How to declare and initialize Variables in PL/SQL

1.	How to declare and initialize Variables in PL/SQL
Answer» PL/SQL allocates memory for the variable's value when a variable is declared. The storage location is IDENTIFIED by the variable name. Declaration The following is the syntax: variable_name [CONSTANT] datatype [NOT NULL] [:= \| DEFAULT initial_value] Here, variable_name: Name of the variable datatype: The datatype Example for a string variable: name varchar2(15); Let us see an example for a number precision limit. This is called CONSTRAINT declaration that needs less memory: a number(5, 2) Initialization To INITIALIZE a variable, you can use the DEFAULT keyword as well as the assignment operator. Let us see them one by one. Initialization with DEFAULT keyword: DECLARE msg varchar2(15) DEFAULT 'House'; BEGIN dbms_output.put_line(msg); END; / The output: House Initialization with assignment operator: DECLARE DEVICE varchar2(11) := 'Laptop'; BEGIN dbms_output.put_line(device); END; / The output: Laptop

Answer»

PL/SQL allocates memory for the variable's value when a variable is declared. The storage location is IDENTIFIED by the variable name.

Declaration

The following is the syntax:

variable_name [CONSTANT] datatype [NOT NULL] [:= | DEFAULT initial_value]

Here,

Example for a string variable:

name varchar2(15);

Let us see an example for a number precision limit. This is called CONSTRAINT declaration that needs less memory:

a number(5, 2)

Initialization

To INITIALIZE a variable, you can use the DEFAULT keyword as well as the assignment operator. Let us see them one by one.

Initialization with DEFAULT keyword:

DECLARE msg varchar2(15) DEFAULT 'House'; BEGIN dbms_output.put_line(msg); END; /

The output:

House

Initialization with assignment operator:

DECLARE DEVICE varchar2(11) := 'Laptop'; BEGIN dbms_output.put_line(device); END; /

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