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!
Use of Table Comparisons - SQL
Table comparisons where it is noted that although table expressions cannot be compared, we have TABLE (t) to convert a table expression t into a value expression of type ROW ( r ) MULTISET, where r is the row type of t. However, the only operator in SQL for comparing two multisets is "=", so SQL has no direct counterparts of examples, which use "⊆", and nor does this chapter.
Those examples are shown merely to demonstrate that every constraint that can be expressed as an invocation of IS_EMPTY can be formulated alternatively as an invocation of "⊆". If SQL were to have a counterpart of that operator, it would presumably have to be an "is submultiset of " operator, where m1 is a submultiset of m2 if and only if each element of m1 appears at least as many times in m2 as it does in m1. But SQL doesn't have such an operator.
Nested Tables versus Index-by Tables The Index-by tables and nested tables are just similar. For e.g. They have similar structure and their individual elements are accessed in
LOOP Statements The LOOP statements execute a series of statements at multiple times. The loops enclose the series of statements that is to be repeated. The PL/SQL provides typ
Example of Using Aggregation on Nested Tables Example: How many students sat each exam WITH C_ER AS (SELECT CourseId, CAST (TABLE (SELECT DISTINCT StudentId, Mark FROM EXAM
Example of COALESCE operator Example: Give the total of marks for each exam (simplified solution) SELECT CourseId, COALESCE ((SELECT SUM (Mark) FROM EXAM_MARK AS EM
Initializing Objects: Till you initialize an object by calling the constructor for its object type, the object is automatically null. That is, the object itself is null, not me
Create a procedure named STATUS_SHIP_SP that allows a company to employee in the Shipping Department to update the status of an order to add shipping information. The BB_BASKETSTAT
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
Referencing Records Unlike the elements in a collection, that are accessed using subscripts, the fields in a record are accessed by name. To reference an individual field, you
Short-Circuit Evaluation When computing a logical expression, the PL/SQL uses short-circuit evaluation. That is, the PL/SQL stops computing the expression as soon as the result
Implicit Rollbacks Before execute the INSERT, UPDATE, or DELETE statement, the Oracle marks an implicit savepoint . When the statement fails, the Oracle rolls back to the save
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