Example of check constraints - sql, PL-SQL Programming

Assignment Help:

Example of Check Constraints

Example: Workaround for when subqueries not permitted in CHECK constraints

CREATE FUNCTION NO_MORE_THAN_20000_ENROLMENTS ( )

RETURNS BOOLEAN;

RETURN (SELECT COUNT (*) FROM IS_ENROLLED_ON) <= 20000;

ALTER TABLE IS_ENROLLED_ON

ADD CONSTRAINT MAX_ENROLMENTS

CHECK (NO_MORE_THAN_20000_ENROLMENTS ( ));


Related Discussions:- Example of check constraints - sql

Declaring exceptions - user-defined exceptions, Declaring Exceptions T...

Declaring Exceptions The Exceptions can be declared only in the declarative part of the PL/SQL subprogram, block, or package. By introducing its name, you can declare an excep

Processing transactions, Processing Transactions This part describes ho...

Processing Transactions This part describes how to do the transaction processing. You learn the fundamental techniques that safeguard the consistency of your database, involvin

Positional notation, Positional Notation The first procedure call uses...

Positional Notation The first procedure call uses the positional notation. The PL/SQL compiler relates the first actual parameter, account, with the first proper parameter, ac

Example of table literal - sql, Example of Table Literal - SQL Exampl...

Example of Table Literal - SQL Example: A Table Literal (correct version) VALUES ('S1', 'C1', 'Anne'), ('S1', 'C2', 'Anne'), ('S2', 'C1', 'Boris'), ('S3', 'C3'

Sql, If two relations R and S are joined, then the non matching tuples of b...

If two relations R and S are joined, then the non matching tuples of both R and S are ignored in __________________.

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

S, Question 1. Update stock levels when the order is cancelled At times, c...

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

Using prior and next - collection method, Using PRIOR and NEXT The PRI...

Using PRIOR and NEXT The PRIOR(n) returns the index number that precede index n in a collection. The NEXT(n) returns the index number which succeed the index n. If n has no pr

Declaring and initializing objects in pl/sql, Declaring and Initializing Ob...

Declaring and Initializing Objects: An object type is once defined and installed in the schema; you can use it to declare the objects in any PL/SQL, subprogram, block or packa

If statement - syntax, IF Statement The IF statement executes a series ...

IF Statement The IF statement executes a series of statement conditionally. Whether the series is executed or not depends on the value of the Boolean expression. Syntax:

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