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!
Use the RETURNING Clause
Frequently, the application requires information about the row affected by a SQL operation, for illustration, to produce a report or take a subsequent action. The INSERT, UPDATE, & DELETE statements can involve a RETURNING clause that returns column values from the affected row into the PL/SQL variables or host variables. This removes the requirement to SELECT the row after an insert or update, or before a delete. As a result, less network round trips, less server CPU time, smaller number of cursors, and less server memory are needed.
In the illustration below, you update the salary of an employee and at similar time retrieve the employee's name and new salary into the PL/SQL variables.
PROCEDURE update_salary (emp_id NUMBER) IS
name VARCHAR2(15);
new_sal NUMBER;
BEGIN
UPDATE emp SET sal = sal * 1.1
WHERE empno = emp_id
RETURNING ename, sal INTO name, new_sal;
Name Resolution In potentially uncertain SQL statements, the names of the database columns take precedence over the names of the local variables and formal parameters. For e.g.
Error Handling The PL/SQL makes it easy to detect and process the predefined and user-defined error conditions known as exceptions. Whenever an error occurs, an exception is ra
Definition of CROSS JOIN - SQL Let s = t1 CROSS JOIN t2, where t1 and t2 are table expressions optionally accompanied by range variables. Then: Note: Here T denotes Table
Order of Evaluation When you do not use the parentheses to specify the order of evaluation, the operator precedence determine the order. Now compare the expressions below: NOT
Expressions An expression is a randomly complex combination of the constants, variables, literals, operators, & function calls. The simplest expression is the single variabl
Using a Host Variable You can declare the cursor variable in the PL/SQL host environment like an OCI or Pro C program. To use the cursor variable, you should pass it as a host
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
Enrolment was split - SQL Example shows how relvars IS_CALLED and IS_ENROLLED_ON can be derived from the original ENROLMENT relvar, using projection in the initial assignment
Projection and Existential Quantification - SQL Intuitively it might seem that projection in SQL is simply a matter of specifying the required columns in the SELECT clause, a
Example of GROUPBY Operator Example: How many students sat each exam, using GROUP BY, NATURAL LEFT JOIN, and COALESCE SELECT CourseId, COALESCE (n, 0) AS n FROM COURS
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