Basic Syntax of a PL/SQL program is:
<declarations section>
BEGIN
<executable section>
EXCEPTION
<exception handling section>
END;
My 'First PL/SQL' Program:
v_message varchar2(20):= 'My first PLSQL program!';
BEGIN
dbms_output.put_line(v_message);
END;
/
Identifiers
PL/SQL identifiers are constants, variables, exceptions, procedures, cursors, and reserved words. The identifiers consist of a letter optionally followed by more letters, numerals, dollar signs, underscores, and number signs and should not exceed 30 characters.
By default, identifiers are not case-sensitive. So you can use integer or INTEGER to represent a numeric value. You cannot use a reserved keyword as an identifier.
Delimiters
List of PL/SQL delimiters:
| Delimiter | Description |
|---|---|
| +, -, *, / | Addition, subtraction/negation, multiplication, division |
| % | Attribute indicator |
| ' | Character string delimiter |
| . | Component selector |
| (,) | Expression or list delimiter |
| : | Host variable indicator |
| , | Item separator |
| " | Quoted identifier delimiter |
| = | Relational operator |
| @ | Remote access indicator |
| ; | Statement terminator |
| := | Assignment operator |
| => | Association operator |
| || | Concatenation operator |
| ** | Exponentiation operator |
| <<, >> | Label delimiter (begin and end) |
| /*, */ | Multi-line comment delimiter (begin and end) |
| -- | Single-line comment indicator |
| .. | Range operator |
| <, >, <=, >= | Relational operators |
| <>, '=, ~=, ^= | Different versions of NOT EQUAL |
Comments
There are single-line and multi-line comments available in PL/SQL.
-- variable declaration
v_message varchar2(20):= 'My first PLSQL example!';
BEGIN
/*
* This is PL/SQL executable statement(s)
*/
dbms_output.put_line(message);
END;
/
