Re: basic browsing commands for oracle...

Well the Suggestion of Sybrand is true that you should not try to play with Oracle without reading the manuals , but in addition I am let you know that how you can see the information of cuurent instance running , and what database is running

First of all If you have installed the Oracle Enterprise Edition Server , then during installstion Oracle Installer might asked you that you want to create a starter database, if you have chosed that option to yes then you might have the starter database. The Oracle database are not like Mysql database actually one oracle Database stand for one like a Server(just for example, ther could be more database on a server) if you compare it with mysql. Now the Oracle have schemas in comparison mysql databases, when ever you want to select(called connect in Oracle) Database(called schema in Oracle) you just have to issue the following command on sql Propmpt

connect user_name/password

IF you want to start the sqlplus it will ask you t, to which schema you want to connect , you specify the Oracle Practice schema called Scott, and the default password of "scott" is "tiger". there is also a third tab in the sqlplus connect dailog box, leave that tab empt(in your case and if you haev installed your database on your local machine).

Now we come to the Oracle database. Note that Oracle database is diferent from the schema , in a way that One oracle database can have many Schemas(which you called the database in mysql).

Now if you want to see that how to select the instance runnig , try this

Select * from V$instance.

this query return the instance name.

To know that what oracle instance is , this is a long story that cannot be expalin in one page. so read Oracle Online help which come with oracle enterprise edition, to me you do not need to buy any thing else.

 Now I should compare mysql with Oracle , you have default database named "mysql", which contain the information about the whole databases. So oracle has data dictionaries views to see that type of information, but those are in thousands of number.:))

Now if you know that mysql does not enforce the referential integrity, Oracle do enforce that referential Integrity.

As far sql commands are concrened, oracle support all those feature that are supported by mysql plus many other , one main feature that I know mysq does not support os the subqueries, but oracle do support that subquiries, and oracle also suppor the that select satement in the form caluses that is not support in mysql, there are many more :))

SO to have a complete idea of what Oracle is , you should read the Oracle on line help manuall which come with oracle CD. that will helps you a lot.

Faheem

In article <3A31D9E7.B704A3B1_at_phatmorton.com>,   Nathan Affleck <n8_at_phatmorton.com> wrote:
> Completely new to Oracle and wish to "browse" around the databases
> currently installed....
>
> I am a little familiar with mysql and have used commands like
 mysqlshow
> to show the current running databases. Is there something familiar in
> Oracle. How do you find out what databases and instances that are
> running?
>
> How do you then select those databases or instances, to further issues
> commands. For instance, in mysql, I am use to using the "use
> databasename" command, where I could then execute "show tables;" then
> maybe simple SELECT statements on those tables.
>
> Simply, using sqlplus how do I know what databases are installed, and
> how do I show them, select, them, then further show tables within that
> database to execute SELECT or whatever statements.
>
> If you haven't noticed already, I'm confused...
>
> Thanks for any help.
>
> ..n8
>

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Before you buy. Received on Sat Dec 09 2000 - 07:59:33 CST