Visual Basic Interview Questions and Answers
How do you register a component?
Compiling the component, running REGSVR32 MyDLL.dll
Name and explain the different compatibility types when
creating a COM component
No Compatibility ? New GUID created, references from
other components will not workProject Compatibility ?
Default for a new component Binary Compatibility ? GUID
does not change, references from other components will
Why is it important to use source control software for
Modification history.Code ownership: Multiple people can
not modify the same code at the same time.
What two methods are called from the ObjectContext
object to inform MTS that the transaction was successful
SetComplete and SetAbort.
What is the tool used to configure the port range and
protocols for DCOM communications?
What does Option Explicit refer to?
All variables must be declared before use. Their type is
What are the different ways to Declare and Instantiate
an object in Visual Basic 6?
Dim obj as OBJ.CLASS with eitherSet obj = New OBJ.CLASS
orSet obj = CreateObject(OBJ.CLASS?) orSet obj =
GetObject( , OBJ.CLASS?)orDim obj as New OBJ.CLASS
Name the four different cursor types in ADO and describe
The cursor types are listed from least to most resource
intensive.Forward Only Fastest, can only move forward in
recordset Static Can move to any record in the recordset.
Data is static and never changes.KeySet Changes are
detectable, records that are deleted by other users are
unavailable, and records created by other users are not
detectedDynamic ? All changes are visible.
Name the four different locking type in ADO and describe
LockPessimistic Locks the row once after any edits
occur.LockOptimistic Locks the row only when Update is
called.LockBatchOptimistic Allows Batch
Updates.LockReadOnly Read only. Can not alter the data.
Describe Database Connection pooling (relative to MTS )?
This allows MTS to reuse database connections. Database
connections are put to sleep as opposed to being created
and destroyed and are activated upon request.
What are the ADO objects?
Provide a scenario using three of them to return data
from a database. Expected answer: Connection Connects to
a data source; contains the Errors collectionCommand
Executes commands to the data source. Is the only object
that can accept parameters for a stored
procedure.Recordset The set of data returned from the
database.Scenario: There are many possibilities. The
most likely is as follows:Dim conn As
ADODB.ConnectionDim rs As ADODB.RecordsetDim Cmd As
ADODB.Commandconn.ConnectionString = ?CONNECTION
STRING?conn.OpenSet Cmd.ActiveConnection =
connCmd.CommandText = ?SQL STATEMENT?Set rs =
Cmd.ExecuteSet rs.ActiveConnection = Nothingconn.Close
Under the ADO Command Object, what collection is
responsible for input to stored procedures?
The Parameters collection.