iSelfSchooling.com  Since 1999     References  |  Search more  | Oracle Syntax  | Free Online Oracle Training

    Home      .Services     Login       Start Learning     Certification      .                 .Share your BELIEF(s)...

 

. Online Accounting        .Copyright & User Agreement   |
    .Vision      .Biography     .Acknowledgement

.Contact Us      .Comments/Suggestions       Email2aFriend    |

 

PL/SQL I

Read Me First:

 

More Resources by Google:

IMPORTANT-READ CAREFULLY

 

In this tutorial, you will learn how to edit your SQL statement with different options.

 

As you noticed from your previous hands-on, if you made an error while typing a line of “SQL,” you had to use the “BACKSPACE” key to erase characters until you reached the mistake. However, this approach only worked if you were still on the same line in the “SQL” entry buffer.  Now, you are going to learn the “command line” and “notepad” editing techniques.

 

  • In the “command line” technique, you can type in the number corresponding to the line to be corrected.  Then you can type in the change, delete, or insert command to edit the SQL buffer.

  • If you don’t like “command line” editing, you can simply type edit, or “ed,” at the prompt in SQL*PLUS.  Oracle will immediately bring up your favorite text editor, perhaps notepad   You can change your text editor with the define_editor command.

 

Also in this Hands-On, we discuss PL/SQL blocks.

Before going through the Hands-On training, lets take note of the following important definitions to remember:

 

  • There are two categories of PL/SQL blocks: anonymous and named.

  • An anonymous block is a one time procedure and can not be referenced over and over.

  • A named block can be referenced as many times as you want.  Procedures, functions, packages and triggers are examples of named blocks.

  • A PL/SQL block contains “DECLARATION,” “BODY,” and “EXCEPTION” sections.

  • The “DECLARATION” section is the place where all PL/SQL variables, types, cursors, and user defined exceptions would be declared.

  • The “BODY” section contains the logical flow of your program instructions.

  • The “EXCEPTION” portion will handle certain types of predefined or user defined exceptions.  It handles predefined exceptions without explicitly coding error-handling routines in the procedure.  And it handles user defined exceptions when the exceptions are explicitly raised.

  • In your hands-on training, you will learn how to write code for each component a PL/SQL block.

  • An implicit cursor is a “SQL” statement that is executed in the “BODY” section of the PL/SQL block.  Remember it returns only one record and must have an “INTO” clause.

  • An explicit cursor is a named cursor that is defined in the “DECLARATION” section.  It will correspond to a defined SQL statement.  It can return as many records as you need.

  • In order to obtain data from a cursor, the cursor should be opened and fetched into a variable.  Then the cursor should be closed.

  • In the “BODY” section of the PL/SQL block, you can use conditional statement and process flow such as “if-then-else,” “simple loop,” “while-loop,” and “for-loop” statements.

  • The “FOR LOOP” statement handles the steps normally done in the open statement, and implicitly fetches data from the cursor until there is no row.  It also declares the cursor variable.  The “END LOOP” statement closes the cursor.

  • You can pass parameters to the cursor as input parameters.

 

You will see through out our tutorial, we may intentionally type a syntax error or perhaps a logical error to demonstrate to you how to solve them. Remember, you learn from your mistakes.  Learn how to face and patiently solve the problem, rather than get frustrated.   To build a fundamental and solid experience, you should build a habit of solving your problems with an abundance of patience.

 

Now, you should first read your case study, and try to solve the questions.  Then play the Hands-On training movie until you become familiar with the subject.  For more information about this subject, you are encouraged to read from a wide selection of available books.

 

Good luck!

 

Google
 
Web web site