Working with packages v15

A package is a named collection of functions, procedures, variables, cursors, user-defined record types, and records that are referenced using a common qualifier: the package identifier. Packages have the following characteristics:

  • They provide a convenient means of organizing the functions and procedures that perform a related purpose. Permission to use the package functions and procedures depends on one privilege granted to the entire package. You must reference all of the package programs with a common name.
  • You can declare certain functions, procedures, variables, types, and so on in the package as public. Public entities are visible and other programs that are given EXECUTE privilege on the package can reference them. For public functions and procedures, only their signatures are visible: the program names, parameters, if any, and return types of functions. The SPL code of these functions and procedures isn't accessible to others. Therefore applications that use a package depend on only the information available in the signature and not in the procedural logic itself.
  • You can declare other functions, procedures, variables, types, and so on in the package as private. Private entities can be referenced and used by function and procedures in the package but not by other external applications. Private entities are for use only by programs in the package.
  • Function and procedure names can be overloaded in a package. You can define one or more functions/procedures with the same name but with different signatures. This capability enables you to create identically named programs that perform the same job but on different types of input.

package_components creating_packages referencing_a_package using_packages_with_user_defined_types dropping_a_package

Package components

Describes the two main components of packages

Viewing packages and package body definition

Describes how to view the package specification and package body definition

Creating packages

Describes how to create the package specification

Referencing a package

Describes how to reference the types, items, and subprograms that are declared in a package specification

Using packages with user-defined types

Provides an example that incorporates various user-defined types in the context of a package

Dropping a package

Defines the syntax for dropping a package