Pl/SQL Expressions
The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value to an expression. An illustration of a simple arithmetic expression is shown below:
-X / 2 + 3
The Unary operators like the negation operator (-) operate on one operand; the binary operators like the division operator (/) operate on two operands. The PL/SQL has no ternary operators.
The simplest expressions consist of a single variable that yields a value directly. The PL/SQL evaluates (finds the present value of) an expression by combining the values of the operands in ways specify by the operators. This forever yields a single value and datatype. The PL/SQL determines the datatype by examining the expression and the context in which it appear.