S, PL-SQL Programming

Assignment Help:
Question 1. Update stock levels when the order is cancelled

At times, customers make mistakes in submitting their orders and call to cancel the order. Brewbean’s wants to create a trigger that automatically updates the stock level of all products associated with a cancelled order and that updates the ORDERPLACED column of the BB_BASKET table to zero, reflecting that the order was not completed. Create a trigger named BB_ORDERCANCEL_TRG to accomplish this task by considering the following items:

1. The trigger needs to fire when a new status record is added to the BB_BASKETSTATUS table and when the IDSTAGE column is set to 4, which indicates order cancellation.
2. Each basket can contain multiple items in the BB_BASKETITEM table, so a CURSOR FOR loop may be an appropriate mechanism to update the stock level of each item.
3. Keep in mind that coffee can be ordered in half o whole pounds.
4. Use basket 6 for testing. Note that this basket contains two items.
a. Open or return to SQL Plus. Execute the following statement to test the trigger:

Insert into bb_basketstatus (idstatus, idbasket, idstage, tdstage) values (bb_status_seq.nextval, 6, 4, sysdate);

b. Execute queries to confirm that the basket order status and product stock levels have been appropriately modified by the trigger.
c. Be sure to run the following statement to disable this trigger so that it does not affect other products:

Alter trigger bb_ordcancel_trg disable;

Related Discussions:- S

Fetch statement - syntax, FETCH Statement The FETCH statement retrieve ...

FETCH Statement The FETCH statement retrieve rows of data one at a time from the result set of the multi-row query. The data is stored in fields or variables which correspond t

Union all - sql, UNION ALL - SQL Further varieties of UNION arise when...

UNION ALL - SQL Further varieties of UNION arise when we replace the key word DISTINCT by ALL in any of the foregoing examples, as in Example. ALL specifies that if row r appe

Assignment statement in pl sql, Assignment Statement: The assignment s...

Assignment Statement: The assignment statement sets the present value of the variable, parameter, field, or element. The statement consists of an assignment target followed by

Restriction and and - sql, Restriction and AND - SQL Restriction is av...

Restriction and AND - SQL Restriction is available via the WHERE operator, and so it is in SQL. However, by Example showing how a certain simple restriction can be expressed u

Parameter and keyword description - packages, Parameter and Keyword Descrip...

Parameter and Keyword Description: package_name: This construct identifies the package. AUTHID Clause: This determine whether all the packaged subprograms impleme

Functions in pl/sql, Functions   The function is a subprogram that cal...

Functions   The function is a subprogram that calculates a value. The Functions and procedures are structured similar, except that the functions have a RETURN clause. You can

Selecting objects in pl sql, Selecting Objects: Suppose that you have ...

Selecting Objects: Suppose that you have run the SQL*Plus script below that creates object type Person and object table persons, and that you have settled the table: CREATE

Redeclaring predefined exceptions - user-defined exceptions, Redeclaring Pr...

Redeclaring Predefined Exceptions Keep in mind that, the PL/SQL declares predefined exceptions globally in the package STANDARD; Therefore you need not declare them yourself.

Transaction visibility, Transaction Visibility As the figure shows, th...

Transaction Visibility As the figure shows, the changes made by an autonomous transaction become visible to another transaction whenever the autonomous transaction commits. Th

Closing a cursor variable, Closing a Cursor Variable The CLOSE stateme...

Closing a Cursor Variable The CLOSE statement disables the cursor variable. After that, the related result set is undefined. The syntax for the same is as shown below: CLOS

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