Which exception is rose when there is no other clause in the 'WHEN' clause of a CASE statement, and none of the choices in the 'WHEN' clause have been selected?

PL/SQL is Oracle Corporation's procedural extension for SQL and the Oracle relational database. PL/SQL is available in Oracle Database, Times Ten in-memory database, and IBM Db2. Oracle Corporation usually extends PL/SQL functionality with each successive release of the Oracle Database.

PL/SQL vs SQL: SQL is a non-procedural language that executes a single query at a time whereas, PL/SQL is a procedural language and executes blocks of code at once which helps reduce traffic and increases processing speed.