Variable

A variable holds a value that can change.

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

Topics:

• Syntax

• Semantics

• Examples

• Related Topics

Syntax

variable_declaration ::=

Description of the illustration variable_declaration.gif

See:

• datatype ::=

• expression ::=

Semantics

variable_name

The name of the variable that you are declaring.

datatype

The data type of the variable that you are declaring.

Restriction on datatype If you use %ROWTYPE to declare a record variable, you cannot use the assignment operator (:=) or the keyword DEFAULT to assign its initial value. For information about %ROWTYPE, see "%ROWTYPE Attribute". For information about assigning values to records, see "Assignments to Records".

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 (see Table 3-10, "Possible Implicit PL/SQL Data Type Conversions").

Examples

• Example 2-7, "Variable Declarations"

• Example 2-9, "Variable and Constant Declarations with Initial Values"

• Example 2-10, "Variable Initialized to NULL by Default"

• Example 2-11, "Variable Declaration with NOT NULL Constraint"

Related Topics

In this chapter:

• "Assignment Statement"

• "Collection"

• "Constant"

• "Expression"

• "%ROWTYPE Attribute"

• "%TYPE Attribute"

In other chapters:

• "Variable Declarations"

• "Predefined PL/SQL Scalar Data Types and Subtypes"