Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Using the Collection Methods
The collection methods below help to generalize the code and make collections easier to use and also make your applications easier to maintain:
EXISTS
COUNT
LIMIT
FIRST and LAST
PRIOR and NEXT
EXTEND
TRIM
DELETE
A collection method is a built-in function or the process that operates on collections and is called using the dot notation. The syntax is as shown below:
collection_name.method_name[(parameters)]
The Collection methods can be called from the procedural statements but not from the SQL statements. The COUNT, EXISTS, LIMIT, FIRST, PRIOR, LAST, & NEXT are the functions, that appear as a part of an expression. And EXTEND, DELETE, and TRIM are the procedures that appear as a statement. Also, the EXISTS, TRIM, PRIOR, NEXT, EXTEND, and DELETE take parameters. Each parameter should be an integer expression. Only the EXISTS can be applied to automatically null collections. Whenever you apply another method to such type of collections, then the PL/SQL raises COLLECTION_IS_NULL.
Example of ADD CONSTRAINT in SQL Example: Alternative formulation for MAX_ENROLMENTS ALTER TABLE IS_ENROLLED_ON ADD CONSTRAINT MAX_ENROLMENTS CHECK ((SELECT COUNT (*)
Using ROLLBACK The ROLLBACK statements end the present transaction and undo any change made during the transaction. The Rolling back is helpful for two reasons. Firstly, if yo
Dynamic Ranges The PL/SQL lets you determine the loop range dynamically at run time, as the example below shows: SELECT COUNT(empno) INTO emp_count FROM emp; FOR i IN 1..emp_cou
Consider the schema for FreeChecking Bank, that we designed given below. Translate the given ER schema into SQL CREATE TABLE statements (indicating primary key, unique and foreign
what are ER diagrams
UNION without CORRESPONDING - SQL The use of UNION without CORRESPONDING. Example is merely by omitting CORRESPONDING, but only because the operands have identical SELECT clau
Entering and Exiting If you enter the executable part of an autonomous routine, the major transaction suspends. When you exit the routine, the major transaction resumes. To ex
Using Operator DEREF: You cannot navigate through refs within the PL/SQL procedural statements. Rather than, you should use the operator DEREF in the SQL statement. The DEREF
Question: (a) The objective of query optimization is to choose the most efficient strategy for implementing a given relational query, thereby improving the system performance. On
Accessing Attributes: You can refer to an attribute only by its name not by its position in the object type. To access or modify the value of an attribute, you can use the dot
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd