Example of except operator - sql, PL-SQL Programming

Assignment Help:

Example of EXCEPT Operator - SQL

Example, like its counterpart in the theory book, illustrates the convenience of allowing any table expression to be the source for an INSERT. It assumes that all the exam scripts submitted by students have been marked and it has been decided to record marks of zero for students who failed to turn up for an exam they should have sat. (Remember that SQL's EXCEPT requires its operands to be of the same degree, unlike NOT MATCHING-hence the third element, 0, of the second operand in the example.)

Example: Awarding zero marks to students who failed to take the exam

INSERT INTO EXAM_MARK

SELECT StudentId, CourseId, 0

FROM IS_ENROLLED_ON

EXCEPT

SELECT StudentId, CourseId, 0

FROM EXAM_MARK;


Related Discussions:- Example of except operator - sql

Avoid the not null constraint - performance of application, Avoid the NOT N...

Avoid the NOT NULL Constraint In the PL/SQL, using the NOT NULL constraint incur a performance cost. Consider the illustration as shown below: PROCEDURE calc_m IS m NUMB

Unnest operator in sql, UNNEST operator in SQL The inverse operator of...

UNNEST operator in SQL The inverse operator of GROUP is UNGROUP. SQL has an operator, UNNEST, that can be used for similar purposes, but its method of invocation is somewhat p

Primary key, PRIMARY KEY: PRIMARY KEY  indicates that the table is sub...

PRIMARY KEY: PRIMARY KEY  indicates that the table is subject to a key constraint, in this case declaring that no two rows in the table assigned to ENROLMENT can ever have the

Error handling in pl/sql, Error Handling The PL/SQL makes it easy to de...

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

Keyword & parameter description - expressions, Keyword & Parameter Descript...

Keyword & Parameter Description: boolean_expression: This is an expression which yields the Boolean value that is TRUE, FALSE, & NULL. character_expression: This

Creating Views, Create a view named CustomerAddresses that shows the shippi...

Create a view named CustomerAddresses that shows the shipping and billing addresses for each customer in the MyGuitarShop database. This view should return these columns from the

Use of table expressions - expressing constraint conditions, Use of Table E...

Use of Table Expressions - Expressing Constraint Conditions With the exception of key constraints, the examples in the theory book all explicitly reference at least one relvar

Advantages of packages, Advantages of Packages The benefits of the Pack...

Advantages of Packages The benefits of the Packages are as shown below: Modularity The Packages encapsulate logically associated items, types, and subprograms in the

Bulk fetching - bulk bind performance improvement, Bulk Fetching The i...

Bulk Fetching The illustration below shows that you can bulk-fetch from a cursor into one or more collections: DECLARE TYPE NameTab IS TABLE OF emp.ename%TYPE; TYPE S

Cause of indeterminacy in sql, Cause of Indeterminacy in SQL One root ...

Cause of Indeterminacy in SQL One root cause of indeterminacy in SQL lies in its implementation of comparison for equality. For certain system-defined types it is possible for

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