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!
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 expression in SQL.
Example: Renaming and joining
Student Sid1 is called Name and so is student Sid2
SELECT *
FROM (SELECT StudentId AS Sid1, Name FROM IS_CALLED)
NATURAL JOIN
(SELECT StudentId AS Sid2, Name FROM IS_CALLED)
As before, the result sagely tells us that student S1 (Anne) has the same name as herself and also shows two pairings of S1 with S5 (both named Boris). The pairing of a student id with itself can be avoided by adding WHERE Sid1 < > Sid2 to the WHERE clause. The duplicate pairings can further be avoided by using < instead of < > in this addition, but that trick assumes that an ordering is defined for type SID, which is not necessarily the case.
Declaring Records Whenever you define a RECORD type, you may declare records of that type, as the illustration shows: DECLARE TYPE StockItem IS RECORD ( item_no INTEG
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
Project Description: I want a small relational database to be built. I want the database to have the subsequent information tables: Employee Information Document storage
EXIT The EXIT statement forces a loop to done unconditionally. Whenever an EXIT statement is encountered, the loop is done immediately and controls the passes to the next statem
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);
Closing a Cursor The CLOSE statements disable the cursor, and the result set becomes undefined. An illustration of the CLOSE statement as shown: CLOSE c1;
Parameter and Keyword Description: package_name: This construct identifies the package. AUTHID Clause: This determine whether all the packaged subprograms impleme
1- You can check attribute names from each table in DBF11 by running for example: desc dbf11.Member; desc dbf11.Agent; desc dbf11.Producer; Because some attribute names in
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
Extension and AND in SQL The theory book gives the following simple example of relational extension in Tutorial D: EXTEND IS_CALLED ADD ( FirstLetter ( Name ) AS Initial )
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