Looking for a Tutor Near You?

Post Learning Requirement »
x

Choose Country Code

x

Direction

x

Ask a Question

x

x
x
For better view click here
x
Hire a Tutor
DISCOVER

ORACLE PLSQL - PL SQL - Basic Syntax

Loading...

Published in: Oracle Training
1,078 Views

This document provides information about Basic Syntax of PL/SQL, Identifiers and  Delimeters.

Debarun S / Kolkata

10 years of teaching experience

Qualification: B.Tech

Teaches: Computer, Mathematics, Science, Chemistry, Computer Science, Physics, School Level Computer, Defence Exams, IBPS, Insurance Exams, SSC Exams

Contact this Tutor
  1. In this chapter, we will discuss the Basic Syntax of PL/SQL which is a block-structured language; this means that the PL/SQL programs are divided and written in logical blocks of code. Each block consists of three sub-parts S.N0 Declarations 1 Sections & Description This section starts with the keyword DECLARE. It is an optional section and defines all variables, cursors, subprograms, and other elements to be used in the program. Executable Commands This section is enclosed between the keywords BEGIN and END and it is a mandatory 2 section. It consists of the executable PL/SQL statements of the program. It should have at least one executable line of code, which may be just a NULL command to indicate that nothing should be executed. Exception Handling 3 This section starts with the keyword EXCEPTION. This optional section contains exception(s) that handle errors in the program. Every PL/SQL statement ends with a semicolon (;). PL/SQL blocks can be nested within other PL/SQL blocks using BEGIN and END. Following is the basic structure of a PL/SQL block DECLARE BEGIN EXCEPTION END; The 'Hello World' Example DECLARE Hello, World! message varchar2 (20) BEGIN dbms output. put line (message) END; The end; line signals the end of the PL/SQL block. To run the code from the SQL command line, you may need to type / at the beginning of the first blank line after the last line of the code. When the above code is executed at the SQL prompt, it produces the following result Hello World P L/ SQL procedure successfully completed.
  2. The PL/SQL 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. The PL/SQL Delimiters A delimiter is a symbol with a special meaning. Following is the list of delimiters in PL/SQL 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 The PL/SQL Comments
  3. Program comments are explanatory statements that can be included in the PL/SQL code that you write and helps anyone reading its source code. All programming languages allow some form of comments. The PL/SQL supports single-line and multi-line comments. All characters available inside any comment are ignored by the PL/SQL compiler. The PL/SQL single-line comments start with the delimiter -- (double hyphen) and multi-line comments are enclosed by / * and */. DECLARE variable declaration Hello, World! message varchar2 (20) BEGIN * P L/ SQL executable statement (s) dbms output. put line (message) END; When the above code is executed at the SQL prompt, it produces the following result Hello World P L/ SQL procedure successfully completed. PL/SQL Program Units A PL/SQL unit is any one of the following PL/SQL block Function Package Package body Procedure Trigger Type Type body Each of these units will be discussed in the following chapters.

Need a Tutor or Coaching Class?

Post an enquiry and get instant responses from qualified and experienced tutors.

Post Requirement

Related Study Notes

Upload Study Notes

If you have your own Study Notes which you think can benefit others, please upload on LearnPick. For each approved Study Note you will get 100 Credit Points and 100 Activity Score which will increase your profile visibility.

Upload Now
Home > Study Notes > ORACLE PLSQL - PL SQL - Basic Syntax