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!
Projection in SQL - correct version
Student StudentId is enrolled on some course.
SELECT DISTINCT StudentId FROM IS_ENROLLED_ON
In more complicated examples it is sometimes quite difficult to tell whether omission of DISTINCT would give rise to duplicate rows. It might therefore seem good advice to always write DISTINCT. Indeed, I would certainly advocate such practice to students having to write SQL expressions in solutions to questions in exam papers, for example, but if it were followed blindly in commercial systems, then many queries would run very much slower than need be because typical SQL implementations have little or nothing in the way of built-in intelligence to recognize cases where duplicate rows cannot possibly arise. Although such intelligence is quite feasible within acceptable limits (and was used in Business System 12, for example), the inclusion of DISTINCT allows SQL implementations to place the responsibility for duplicate elimination on the user.
Fetching with a Cursor The FETCH statements retrieve the rows in the result set one at a time. After each and every fetch, the cursor advance to the next row in the result set
Difference between 9i & 10G When Oracle releases any new databases then it are having some discrepancy with them. But 10G is having much difference than oracle 9i has. Oracle
What are the rates for help in writing PL/SQL procedures and functions?
DBMS_PIPE: The Package DBMS_PIPE allows various sessions to communicate over the named pipes. (A pipe is a region of memory used by one of the process to pass information to
Calling Constructors: The Calls to a constructor are allowed wherever the function calls are allowed. Similarly to the functions, a constructor is called as a section of an ex
Data Types in SQL - Interval, Boolean INTERVAL for values denoting, not intervals (!) but durations in time, such as 5 years, 3 days, 2 minutes, and so on. BOOLEAN, con
Explicit Cursor Attributes The cursor variable or each cursor has four attributes: %FOUND, %ISOPEN, %ROWCOUNT, and %NOTFOUND. When appended to the cursor or cursor variable, th
Keyword and Parameter Description: table_reference: This specifies a table or view that should be accessible when you execute the DELETE statement, and for that you must
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
Overloading: Similar to packaged subprograms, methods of the same type can be overloaded. That is, you can use similar name for various methods if their formal parameters diff
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