Oracle dual table: what is dual table in oracle

Oracle dual table

Oracle dual table is a table automatically created by oracle database along with the data dictionary. DUAL is in the schema of the user SYS but is accessible by the name DUAL to all users.

Why dual oracle table is required

In oracle, SELECT statement requires FROM clause, which fetches data from oracle table. But in some scenarios, we have constant values which is not available in any table and we need to refer to these values in our SQL queries as additional value. To use these we require SQL DUAL table.

select lower('I AM AN ANALYST') from dual;

In the above example, we wanted to use a constant value ‘I AM AN ANALYST’ in a small … Continue Reading