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!
Type versus Representation Confusion in SQL
This describes how a value might have two or more distinct representations. For example, user-defined type POINT might have a declared possrep based on Cartesian coordinates and another based on polar coordinates. SQL has a system-defined type, TIMESTAMP, for values representing points in time, a timestamp being represented by a date, a time of day, and-optionally-a time zone, expressed as a displacement from UTC. Clearly any timestamp can be expressed in several different ways, using different time zones.
Three o'clock in the afternoon of December 31st, 2011 in UK, for example, is the same time as two o'clock in the morning of January 1st, 2012 in New Zealand. SQL treats those two representations as distinct values that compare equal, in like fashion to its treatment of character strings with trailing blanks, with similar consequences. If instead it had treated them as distinct representations of the same value, then the issue of indeterminacy would not have arisen.
Example of Null operator - NiNo Rule If we wanted to make HIGHER_OF adhere to "NULL in, NULL out"-let's call it the NiNo rule-we would have to write something like what is sho
MERGE and TRUNCATE in SQL SQL has two more table update operators, MERGE and TRUNCATE. MERGE, like INSERT, takes a source table s and uses it to update a target table t. Brief
Semidifference and NOT - SQL In this section first describe the relational difference operator, named MINUS. Example here shows SQL's closest counterpart of that operator.
Advantages of PL/SQL The PL/SQL is a high-performance transaction processing, completely portable language that offers the following advantages as shown: 1) Support for SQL
Example of WHEN or THEN Constraints A concrete example showing how SQL supports WHEN/THEN constraints CREATE TABLE SAL_HISTORY (EmpNo CHAR (6), Salary INTEGER NOT NULL,
Rephrase Conditional Control Statements When computing a logical expression, the PL/SQL uses short-circuit evaluation. That is, the PL/SQL stops evaluating the expression as s
Question 1 . Compare SQL and PL/SQL Question 2 . Write a database trigger to implement the following check condition Given the following table
Scoping Within the similar scope, all the declared identifiers should be unique. So, even if their datatypes differ, the variables and parameters cannot share the similar name.
Parameter and Keyword Description: cursor_name: This identifies an explicit cursor formerly declared within the present scope. cursor_variable_name: These identif
Negation (NOT, ¬) - SQL There are three rows instead of just two. As you can see, ¬ p is defined as in two-valued logic (2VL) when p is either true or false, but ¬ (unknown) i
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