Printable View
1)What are different types of Cursors?
Explain me in detail plz.
2)What are diff types of locks?
In some sites-
Four types of locks availbale in ADODB
1.Optimistic
2.pessimistic
3.batch optimistic
4.readonly
In some sites
Forwardonly , lock,adLockUnspecified
What are exact locks,can somebody tell me?
3) What is Z order Precedence?
4) dim X,Y as integer
They ask me X is of which datatype in VB & in VB.net?
I told integer in both Vb & VB.Net,they told me wrong? Whats the ans?
1. Seems a bit of an odd question but I would have thought different types of Cursors means just the different mouse cursors you can have, like the Hand, Hour Glass etc.
2. Not sure to be honest
3. Z order is the '3D' order of controls on a form, so by setting the Z order you can choose which controls appear in front of each other.
4. Not sure about VB6 but in VB.NET then X definitely is an Integer.
For the first two questions I would suggest that you read this article.
I do not understand the third question, in what context would there be a z-order precedence? The Z-order normally just determents which controls are above other controls on a WinForm.
For the forth question, they will both be integers in VB.Net, but in VB6 and earlier X would be a Variant while Y would be an integer. In VB6 you had to specify the type for each variable and if you didn't they would become Variants. Dim X As Integer, Y As Integer.
1.) en.wikipedia.org/wiki/Cursor_(databases) First question I think is dealing with cursors used in databases (most likely the question is dealing with what they are, different types, and how they would be utilized in SQL programming)
2.) en.wikipedia.org/wiki/Lock_(database) Believe the second question is dealing with database locks (What they are, how to solve them, how to prevent them)
lol I thought asking which types of Mouse Cursors were available was a bit odd :D
1. Refers to what record you are on in the database and the editing state of it and how you can "move" the cursor throughout the dataset:
adOpenForwardOnly 0 Default for Server-Side Recordsets
You can only move forward.
adOpenKeySet -You can move forward and backward modify, delete records
adOpenDynamic -You can move forward and backward Insert, Modify and delete
adOpenStatic -Default for "Client-side" recordsets. You cannot see changes by others, but you can move forward and backward through the records.
2. Record locking is basically how data is "locked" for editing/reading etc when it is being modified on another computer.
In access under options / Advanced you have 3 options:
No Locking - doesn't lock a record - if it is edited in 2 places symataiously (can't spell :P) the FIRST edit will save then the SECOND edit will over wright the first
All Records - locks an entire table for editing - so only one person can modify data at a time in a table
Edited Record - This should be the method that is ALWAYS used - it means that people can edit records in the table except for records being modified by someone else on another machine
Optimistic - Locks the record while it is being saved (No Locking)
pessimistic - Locks the record while it is being edited (Edited Record)
batch optimistic - Locks a group of records when they are being modified in a batch method ... eg an update statement
readonly - same as All Records makes all TABLES used (that are editable) by the recordset readonly while the data is being edited
Forwardonly - are you sure that this isn't a cursor?:S
adLockUnspecified - not sure
3. Zorder basically determines what controls are "on top" of others
4. in .net dim X,Y as integer will make both int's
in vb6 Y will be an int and x will be a variant
Hope this explains everything
Kris