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 Aggregation on Nested Tables
Example is the most direct translation of its counterpart in the theory book that can be obtained in SQL but it is so over-elaborate that no SQL practitioner would consider using it. It uses the aggregate operator COUNT on the table values for column ExamResult to obtain the number of students who sat each exam. Unfortunately, as already noted, we cannot operate directly on ExamResult as a FROM clause element. Instead, we need to use an artifice that is specially devised for the sake of this example.
Example: How many students sat each exam
WITH C_ER AS (
SELECT CourseId,
CAST (
TABLE (SELECT DISTINCT StudentId, Mark
FROM EXAM_MARK AS EM
WHERE EM.CourseId = C.CourseId)
AS ROW ( StudentId SID, Mark INTEGER ) MULTISET)
AS ExamResult
FROM COURSE AS C)
SELECT CourseId, (SELECT COUNT (*)
FROM TABLE (ER (ExamResult)) AS t) AS n
FROM C_ER
%ROWCOUNT The %ROWCOUNT yields the number of rows affected by the INSERT, UPDATE, or DELETE statement, or returned by a SELECT INTO statement. The %ROWCOUNT yields zero when a
The Package Specification The package specifications contain the public declarations. The scopes of these declarations are local to your database representation and global to t
1.( /5 marks) Suppose that a B+-tree index with the search key (dept_name, building) is available on relation department. What would be the best way to handle the following selecti
Example of Tables within a Table - SQL Example: Obtaining C_ER from COURSE and EXAM_MARK SELECT CourseId, CAST (TABLE (SELECT DISTINCT StudentId, Mark FROM EXAM_MARK AS EM
Attributes: Just similar to variable, an attribute is declared with a name and datatype. The name should be exclusive within the object type. The datatype can be any Oracle ty
Pl/SQL Expressions The Expressions are constructed by using the operands and operators. An operand is a constant, literal, variable, or function call which contributes a value
Deriving Predicates from Predicates in SQL The corresponding section in the theory book describes how predicates can be derived from predicates using (a) the logical connectiv
%ROWCOUNT When its cursor or cursor variable is opened, the %ROWCOUNT is zeroed. Before the first fetch, the %ROWCOUNT yields 0. Afterward, it yields the number of rows fetche
1. Create a procedure called TAX_COST_SP to accomplish the tax calculation task. Keep in mind that the state and subtotal values are inputs into the procedure and the procedure is
Create a procedure named DDPROJ_SP that retrieves project information for a specific project based on a project ID. The procedure should have two parameters: one to accept a projec
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: +1-415-670-9521
Phone: +1-415-670-9521
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd