CGI PAPER ON 21st JUNE 2008
1. Why we use Treeview Control?
To list the hierarchial list of the node objects. Such of files and Directories.
2. Why we need OLE-Automation? Advantages?
Enables an application to exposes objects and methods to other Applications. No need to reserve memory. No need to write functions.
Object library that simplify programming tasks. i.e., No need to Object library. (OLB, TLB).
3. What is the diff between the Create Object and Get object?
Create Object – To create an instance of an object.
Get Object ? To get the reference to an existing object.
4. Have you create Properties and Methods for your own Controls?
Properties ? Public variable of a Class
Method ? Public procedure of a classWhat is Collection Objects?
Similarly to arrays but is preferred over an array because of the following reasons.
1. A collection objects uses less Memory than an array.
2. It provides methods to add and delete members.
3. It does not required reason statement when objects are added or deleted.
4. It does not have boundary limitations.
5. What is Static Variable?
Its Scope will be available through out the life time.
Private Dim x as integer. Is it true?
No. Private cannot be used in front of DIM.
6. What is Implicit?
Instance of specific copy of a class with its own settings for the properties defined in that class. Note: The implicity defined variable is never equal to nothing.
7. What are the scope of the class?
Public , private, Friend
Can we able to set Instancing properties like Singleuse, GlobalSingleuse to ActiveXDll?
No.
In project properties if we set Unattended what is it mean?
This cannot have user interface. This can be used for the COM creation.What are the Style Properties of Combo Box?
Simple, Dropdown list ? We can type and select.
Dropdown Combo ? Only Drop Down.
8. What are the Style properties of List Box?
Simple ?Single Select , Extended. ? Multiple Select.
9. What are the different types of Dialog Box?
Predefined, Custom, User Defined.
10. What is Parser Bug?
It is difficult to use database objects declared in a module from within a form.
11. What is the Dll required for running the VB?
Vbrun300.dllCan We create CGI scripts in VB?
Yes.
12. How to change the Mouse Pointer?
Screen. Mouse Pointer = VBHourGlass/VBNormal.
13. How to check the condition in Msgbox?
If (Msgbox(“Do you want to delete this Record”,VbYesNo)=VbYes)Then End if
14. What is difference between datagrid and flexgrid?
Datagrid ? Editable.
Flexigrid ? Non-Editable. (Generally used for Read only purpose.)
15. What is ADO? What are its objects ?
ActiveX Data Object. ADO can access data from both flat files as well as the databases. I.e., It is encapsulation of DAO, RDO, and OLE that is why we call it as OLE-DB Technology. Objects are Connection, Record Set, Command, Parameter, field, Error, Property.
16. What is Dataware Control?
Any control bound to Data Control.
Ex:- Textbox, Check Box, Picture Box, Image Control, Label, List box, Combo Box, DB Combo, What are two validate with Data Control?
Data_Validate, Data_Error.
Record set types and Number available in VB?
3. 1- Dynaset, 0 ? Table, 2 ? Snap Shot.
Referential Integrity (Take care By jet database Engine).
Cascade Delete, Cascade Update ? is done setting property of Attributes.
Db Relation Delete Cascade,
Db Relation Update Cascade.
17. What are the locks available in Visual Basic?
Locking is the process by which a DBMS restricts access to a row in a multi-user environment
4 types of locks. They are
1.Batch Optimistic
2.Optimistic
3.Pessimistic
4.ReadOnly
18. What is the diff between RDO and ADO?
RDO is Hierarchy model where as ADO is Object model. ADO can access data from both flat files as well as the data bases. I.e., It is
encapsulation of DAO, RDO , OLE that is why we call it as OLE-DB Technology.
19. How can we call Stored procedure of Back End in RDO and ADO ?
In RDO ? We can call using RDO Query Objects.
In ADO ? We can call using Command Objects.
20. What is the different between Microsoft ODBC Driver and Oracle OBDC Driver?
Microsoft ODBC driver will support all the methods and properties of Visual Basic. Where as the Oracle not.
21. What are the Technologies for Accessing Database from Visual Basic?
DAO, Data Control, RDO, ODBCDIRECT, ADO, ODBC API.
Calling Stored Procedures in VB?
1. Calling Simply the Procedure with out Arguments “Call Procedure Name}”
If it is with Arguments Means then
Declare the Query Def qy
Set Qy as New Query def
Qy.SQL = “{Call ProcedureName(?,?,?)}”
qy(0)=val(Txt1.Text)
qy(1)=val(Txt2.Text)
qy(2)=val(Txt3.Text)
Set Rs = Qy.OpenresultSet
Txt(1)=Rs.RdoColumns(0)