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!
CHECK Constraints in SQL
A CHECK constraint is a table constraint defined using the key word CHECK, as already illustrated in several examples in this chapter. In particular, a CHECK constraint can be used to express a constraint such as the one shown in Example, referred to in the theory book as a tuple constraint (so one might call it a row constraint in SQL). This is clearly the way most SQL users would prefer to express such a constraint.
Closest Approximation to Relational Union - SQL Actually, just as SQL has several varieties of JOIN, it also has several varieties of UNION, none of which is equivalent to th
Example of NOT EXISTS Operator - SQL Example is a translation into SQL of the corresponding example, which is included there merely to show that for any scalar comparison the
THEO R Y OF ETERNITY OF LIFE (PRAYER - 1880) - The theory of eternity of life, also called the steady-state theory , states that life has ever been in existence as at presen
BIOCHE M ICA L ORIGIN OF LIFE - It is generally agreed by astronomers, geologists and biologists that the earth is approximately 4500-5000 million years old. It is an
Query: SELECT * FROM EMPLOYEE1; Select 5 columns and all rows from one table Query: SELECT C_ID, COMPANY, BUILDING, DEPARTMENT, BRANCH FROM CONTRACT;
Advantages of Exceptions Using the exceptions for the error handling has many benefits. Without an exception handling, every time you issue a command, you should ensure for th
Managing Cursors The PL/SQL uses 2 types of cursors: implicit and explicit. The PL/SQL declares a cursor implicitly for all the SQL data manipulation statements, including th
Row Counterparts of Table Operators SQL does not have counterparts tuple rename, tuple projection, tuple extension, tuple join and tuple compose. To obtain the same effects as
Using NOT NULL Besides assigning an initial value, the declarations can impose the NOT NULL constraint, as the example below shows: acct_id INTEGER(4) NOT NULL := 9999; You ca
Subprograms The PL/SQL has two types of subprograms known as the procedures and functions that can take parameters and be invoked. As the following example represents, a subp
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