ODBC, OLE DB, ADO, and ASP Questions and Answers

Answer: B

Correct answer: True

The Recordset represents the rows retrieved from a data source and provides the cursor for moving through them. The Connection object establishes the link to the source and the Command object carries the instruction to be executed.

Answer: A

Correct answer: ODBC

ODBC, Open Database Connectivity, is the standard interface by which a program issues SQL to any compliant DBMS without knowing which one it is talking to. The independence is achieved by the driver, which translates the standard calls into whatever the particular DBMS requires, so the application itself needs no change to move between products.

Answer: A

Correct answer: Properties

Properties are the characteristics an object exposes - for a recordset, things such as its current position, whether it can be updated, and how many rows it holds. Methods are the actions it can perform, such as moving or updating, and collections group objects together. The distinction is between what an object is and what it does.

Answer: B

Correct answer: OLE DB

OLE DB is object-oriented and COM-based: it wraps data-server functionality in objects with defined interfaces, so that a provider can implement the pieces it supports and consumers can use whatever is offered. ODBC is a procedural, SQL-oriented interface by contrast, and ADO is a simplified object cover over OLE DB.

Answer: B

Correct answer: False

A user data source is the most restricted of the three: available only to the user who created it, on the computer where it was created. The shareable one is the file data source, whose details live in a file that can be placed on a shared drive. A system data source falls between the two.

Answer: B

Correct answer: False

The first half is right and the second is wrong. ADO does overlie the more complex OLE DB model, and that is its purpose - but it is callable from programming languages as well as scripting ones, from Visual Basic and C++ as readily as from VBScript. Being usable from almost any language able to work with COM is exactly what ADO was created for.

Answer: A

Correct answer: True

ODBC is DBMS-independent by design and is used by web server programs as readily as by any other application: the program issues standard calls, names a data source, and the driver translates for whatever database lies behind it. This is exactly what allows a web application to be moved from one DBMS to another without rewriting its data access code.

Answer: D

Correct answer: exposes data via rowsets.

A tabular data provider owns data and presents it as rowsets, the OLE DB abstraction of a set of rows. The other three descriptions belong to a service provider, which owns nothing, transforms what it is given, and acts as both consumer and provider - the distinction between the two kinds of provider is precisely whether they own data.

Answer: A

Correct answer: data source.

A data source is the ODBC data structure that names both the database and the DBMS that processes it, together with whatever else is needed to reach it. It is what an application connects to by name, and the indirection is the point: change which database the name refers to and the application follows without being recompiled.

Answer: A

Correct answer: True

This is the definition. The data source names both the database and the DBMS that processes it, along with the other details needed to reach it, and the application connects to it by name. The indirection is deliberate: what the name refers to can be changed without touching the application.