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

Data types in sql - xml, Data Types in SQL - XML, Array, Row ...

Data Types in SQL - XML, Array, Row BINARY LARGE OBJECT for arbitrarily large bit strings. XML for XML documents and fragments. ARRAY types for arrays.

Tautology - equivalences rules, Tautology - Equivalences Rules: If the...

Tautology - Equivalences Rules: If there Tautologies are not all the time as much easy to note as the one above so than we can use these truth tables to be definite that a sta

Use bulk binds - improve performance of application, Use Bulk Binds If...

Use Bulk Binds If SQL statements execute inside a loop using the collection elements as bind variables, context switching between the PL/SQL & SQL engines can slow down the ex

Information hiding in pl/sql, Information Hiding   With the informatio...

Information Hiding   With the information hiding, you see only the details that are significant at a given level of algorithm and data structure design. The Information hiding

Write an anonymous block that contains a pl/sql function, a. Write an anon...

a. Write an anonymous block that contains a PL/SQL function. Given an order number orderNo, the function will calculate the total number of the parts in the order. Then the anonym

Organic evolution, Organi c Evolution Evolution is a slow continuou...

Organi c Evolution Evolution is a slow continuous, irreversible and natural process of change to give rise to advance and diverse forms of life i.e. formation of new specie

Dynamic ranges- iterative control, Dynamic Ranges The PL/SQL lets you det...

Dynamic Ranges The PL/SQL lets you determine the loop range dynamically at run time, as the example below shows: SELECT COUNT(empno) INTO emp_count FROM emp; FOR i IN 1..emp_cou

Example of groupby operator - sql, Example of GROUPBY Operator Example...

Example of GROUPBY Operator Example: How many students sat each exam, using GROUP BY, NATURAL LEFT JOIN, and COALESCE SELECT CourseId, COALESCE (n, 0) AS n FROM COURS

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

Explicit cursors, Explicit Cursors The set of rows returned by the que...

Explicit Cursors The set of rows returned by the query can include zero, one, or multiple rows, depending on how many rows meet your search criteria. Whenever a query returns

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