Oracle Live SQL - Can I add Tables to a schema after the table already exists?

[kevin Abel]

I asked a question a few minutes ago about how to create a schema.   While waiting for an answer  I used the DataBase Object Wizard to create 4 tables.  They do not belong to a schema.   Once I find out how to create a schema will I still be able to put the new tables into the schema?

[Tim Holloway]

They do belong to a schema. Every table and view and trigger, etc., etc. belongs to a schema. The question is which schema. Generally it's the default schema. for the database instance.

You can add, alter, and delete elements of a schema (including tables) at any time, although if there is software depending on existing schema definitions, it could potentially break. This, incidentally, is one reason why "SELECT * FROM…" syntax is discouraged.

[kevin Abel]

Tim,

I'm hoping that I will be able to use the Tables that I am creating with them belonging to the default schema.   Is there a prefix for the default schema?   Something like defalt.myTable    ?   Do I need the schema prefix?   I guess I will find out when I try.

[Tim Holloway]

Oridinarily you will not need to specify the schema and in fact, when using JDBC I believe that some DBMS's have support for a schema name in JDBC URLs. Note that I am talking generically, Your Mileage May Vary.

The default schema is conventionally named "default" as I recall. You do not need to include it as part of a table identification unless you are currently running out of some other schema.

As a general rule, you'll always be working with the default schema. Alternative schemas would be for exceptional situations where, perhaps a number of clients shared distinct sets of tables in a single database or you were prototyping a new or legacy version of a schema.

Finally, note that "schema" is both a specific database entity type (for databases that support them) and a generic description of the user-visible architecture of a database, Don't confuse the two.

Also, since things do vary, I'd recommend specifically looking in the Oracle documentation for their definition of "schema".

[kevin Abel]

Tim,

It has been a year and I did not thank you for this schema information.

Thanks,

Kevin