Using prior and next - collection method, PL-SQL Programming

Assignment Help:

Using PRIOR and NEXT

The PRIOR(n) returns the index number that precede index n in a collection. The NEXT(n) returns the index number which succeed the index n. If n has no predecessor, then the PRIOR(n) returns NULL. Similarly, if n has no successor, then NEXT(n) returns NULL. The PRIOR and NEXT do not wrap from one end of a collection to another. For illustration, the statement below assigns a NULL to n as the first element in a collection has no predecessor:

n := courses.PRIOR(courses.FIRST); -- assigns NULL to n

The PRIOR is the inverse of NEXT. For illustration, if element i exists, the statement below assigns element i to itself:

projects(i) := projects.PRIOR(projects.NEXT(i));

You can use PRIOR or NEXT to traverse the collections indexed by any sequence of subscripts. In the example below, you use NEXT to traverse a nested table from that some elements have been deleted:

i := courses.FIRST; -- get subscript of first element

WHILE i IS NOT NULL LOOP

-- do something with courses(i)

i := courses.NEXT(i); -- get subscript of next element

END LOOP;


Related Discussions:- Using prior and next - collection method

Organic evolution, Organi c Evolution Evolution is a slow continuou...

Organi c Evolution Evolution is a slow continuous, irreversible and natural process of change to give rise to advance and diverse forms of life i.e. formation of new specie

Using host arrays - bulk bind performance improvement, Using Host Arrays ...

Using Host Arrays The Client-side programs can use anonymous PL/SQL blocks to bulk-bind input and output host arrays. However, this is the well-organized way to pass the colle

Updating objects in pl sql, Updating Objects: To change the attributes...

Updating Objects: To change the attributes of objects in an object table, you can use the UPDATE statement, as the illustration below shows: BEGIN UPDATE persons p SET p

Recursion versus iteration, Recursion versus Iteration Dissimilar the i...

Recursion versus Iteration Dissimilar the iteration, recursion is not crucial to PL/SQL programming. Any problem which can be solved using recursion can be solving using the it

Custom ms access database designed, I would like to have a custom MS Access...

I would like to have a custom MS Access database designed and coded that would help me schedule my customer's orders and that would help me track my employees production output and

Primary key, PRIMARY KEY: PRIMARY KEY  indicates that the table is sub...

PRIMARY KEY: PRIMARY KEY  indicates that the table is subject to a key constraint, in this case declaring that no two rows in the table assigned to ENROLMENT can ever have the

Sql queries, SELECT a.child_fname,a.child_lname,concat(b.parent_title,b.par...

SELECT a.child_fname,a.child_lname,concat(b.parent_title,b.parent_fname), b.parent_lname,b.parent_tphone FROM child a,parent b WHERE a.parent_id=b.parent_id ORDER BY a.child_fnam

Block structure in pl/sql, Block Structure The PL/SQL is a block-struct...

Block Structure The PL/SQL is a block-structured language. That is, the fundamental units (procedures, anonymous blocks, and functions) that make up a PL/SQL program are logi

Semidifference and not - sql, Semidifference and NOT - SQL In this sec...

Semidifference and NOT - SQL In this section first describe the relational difference operator, named MINUS. Example here shows SQL's closest counterpart of that operator.

Using prior and next - collection method, Using PRIOR and NEXT The PRI...

Using PRIOR and NEXT The PRIOR(n) returns the index number that precede index n in a collection. The NEXT(n) returns the index number which succeed the index n. If n has no pr

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