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

Answer: A

Correct answer: True

A collection is an object whose purpose is to hold a group of other objects, so that they can be counted, iterated over and reached by index or name. The errors collection on an ADO connection is the familiar example. Collections sit alongside properties and methods as the three things an object exposes.

Answer: B

Correct answer: False

The terms are the wrong way round. A provider supplies data through OLE DB interfaces; a consumer uses it. Users of OLE DB functionality are therefore data consumers. The two roles can be held at once - a service provider consumes from below and provides above - which is what lets providers be chained.

Answer: B

Correct answer: False

This describes the driver, not the driver manager. The driver is the DBMS-specific component that turns ODBC requests into statements the particular data source understands. The driver manager’s job is to decide which driver a named data source requires, load it, and pass the calls through to it.

Answer: C

Correct answer: methods.

In the object model an object has properties, which are the characteristics it exposes, and methods, which are the actions it can perform. A collection is an object that contains a group of other objects. The vocabulary matters because an OLE DB interface is defined precisely as the set of objects it exposes together with their properties and methods.

Answer: A

Correct answer: True

This is the whole purpose of the interface. The application issues standard ODBC calls and names a data source; the driver manager loads the appropriate driver, and the driver translates those calls for the particular DBMS. Point the data source at a different compliant database and the application works against it unchanged.

Answer: D

Correct answer: All of the above as goals of OLE DB.

All three were stated aims. Breaking DBMS functionality into object interfaces means a provider need implement only the pieces it can support; that flexibility lets a simple source expose a little and a full DBMS expose a great deal; and putting an object interface over any type of data extends the model beyond relational databases to spreadsheets, mail stores and files.

Answer: A

Correct answer: True

Defining a system data source name means telling ODBC two things: which driver to load, and which database that driver is to work with, together with whatever connection details it needs. Once both are recorded, an application need only name the data source, and the driver manager does the rest.

Answer: D

Correct answer: ADO

ADO, ActiveX Data Objects, is a thin object model over OLE DB with only a handful of objects - connection, command, recordset, errors - which makes it far easier to learn than OLE DB itself. Its purpose is to make OLE DB reachable from scripting languages and from ordinary application code without the complexity of the underlying COM interfaces.

Answer: A

Correct answer: True

ODBC does identify exactly these two kinds. A single-tier driver processes both the ODBC calls and the file access itself, which is how a driver for a simple file format such as a spreadsheet works. A multiple-tier driver passes SQL to a separate DBMS, which does the processing, and is the arrangement used for a client-server database.

Answer: C

Correct answer: Driver manager

The driver manager is the intermediary: the application calls it, and it determines which driver the requested data source needs, loads it, and passes the calls through. That indirection is what lets one application work with any compliant DBMS - the application never names a driver, only a data source.