Lexical unit in PL/SQL

Lexical unit can be classified as

---

• Delimiters
• Identifiers
• Literals
• Comments

Delimiters in PL/SQL

---

Symbol	Meaning
+	addition operator
%	attribute indicator
‘	character string delimiter
.	component selector
/	division operator
(	expression or list delimiter
)	expression or list delimiter
:	host variable indicator
,	item separator
*	multiplication operator
“	quoted identifier delimiter
=	relational operator
<	relational operator
>	relational operator
@	remote access indicator
;	statement terminator
–	subtraction/negation operator
:=	assignment operator
=>	association operator
||	concatenation operator
**	exponentiation operator
<<	label delimiter (begin)
>>	label delimiter (end)
/*	multi-line comment delimiter (begin)
*/	multi-line comment delimiter (end)
..	range operator
<>	relational operator
!=	relational operator
~=	relational operator
^=	relational operator
<=	relational operator
>=	relational operator
—	single-line comment indicator

 

Identifier in PL/SQL

---

PL/SQL is not case sensitive with respect to identifies

v_first_name

v_perc

V_LAST_NAME

 

Literal in PL/SQL

---

Alex, 428, True,

 

Comments in PL/SQL

---

Single line comment

Prefix single-line comments with two hyphens (–).

Example:

-- This is Simple Procedure
Create or Replace procedure test
IS
BEGIN
dbms_output.put_line('Hi This is Bhavesh Lakhani');
END test;

Multi line comment

Place multiple-line comments between the symbols /* and */

DECLARE
v_annual_salary NUMBER (9,2);
BEGIN
/*

Compute the annual salary based on the
monthly salary input from the user

*/
v_annual_salary:= monthly_salary * 12;
--The following line displays the annual salary DBMS_OUTPUT.PUT_LINE(v_annual_sal);
END;