how to extract tables attributes like column name , datatype ,nullable for all the tables from the database from oracle pl/sql

Question

Is there any query that can be used to retrive the Tables and its column attributes like column name , datatype, nullable etc for all the tables inside the database

For Oracle Pl/SQL

Answer 1

The Oracle SQL you need would be the following (run as user 'SYS'):

select owner, table_name, column_name, data_type, nullable
from dba_tab_columns;

If you do a desc dba_tab_columns you will get a list of many more columns which may be of interest to you as part of your result set.
You can use a SQL tool (i.e. SQL*Plus) to run this query or you can use PL/SQL to call this query and put the results in PL/SQL variables then print them out via DBMS_OUTPUT.PUT_LINE().

HTH