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

Truth tables , Truth Tables: However in propositional logic - here we ...

Truth Tables: However in propositional logic - here we are restricted to expressing sentences and where the propositions are true or false - so we can check where a particular

When or then key constraints, WHEN or THEN Key Constraints Suppose a t...

WHEN or THEN Key Constraints Suppose a table has two columns representing a period of time throughout which the information conveyed by the other columns is recorded as having

Varrays versus nested tables, Varrays versus Nested Tables The Nested ta...

Varrays versus Nested Tables The Nested tables are differing from varrays in the following ways: 1)  Varrays have a maximum size, while nested tables do not. 2)  Varrays are

Passing cursor parameters, Passing Cursor Parameters You use the OPEN ...

Passing Cursor Parameters You use the OPEN statement to pass the parameters to a cursor. Unless you want to accept the default values, each proper parameter in the cursor decl

Package body in pl/sql, Package Body: The package specification is imp...

Package Body: The package specification is implemented by the package body. That is, the package body has the definition of every cursor and the subprogram declared in the pac

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

Boolean values-assignments in pl/sql, Boolean Values Only the values TRU...

Boolean Values Only the values TRUE, FALSE, & NULL can be assigned to a Boolean variable. For illustration, given the declaration DECLARE done BOOLEAN; the following statements

Lob types in pl/sql, LOB Types The large object (LOB) datatypes like BF...

LOB Types The large object (LOB) datatypes like BFILE, BLOB, CLOB, and NCLOB store the blocks of unstructured data (like graphic images, text, video clips, and sound waveforms)

Update statement - syntax, UPDATE Statement   The UPDATE statement tra...

UPDATE Statement   The UPDATE statement transforms the values of the specified columns in one or more rows in the table or view. Syntax:

Parameter & keyword description - functions, Parameter & Keyword Descriptio...

Parameter & Keyword Description: function_name: The user-defined function is identifying by that keyword. parameter_name: This identifies the formal parameter that

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