Summary


In this chapter, you learned that

  • PL/SQL (Procedural Language/SQL) is built on top of SQL and is a third generation programming language.

  • PL/SQL programs are divided up into blocks with each block containing PL/SQL and SQL statements.

  • You may use a loop, such as a WHILE or FOR loop, to run one or more statements multiple times.

  • You use a cursor when you have a SELECT statement that returns more than one row from the database. You retrieve the rows into the cursor using your SELECT statement and then fetch the rows from the cursor.

  • Exceptions are used to handle errors that occur in your PL/SQL code.

  • A procedure contains a group of SQL and PL/SQL statements. Procedures allow you to centralize your business logic in the database and may be used by any program that accesses the database.

  • A function is similar to a procedure except that a function must return a value to the statement from which it is called.

  • You can group procedures and functions together into packages, which allow you to encapsulate related functionality into one self-contained unit. Packages are typically made up of two components : a specification and a body.

A trigger is a procedure that is run automatically by the database when a specified SQL DML INSERT , UPDATE, or DELETE statement is run against a specified database table. Triggers are useful for doing things like advanced auditing of changes made to column values in a table.

In the next chapter, you ll learn about database objects.




Oracle Database 10g SQL
Oracle Database 10g SQL (Osborne ORACLE Press Series)
ISBN: 0072229810
EAN: 2147483647
Year: 2004
Pages: 217

flylib.com © 2008-2017.
If you may any questions please contact us: flylib@qtcs.net