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!
"Not Enforced" Table Constraints
A constraint that is not enforced is not really a constraint within the meaning of the act, but SQL does have such a concept and it needs to be mentioned here. With the exception of UNIQUE and PRIMARY KEY specifications, a table constraint can be declared as either ENFORCED (the default option) or NOT ENFORCED. The "enforcement characteristic" of such a constraint can be changed by means of an ALTER TABLE statement. For example, the table constraint MAX_ENROLMENTS becomes not enforced by execution of the statement ALTER TABLE ALTER CONSTRAINT MAX_ENROLMENTS NOT ENFORCED. The immediate effect is the same (ignoring effects on the catalog) as if ALTER TABLE DROP CONSTRAINT MAX_ENROLMENTS had been given. However, it's easier to reinstate the constraint using ALTER TABLE ALTER CONSTRAINT MAX_ENROLMENTS ENFORCED. NOT ENFORCED cannot be specified for domain constraints or assertions, so use of CREATE ASSERTION should really be the preferred method of declaring a constraint, but unfortunately that option is not widely available.
Need Windows and Linux system Administrator We are seeking a part time system administrator to take care of our servers. Your things to do would add, but not limited to: -
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
Using Operator DEREF: You cannot navigate through refs within the PL/SQL procedural statements. Rather than, you should use the operator DEREF in the SQL statement. The DEREF
Using the BULK COLLECT Clause The keywords BULK COLLECT specify the SQL engine to bulk-bind output collections before returning them to the PL/SQL engine. You can use these ke
Example of Shorthand for a row constraint Example: Shorthand for a row constraint ALTER TABLE EXAM_MARK ADD CONSTRAINT Mark_in_range CHECK (Mark BETWEEN 0 AND 100);
Defining and Declaring Collections To create the collections, you must define a collection type, and then declare the collections of that type. You can define the VARRAY types a
Pl/sql Conditional Control: IF statements Frequently, it is necessary to take the alternative actions depending on the circumstances. The IF statement execute a series of statem
THEO R Y OF PANSPERMIA - Arrhenius (1908) postulated the cosmic panspermia theory that claims that organisms existed throughout the universe, and their spores, etc., could
Parameter Aliasing To optimize the subprogram call, the PL/SQL compiler can decide between the two techniques of the parameter passing. With the by-value techniques, the v
Using RENAME in combination with JOIN - SQL Example gives pairs of ids of students having the same name, by joining two renamings of IS_CALLED. Example gives an equivalent ex
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