SQL :: Information Schema Views

You can select the structure of your schema (tables, columns, ...etc.) in most DBs

for example SQL using what is called Information Schema Views

SELECT * FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE='BASE TABLE'

and oracle uses:

SELECT owner, table_name
  FROM dba_tables

or

SELECT owner, table_name
  FROM all_tables
or
SELECT table_name
  FROM user_tables
good luck :)