VB Questions (Client Server)

  1. What is difference between datagrid and flexigrid?

    Datagrid – Editable.
    Flexigrid – Non-Editable. (Generally used for Read only purpose.)

  2. What is ADO? What are its objects ?

    ActiveX Data Object. 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.
    Objects are Connection, Record Set, Command, Parameter, field, Error, Property.

  3. 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,

  4. What are two validate with Data Control?

    Data_Validate, Data_Error.

  5. Record set types and Number available in VB?

    3.     1- Dynaset, 0 – Table, 2 – Snap Shot.

  6. Referential Integrity ( Take care By jet database Engine).

    Cascade Delete, Cascade Update – is done setting property of Artibutes.
    DbRelationDeleteCascade,
    DbRelationUpdateCascade.

  7. What are the lock available in Visual Basic?

    2 types of locks. They are 1. Pessimistic – Set Lock Edit property = True (default)
    2. Optimistic - " = False


  8. 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.

  9. 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.

  10. 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.

  11. What are the Technologies for Accessing Database from Visual Basic?

    DAO, Data Control, RDO, ODBCDIRECT, ADO, ODBC API , 0040.

  12. Calling Stored Procedures in VB?

    1. Calling Simply the Procedure with out Arguments

    "    Call ProcedureName}"

    2. 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)

  13. What is MAPI ?

    Messaging Application programing Interface.

  14. Different type of Passing Value?

    By value, By ref, Optional, Param Array.

    Note:- Optional keyword cannot be used while declaring arguments for a function using param array.

  15. What are the different types of error?

    Syntax Errors, Runtime , Logic.

  16. What is Seek Method which type of record set is available this?

    Only in DbOpenTables.
    Syntax: rs.index = "empno"
    rs.seek "=" , 10
    If with our setting the rs.index then run time error will occur.

  17. What is Centralization Error Handling?

    Writing funciton and calling it when error occurs.

  18. Handling Error in Calling chain.

    This will call the top most error where the error is handled.

  19. To connect the Data Control with Back end What are all the properties to be set?

    Data source Name, Record Source Name

  20. How to trap Data Base Error?

    Dim x as RDOError
    X(0).Des
    X(1).Number

  21. What is view Port?

    The area under which the container provides the view of the ActiveX Document is know as a view port.

  22. What methods is used for DBGrid in unbound mode?

    AddData, EditData, Readdata, WriteData.

  23. How to increase the Date corresponding with month,date,year?

    DateSerial(year(Now),Month(Now)+1,1)

    Hour, min, sec, month, year, dateSerial, dateadd, datediff, weekday, datevalue, timeserial,timevalue.


  24. Setting the Cursors.

    Default Cursor – 0
    ODBC Cursor (Client side) – 1
    ServerSide Cursors (More Network traffic) - 2

  25. Cursor management

    Client Batch –     Batch up the Multiple SQL Statements in a single string and Send them to the Server at one time.

  26. What are the record set types?

    RdOpenFowardOnly 0 (Default used only for the read only purpose)
    RdOpenStatic 1
    RdOpenDynamic 2
    RdOpenKeySet 3 (Normally used for the live project)

  27. Diff types of Lock Types?

    RdConcurReadOnly 0 (Default)
    RdConcurLock 1 (Pessimitic Locking)
    RdConcurRowver 2 (Optimistic Lociking)
    RdConcurValues 3
    RdConcurBatch 4

  28. What the RDO Methods and Events?

    Methods Events

    Begin Trans Validate
    Commit Trans Reposition
    Rollback Trans Error
    Cancel Query Complied
    Refresh
    Update Controls
    Update row

  29. What is Static Cursor?

    In ADO Snap Shot is called so.

  30. What is Mixed Cursors?

    Static + Keyset

  31. What is Fire House Cursors?

    Forward Only Some time Updateable

  32. What is DBSqlPassThrough?

    It will By Passing the Jet Query Processor.

  33. What is DBFailError?

    Rolls Back updates if any errors Occurs.

  34. DSN Less Connection?

    "Server=Oracle; Driver={Microsoft ODBC for Oracle};"

  35. What is RdExecDirect?

    Bypasses the Creation of a stored procedure to execute the query. Does not apply to Oracle.

  36. RdoParameter Object RdoParameterConstant

    Direction RdparamInput
    RdparamInputOutput
    RdParamOutput
    Name
    Type
    Value

.

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