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

Forall statement - syntax, FORALL Statement The FORALL statements instr...

FORALL Statement The FORALL statements instruct the PL/SQL engine to bulk-bind the input collections before sending them to the SQL engine. Though the FORALL statement consists

Triggers, At times, customers make mistakes in submitting their orders and ...

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 pr

Existential quantification - sql, Existential Quantification - SQL Ex...

Existential Quantification - SQL Existential quantification-stating that something is true of at least one object under consideration-can be expressed by OR(r,c), meaning tha

Example of foreign key constraint - sql, Example of Foreign Key Constraint ...

Example of Foreign Key Constraint Example: Alternative formulation for 6.3 as a foreign key constraint ALTER TABLE EXAM_MARK ADD CONSTRAINT Must_be_enrolled_to_take_exam

Cursor variables as parameters, Cursor Variables As Parameters You can...

Cursor Variables As Parameters You can declare the cursor variables as the formal parameters of the functions and procedures. In the illustration below, you define the REF CUR

Pl/sql expressions , Pl/SQL Expressions The Expressions are constructed...

Pl/SQL Expressions The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value

Iteration schemes- iterative control, Iteration Schemes The bounds of a ...

Iteration Schemes The bounds of a loop range can be variables, literals, variables, or expressions but must compute to integers. Below are some of the examples. As you can see t

Group and having query, Using a join on 2 tables, select all columns and 10...

Using a join on 2 tables, select all columns and 10 rows from the 2 tables without the use of a Cartesian product. Query: SELECT * FROM EMPLOYEE1 E JOIN STAFF S ON E.EMP_

Substitution and instantiation - sql, Substitution and Instantiation - SQL ...

Substitution and Instantiation - SQL It shows how NULL might appear in substitution for a parameter of a predicate and how it might thus participate in instantiation of that p

Cartesian product, Using a Join on 2 tables, select all columns and all row...

Using a Join on 2 tables, select all columns and all rows from the tables without the use of a Cartesian product. Query: SELECT * FROM EMPLOYEE1 JOIN CONTRACT ON EMPLOYEE

Write Your Message!

Name

Email id

Message

Verfication Code

User Account

All Pages