Usage of nested tables in package

To temporarily store query data within Oracle packages, you can use PL/SQL collections such as associative arrays, nested tables, or VARRAYs. Here is an example using nested tables:

1. Create the Package Specification:

CREATE OR REPLACE PACKAGE temp_data_pkg AS
    TYPE temp_table_type IS TABLE OF source_table%ROWTYPE;
    PROCEDURE populate_temp_table;
    PROCEDURE process_temp_table;
END temp_data_pkg;

2. Create the Package Body:

CREATE OR REPLACE PACKAGE BODY temp_data_pkg AS
    temp_table temp_table_type;

    PROCEDURE populate_temp_table AS
    BEGIN
        -- Initialize the collection
        temp_table := temp_table_type();

        -- Populate the collection with data from the query
        SELECT * BULK COLLECT INTO temp_table
        FROM source_table
        WHERE some_condition;
    END populate_temp_table;

    PROCEDURE process_temp_table AS
    BEGIN
        -- Process each row in the collection
        FOR i IN 1 .. temp_table.COUNT LOOP
            DBMS_OUTPUT.PUT_LINE('ID: ' || temp_table(i).id || ', Name: ' || temp_table(i).name);
        END LOOP;
    END process_temp_table;
END temp_data_pkg;

3. Execute the Procedures from the Package:

BEGIN
    temp_data_pkg.populate_temp_table;
    temp_data_pkg.process_temp_table;
END;

In this example:

• A nested table type temp_table_type is defined in the package specification to store rows from the source_table.
• The populate_temp_table procedure populates the nested table with data using the BULK COLLECT clause.
• The process_temp_table procedure processes each row in the nested table.
• The nested table temp_table is declared in the package body to store the temporary data.

This approach allows you to temporarily store and process query data within an Oracle package without creating a physical temporary table.