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

Object types - syntax, Object Types An object type is a user-defined co...

Object Types An object type is a user-defined complex datatype which encapsulates the data structure along with the functions and procedures required to manipulate the data. Th

Theory of panspermia - origin of life, THEO R Y OF PANSPERMIA - Arrh...

THEO R Y OF PANSPERMIA - Arrhenius (1908) postulated the cosmic panspermia theory that claims that organisms existed throughout the universe, and their spores, etc., could

Use native dynamic sql - improve performance of application, Use Native Dyn...

Use Native Dynamic SQL A few programs (a normal-purpose report writer for illustration) should build and process a variety of SQL statements at run time. Therefore, their full

Authorize and fetch data from instagram, Authorize and fetch data from Inst...

Authorize and fetch data from Instagram Project Description: Incorporate Instagram feed on mobile site platform: c#, ms sql, jquerymobile, jquery Web admin Author

Difference between ttitle and btitle, TTITLE and BTITLE are commands in Pl-...

TTITLE and BTITLE are commands in Pl-SQL to control report headings and footers. This Ttitle & Btitle are mainly used on creating SQL*PLUS report. Ttitle is used for toptitle headi

Other monadic - sql, Other monadic - SQL In 2VL there are just 4 (2 2 ...

Other monadic - SQL In 2VL there are just 4 (2 2 ) monadic operators, of which negation is really the only "useful" one. When a third truth value is introduced we have 27 (3 3

Control structure, Control Structures The Control structures are the mo...

Control Structures The Control structures are the most important PL/SQL extension to the SQL. Not only does PL/SQL let you manipulate Oracle data, it lets you process the data

Rownum - sql pseudocolumns, ROWNUM The ROWNUM returns a number represe...

ROWNUM The ROWNUM returns a number representing the order in which a row was selected from the table. The first row selected has a ROWNUM of 1; the second row has a ROWNUM of

Between and not between operator in sql, BETWEEN and NOT BETWEEN Operator i...

BETWEEN and NOT BETWEEN Operator in SQL Example: Restricting exam marks to between 0 and 100 CREATE ASSERTION Marks_between_0_and_100 CHECK (NOT EXISTS (SELECT * FROM

Pl/sql expressions , Pl/SQL Expressions The Expressions are constructed...

Pl/SQL Expressions The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value

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