Understanding nested tables, PL-SQL Programming

Assignment Help:

Understanding Nested Tables

Within the database, the nested tables can be considered as one-column database tables. The Oracle stores the rows of a nested table in no specific order. But, when you retrieve the nested table into the PL/SQL variable, the rows are given consecutive subscripts starting at 1. That provides you array-like access to the individual rows.

Within PL/SQL, the nested tables are like one-dimensional arrays. Though, nested tables differ from arrays in two significant ways. Firstly, the arrays have a fixed upper bound, but nested tables are unbounded .Therefore, the size of a nested table can increase dynamically.

 

150_Understanding Nested Tables.jpg

                                   Figure: Array versus Nested Table


Secondly, the arrays should be dense (having consecutive subscripts). Therefore, you cannot delete individual elements from an array. Initially, the nested tables are dense, but they can be sparse (having nonconsecutive subscripts). And hence, you can delete elements from a nested table using the built-in procedure DELETE. That might leave gaps in the index, but the built-in function NEXT iterate over any series of subscripts.


Related Discussions:- Understanding nested tables

Some varray examples-manipulating collections, Some Varray Examples In S...

Some Varray Examples In SQL Plus, assume that you define an object type Project, as described below: SQL> CREATE TYPE Project AS OBJECT ( 2 project_no NUMBER(2), 3 title VARCHA

Oracle PL SQL, I need to write one function and one procedure to query a Or...

I need to write one function and one procedure to query a Oracle 10.1 DB using PL SQL. I have the schema and exact queries...along with work Ive started and a template to put the a

Using not null-declarations in sql, Using NOT NULL Besides assigning an ...

Using NOT NULL Besides assigning an initial value, the declarations can impose the NOT NULL constraint, as the example below shows: acct_id INTEGER(4) NOT NULL := 9999; You ca

Semidifference via except and join - sql, Semidifference via EXCEPT and JOI...

Semidifference via EXCEPT and JOIN - SQL SELECT * FROM (SELECT StudentId FROM IS_CALLED WHERE Name = 'Devinder' EXCEPT DISTINCT CORRESPONDING SELECT StudentId

Using operator value in pl sql, Using Operator VALUE: As you may expec...

Using Operator VALUE: As you may expect, the operator VALUE returns the value of an object. The VALUE takes its argument a correlation variable.  For illustration, to return a

Change sql file into csv for product registration, Change Sql file into CSV...

Change Sql file into CSV for product registration on Magento Project Description: I have a set of files that are in Sql format and could like for a developer to help me with

What is a record, What Is a Record  ? A record is a group of related...

What Is a Record  ? A record is a group of related data items that stored in the fields, each with its own name and datatype. Assume that you have different data about an em

Cursor variables in pl sql, Cursor Variables:   To execute the multi-...

Cursor Variables:   To execute the multi-row query, the Oracle opens an unnamed work region that stores the processing information. You can use an explicit cursor that names

Example of not exists operator - sql, Example of NOT EXISTS Operator - SQL ...

Example of NOT EXISTS Operator - SQL Example is a translation into SQL of the corresponding example, which is included there merely to show that for any scalar comparison the

Data types in sql - integer, Data Types in SQL - Integer INTEGER or  s...

Data Types in SQL - Integer INTEGER or  synonymously INT, for integers within a certain range. SQL additionally has types SMALLINT and BIGINT for certain ranges of integers. T

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd