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Scalar Variable Declaration

A scalar variable stores a value with no internal components. The value can change.

A scalar variable declaration specifies the name and data type of the variable and allocates storage for it. The declaration can also assign an initial value and impose the NOT NULL constraint.

You reference a scalar variable by its name.

Topics:

• Syntax

• Semantics

• Examples

• Related Topics

Syntax

variable_declaration ::=

Description of the illustration variable_declaration.gif

See "expression ::=".

Semantics

variable_name

The name of the variable that you are declaring.

datatype

The name of a scalar data type, including any qualifiers for size, precision, and character or byte semantics. For information about scalar data types, see Chapter 3, "PL/SQL Data Types".

NOT NULL

Imposes the NOT NULL constraint on the variable. For information about this constraint, see "NOT NULL Constraint".

expression

The value to be assigned to the variable when the declaration is elaborated. The value of expression must be of a data type that is compatible with the data type of the variable.

Examples

• Example 2-9, "Scalar Variable Declarations"

• Example 2-11, "Variable and Constant Declarations with Initial Values"

• Example 2-12, "Variable Initialized to NULL by Default"

• Example 2-13, "Variable Declaration with NOT NULL Constraint"

Related Topics

In this chapter:

• "Assignment Statement"

• "Collection Variable"

• "Constant Declaration"

• "Expression"

• "Record Variable Declaration"

• "%ROWTYPE Attribute"

• "%TYPE Attribute"

In other chapters:

• "Variable Declarations"

• Chapter 3, "PL/SQL Data Types"