How do you declare and use PL/SQL collections? Give an example.

In PL/SQL (Procedural Language/Structured Query Language), collections provide a powerful way to store and manipulate multiple values within a single variable. PL/SQL offers several types of collections, including nested tables, associative arrays (also known as index-by tables), and varrays (variable-size arrays). Here is an in-depth explanation of how to declare and use PL/SQL collections, along with an example: 1. Declaring PL/SQL Collections: * To declare a PL/SQL collection, you need to specify the collection type and optionally its size or limit. * Collection types can be declared at the schema level, package level, or within a PL/SQL block. * The syntax for declaring PL/SQL collections is as follows: ``` sql`DECLARE collection_name collection_type;` ``` * Here, `collection_name` is the name of the collection variable, and `collection_type` represents the specific collection type being declared. 2. Using PL/SQL Collections: * Once a collection is de....