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.
Exceptions An exception is the runtime error or warning condition that can be predefined or user-defined. The Predefined exceptions are raised implicitly through runtime system
(a) What are decision support systems, and what role do they play in the business environment? (b) Data warehousing is defined as "a subject-oriented, integrated, non-volatile c
Literals A literal is an explicit numeric, string, character, or Boolean value not represented by an identifier. Numeric literal 147 and the Boolean literal FALSE are some of
Committing and Rolling Back The COMMIT and ROLLBACK end the active autonomous transaction but do not exit the autonomous routine. As the figure shows, if one transaction ends,
Constants and Variables: You can declare the constants and variables in the declarative section of any PL/SQL subprogram, block, or package. The Declarations allot the stor
Effects of NULL for union - SQL The treatment of NULL in invocations of EXCEPT is as for UNION. This is different from its treatment in those of NOT IN and quantified compari
Question 1 . Compare SQL and PL/SQL Question 2 . Write a database trigger to implement the following check condition Given the following table
Using Savepoints The scope of the savepoint is a transaction in which it is defined. The Savepoints defined in the major transaction are not related to the savepoints defined
GOTO Statement The GOTO statement branches categorically to a block label or statement label. The label should be exclusive within its scope and should precede a PL/SQL bloc
Project Description: This is stage 1 of a larger conversion project. We are converting a traditional Server/Client application written in Access 2007 into a web interface with S
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