Oracle PL/SQL Programming: A Developer's Workbook

Intermediate

Q:
9-16.	The statements are: False. This view lists “database objects” (as opposed to “object objects”) owned by the user, such as tables, procedures, and packages. USER_OBJECTS has been around for quite some time. Now with the Objects option, its name will be confusing. True. An object type is a database construct, created with a CREATE TYPE statement, and therefore appears in the USER_OBJECTS view. False. An object instance, which can be a persistent row in an object table or held temporarily in a PL/SQL variable, does not have an entry in USER_OBJECTS. This is consistent with Oracle’s treatment of other rows in (nonobject) tables and values held in (nonobject) PL/SQL variables.
Q:
9-17.	The statements are: False. The constructor function cannot be modified. True. The constructor can be called in SQL or PL/SQL. True. Like other Oracle functions, the constructor can use named notation or positional notation: DECLARE cd_to_avoid CD_t; BEGIN cd_to_avoid := CD_t ( id => -1000000, artist => 'Garth Brooks', title => 'Salutes The Chipmunks', label => 'Nonesuch' ); Constructor CD_t is invoked using this named notation.
Q:
9-18.	An object type attribute cannot have a DEFAULT value (e.g., ‘Greatest Hits’). This means that a call to a constructor must supply a value—or the nonvalue NULL—for every attribute of the object type.
Q:
9-19.	The syntax for creating an object type specification is a comma-separated list of attributes and methods; you do not use semicolons in the list, as you’d find in ...