Effects of null for table expression, PL-SQL Programming

Effects of NULL for Table Expression

Here's an important distinction between expressions denoting tables and expressions denoting multisets of rows: a table expression cannot evaluate to NULL, whereas a multiset expression can. Moreover, although a row expression can evaluate to NULL-for instance, CAST ( NULL AS ROW ( X INTEGER, Y INTEGER ) ) is a legal expression-NULL cannot appear as an element of the body of a table. Every element of the body of a table is indeed a row. However, if a table has a column whose declared type is a row type, then NULL might appear in place of a value for that column in some row of that table.

Posted Date: 1/18/2013 7:46:56 AM | Location : United States







Related Discussions:- Effects of null for table expression, Assignment Help, Ask Question on Effects of null for table expression, Get Answer, Expert's Help, Effects of null for table expression Discussions

Write discussion on Effects of null for table expression
Your posts are moderated
Related Questions
Keyword &Parameter Description: index_name: This is an undeclared identifier which can be referenced only within the FORALL statement and only as the collection subscript

%FOUND Subsequent to a cursor or cursor variable is opened but before the first fetch, the %FOUND yields NULL. Afterward, it yields TRUE when the last fetch returned a row, or

We are seeking a freelance consultant that is familiar with Appgen applications. We require exporting all our data into a format appropriate for importing into SAP Business One. Pl

Create a view named CustomerAddresses that shows the shipping and billing addresses for each customer in the MyGuitarShop database. This view should return these columns from the

TYPES OF EVOLUTION - Sequential evolution                  :                    Minor changes in the gene pool of a population from one generation to the next, with the resul

Positional Notation The first procedure call uses the positional notation. The PL/SQL compiler relates the first actual parameter, account, with the first proper parameter, ac

Logical Connectives - SQL SQL's extended truth tables in which the symbol, for unknown, appears along with the usual T and F. Negation (NOT, ¬) Conjunction (

ROWNUM The ROWNUM returns a number representing the order in which a row was selected from the table. The first row selected has a ROWNUM of 1; the second row has a ROWNUM of

I need SQL Data Base Project Description: Network SQL database and SQL Setup two 4 workstation Skills required are Data Entry, MySQL, SQL

Parameter and Keyword Description: select_item: This select_item is a value returned by the SELECT statement, and then assigned to the equivalent variable or field in the