In SQL: :my_var In PL/SQL: V('my_var') or NV('my_var') In text: &my_var
Here is what the above code is Doing:
1. The first line is a comment. It’s ignored by the computer.
2. The second line is a variable declaration. It tells the computer that we want to use a variable named “my_var” in our code.
3. The third line is a variable assignment. It tells the computer to assign the value “Hello World” to the variable “my_var”.
4. The fourth line is a variable substitution. It tells the computer to replace the variable “my_var” with its value, “Hello World”.