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!
Example of Table Literal - SQL
Example: A Table Literal (correct version)
VALUES
('S1', 'C1', 'Anne'),
('S1', 'C2', 'Anne'),
('S2', 'C1', 'Boris'),
('S3', 'C3', 'Cindy'),
('S4', 'C1', 'Devinder')
Now, the question arises, what is the (table) type of the table shown in Example? For that matter, what is the (row) type of ('S1', 'C1', and 'Anne')? In particular, what are the field names of those three fields, which would become column names for the containing table? The short answer is that they are determined by the context in which the expression appears. Because the components are distinguished anyway by ordinal position, the field names sometimes serve little or no purpose. In fact several fields are permitted to acquire the same name. Also, sometimes the context does not provide any names at all, in which case, according to the standard, each field is assigned a unique but unpredictable name.
Examples arising as we go along will make this issue a little clearer. I shall use the term anonymous column to refer to a column whose name is unpredictable and therefore effectively undefined. Note carefully that if the word ROW is omitted and the row consists of a single field, then the parentheses can also be omitted. Thus, VALUES 'S1' denotes a table consisting of a single column and a single row, the SQL counterpart of RELATION { TUPLE { StudentId 'S1' } } (though the SQL counterpart has nothing corresponding to the attribute name).
DBMS: The answer to this question is of course given in of the theory book. This book is concerned with SQL DBMSs and SQL databases in particular. Soon we will be looking a
UPDATE Command- SQL Loosely speaking, UPDATE changes some of the column values of some existing rows of its target table. Thus, although some rows disappear from the target an
Using ROLLBACK The ROLLBACK statements end the present transaction and undo any change made during the transaction. The Rolling back is helpful for two reasons. Firstly, if yo
Table Literals - SQL One might expect SQL to support table literals in the manner illustrated in Example 2.2, but in fact that is not a legal SQL expression. Example: Not a
Scope Rules You cannot declare an exception twice in the similar block. Though, you can, declare the similar exception in 2 different blocks. The Exceptions declared in a bloc
Keyword and Parameter Description: label_name: This is an undeclared identifier which optionally labels the PL/SQL block. When used, label_name should be enclosed by the do
Declaring Subprograms You can declare subprograms in any PL/SQL subprogram, block, or package. But, you should declare subprograms at the end of the declarative part after a
Pl/sql Conditional Control: IF statements Frequently, it is necessary to take the alternative actions depending on the circumstances. The IF statement execute a series of statem
SQL Operators The PL/SQL uses all the SQL set, comparison, and row operators in the SQL statements. This part briefly describes some of these operators. 1. Comparison Opera
Comparison Operators Usually, you use the comparison operators in the WHERE clause of a data manipulation statement to form the predicates, that compare one expression to anot
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