of these users to "consume" (aka, use) a single schema.
This guy shows how to do this (have N number of users...get "redirected" to a single schema.
I will paste his code as well, on the off-chance the URL link dies in the future.
http://www.oracle-base.com/articles/misc/schema-owners-and-application-users.php
He has a second "synonym" approach. But I am only pasting the CURRENT_SCHEMA version.
AGAIN, I take NO credit for this. I just hate when someone says "your answer is at this link" and BOOM, the link is dead. :<
......................................................
(from http://www.oracle-base.com/articles/misc/schema-owners-and-application-users.php)
CURRENT_SCHEMA Approach
This method uses the CURRENT_SCHEMA session attribute to automatically point application users to the correct schema.
First, we create the schema owner and an application user.
CONN sys/password AS SYSDBA
-- Remove existing users and roles with the same names.
DROP USER schema_owner CASCADE;
DROP USER app_user CASCADE;
DROP ROLE schema_rw_role;
DROP ROLE schema_ro_role;
-- Schema owner.
CREATE USER schema_owner IDENTIFIED BY password
DEFAULT TABLESPACE users
TEMPORARY TABLESPACE temp
QUOTA UNLIMITED ON users;
GRANT CONNECT, CREATE TABLE TO schema_owner;
-- Application user.
CREATE USER app_user IDENTIFIED BY password
DEFAULT TABLESPACE users
TEMPORARY TABLESPACE temp;
GRANT CONNECT TO app_user;
Notice that the application user can connect, but does not have any tablespace quotas or privileges to create objects.
Next, we create some roles to allow read-write and read-only access.
CREATE ROLE schema_rw_role;
CREATE ROLE schema_ro_role;
We want to give our application user read-write access to the schema objects, so we grant the relevant role.
GRANT schema_rw_role TO app_user;
We need to make sure the application user has its default schema pointing to the schema owner, so we create an AFTER LOGON trigger to do this for us.
CREATE OR REPLACE TRIGGER app_user.after_logon_trg
AFTER LOGON ON app_user.SCHEMA
BEGIN
DBMS_APPLICATION_INFO.set_module(USER, 'Initialized');
EXECUTE IMMEDIATE 'ALTER SESSION SET current_schema=SCHEMA_OWNER';
END;
/
Now we are ready to create an object in the schema owner.
CONN schema_owner/password
CREATE TABLE test_tab (
id NUMBER,
description VARCHAR2(50),
CONSTRAINT test_tab_pk PRIMARY KEY (id)
);
GRANT SELECT ON test_tab TO schema_ro_role;
GRANT SELECT, INSERT, UPDATE, DELETE ON test_tab TO schema_rw_role;
Notice how the privileges are granted to the relevant roles. Without this, the objects would not be visible to the application user. We now have a functioning schema owner and application user.
SQL> CONN app_user/password
Connected.
SQL> DESC test_tab
Name Null? Type
----------------------------------------------------- -------- ------------------------------------
ID NOT NULL NUMBER
DESCRIPTION VARCHAR2(50)
SQL>
This method is ideal where the application user is simply an alternative entry point to the main schema, requiring no objects of its own.

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