Diksha IT Training Centre

  Dual Table in Oracle and its uses in Database. Hello Everyone, Today we will discuss about Dual table in Oracle and it’s benefit in Database.Dual table in Oracle which is a special and dynamic table used for evaluating expressions or calling functions. Once you Install Oracle Database in your System Dual table is available in all schema’s . The DUAL table contains one column named DUMMY whose data type is VARCHAR2() and contains one row with a value X. The DUAL table is most simple one because it was designed for fast access and can be used for any calculation checking date and printing any value as the output for our  requirement. To  Access Dual table we can use Select statement. To see the output from Dual table we can use below select statement and can see output as column DUMMY with one Row value X. Select *  from dual; By using the DUAL table, we can execute queries that contain functions that do not involve any table like the UPPER() function as below: SELECT   U