Procedures vs. Packages oracle
2010-09-10 15:32:47| 分类：
Packages are groups of procedures, functions, variables, and SQL statements grouped together
into a single unit. To execute a procedure within a package, you must first list the package name,
and then list the procedure name, as shown in the following example:
execute BOOK_INVENTORY.NEW_BOOK('ONCE REMOVED');
Here, the NEW_BOOK procedure within the BOOK_INVENTORY package was executed.
Packages allow multiple procedures to use the same variables and cursors. Procedures within
packages may be either available to the public (as is the NEW_BOOK procedure in the prior example)
or private, in which case they are only accessible via commands from within the package (such
as calls from other procedures). Examples of packages are shown in “create package Syntax,” later
in this chapter.
Packages may also include commands that are to be executed each time the package is called,
regardless of the procedure or function called within the package. Thus, packages not only group
procedures but also give you the ability to execute commands that are not procedure specific.
See “Initializing Packages,” later in this chapter, for an example of code that is executed each
time a package is called.