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!
Initializing Records
The illustration below shows that you can initialize a record in its type definition. Whenever you declare a record of the type TimeRec, its 3 fields suppose an initial value of zero.
DECLARE
TYPE TimeRec IS RECORD (
secs SMALLINT := 0,
mins SMALLINT := 0,
hrs SMALLINT := 0);
The illustration later shows that you can impose the NOT NULL constraint on any field, and so avoid the assigning of nulls to that field. The Fields declared as NOT NULL should be initialized.
TYPE StockItem IS RECORD (
item_no INTEGER(3) NOT NULL := 999,
description VARCHAR2(50),
quantity INTEGER,
price REAL(7,2));
Effects of NULL in Aggregate Operator - SQL Let aggop(x) be an invocation of some aggregate operator aggop in SQL, where x is an expression (usually an open expression) to be
Avoiding Collection Exceptions In many cases, if you reference a nonexistent collection element, then PL/SQL raises a predefined exception. Consider the illustration shown b
Existential Quantification - SQL Existential quantification-stating that something is true of at least one object under consideration-can be expressed by OR(r,c), meaning tha
Example of Cast Operator So long as CAST is used as shown, we could obtain the total marks for each exam in similar fashion, using SUM (Mark) AS TotalMarks. However, this giv
V ariables and Constants in PL/SQL The PL/SQL permits you to declare constants and variables, and then use them in SQL and procedural statements anywhere in the expression. Th
Raise_application_error - procedure of package DBMS_STANDARD , allows to issue an user_defined error messages by stored sub-program or database trigger.
Biconditional - SQL The biconditional p ↔ q can be expressed in Tutorial D by p = q and the same is true of SQL. The question then arises as to whether, in SQL, p = q is equiv
UNION without CORRESPONDING - SQL The use of UNION without CORRESPONDING. Example is merely by omitting CORRESPONDING, but only because the operands have identical SELECT clau
OUT Mode An OUT parameter returns values to the caller of a subprogram. Within the subprogram, an OUT parameter act like a variable. That means that you can use an OUT formal
Question: (a) The objective of query optimization is to choose the most efficient strategy for implementing a given relational query, thereby improving the system performance. On
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