Handling variables in PL/SQL

Handling variables in PL/SQL:

• Declare and initialize variables in the declaration section.
• Declarations allocate storage space for a value according to its defined size.
• Declarations can be assigned with an Initial  value and can be imposed with a NOT NULL constraint or DEFAULT option.
• We reassign new values to variables in the executable section.
• Pass values into PL/SQL blocks through parameters.
• There are three parameter modes, they are IN(The default), OUT and IN OUT
• View results from a PL/SQL blocks through parameters.
• Reference variables can be used for Input or Output in SQL data manipulation statements.