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!
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 been the case. A salary history table for employees, with columns From and To for dates defining the applicable time periods, would be a good example.
A constraint is needed to avoid the possibility of an employee being shown as having two different salaries on the same day, which could happen if two rows for the same employee have overlapping periods indicated by their From and To dates. The term "WHEN/THEN constraint" appeals to the notion of "unpacking" the table so that each row is replaced by one or more rows, one for each date contained in its from-to period: when the relation is unpacked, then the given key constraint (e.g., on employee number and date) is to hold.
Use the MASCOT tables CREDITRS, PORDS and PAYMENTS to write SQL queries to solve the following business problems. These tables / data are available to you via the USQ Oracle server
WHILE-LOOP The WHILE-LOOP statement relates a condition with the series of statements enclosed by the keywords LOOP and END LOOP, as shown: WHILE condition LOOP sequence_of_sta
Using EXCEPTION_INIT To handle unnamed internal exceptions, you should use the OTHERS handler or the pragma EXCEPTION_INIT. The pragma is a compiler directive that can be th
Create a procedure named STATUS_SHIP_SP that allows a company to employee in the Shipping Department to update the status of an order to add shipping information. The BB_BASKETSTAT
Naming Conventions The similar naming conventions apply to all PL/SQL program items and units including the variables, cursors, constants, cursor variables, procedures, exception
Loop Labels Like the PL/SQL blocks, loops can also be labeled. The label, an undeclared identifier enclosed by double angle brackets, should appear at the beginning of the LOOP
Processing Transactions This part describes how to do the transaction processing. You learn the fundamental techniques that safeguard the consistency of your database, involvin
What Are Cursor Variables ? The Cursor variables are like C or Pascal pointers that hold the memory location (address) of some item rather of the item itself. Therefore, decl
Semidifference and NOT - SQL In this section first describe the relational difference operator, named MINUS. Example here shows SQL's closest counterpart of that operator.
What is Cursors how to use it in Real time application ?
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