Cursor for loops, PL-SQL Programming

Assignment Help:

Cursor FOR Loops

In most cases that need an explicit cursor, you can simplify the coding by using a cursor FOR loop rather of the OPEN, FETCH, and CLOSE statements. A cursor FOR loop implicitly declares its loop index as a record that shows a row fetched from the database. Then, it opens a cursor, repeatedly fetches rows of values from the result set into fields in the record, and after that closes the cursor when all rows have been processed. In the example below, the cursor FOR loop implicitly declares emp_rec as a record:

DECLARE

CURSOR c1 IS

SELECT ename, sal, hiredate, deptno FROM emp;

... BEGIN

FOR emp_rec IN c1 LOOP

...

salary_total := salary_total + emp_rec.sal; END LOOP;

To reference the individual fields in the record, you use dot notation, in which a dot (.) serves as the component selector.


Related Discussions:- Cursor for loops

Table literals - sql, Table Literals - SQL One might expect SQL to sup...

Table Literals - SQL One might expect SQL to support table literals in the manner illustrated in Example 2.2, but in fact that is not a legal SQL expression. Example: Not a

Explicit cursors, Explicit Cursors The set of rows returned by the que...

Explicit Cursors The set of rows returned by the query can include zero, one, or multiple rows, depending on how many rows meet your search criteria. Whenever a query returns

Transaction control, Transaction Control The Oracle is transaction orie...

Transaction Control The Oracle is transaction oriented; that is, Oracle uses the transactions to make sure the data integrity. The transaction is a sequence of SQL data manip

Exception handling, set serveroutput on declare a number(5); b n...

set serveroutput on declare a number(5); b number(5); c number(5); begin a:=&a; b:=&b; c:=a/b; dbms_output.put_line(c); exception when zero_d

Projection in sql - correct version, Projection in SQL - correct version ...

Projection in SQL - correct version Student StudentId is enrolled on some course. SELECT DISTINCT StudentId FROM IS_ENROLLED_ON In more complicated examples it is someti

Calling constructors in pl sql, Calling Constructors: The Calls to a c...

Calling Constructors: The Calls to a constructor are allowed wherever the function calls are allowed. Similarly to the functions, a constructor is called as a section of an ex

Features of pl/sql, Main features of PL/SQL A good way to get familiar ...

Main features of PL/SQL A good way to get familiar with PL/SQL is to look at a sample program. The below program processes an order for tennis rackets. At first, it declares a

Existential quantification - sql, Existential Quantification - SQL Ex...

Existential Quantification - SQL Existential quantification-stating that something is true of at least one object under consideration-can be expressed by OR(r,c), meaning tha

Dbms, DBMS: The answer to this question is of course given in of the t...

DBMS: The answer to this question is of course given in of the theory book. This book is concerned with SQL DBMSs and SQL databases in particular. Soon we will be looking a

Aggregate operators sql, Aggregate Operators SQL Supports all of the a...

Aggregate Operators SQL Supports all of the aggregate operators mentioned in the theory book and many more besides. The syntax, however, involves an unusual trick that SQL cal

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