1. ActiveX Data Objects (ADO)
Performs same functions as DAO with following improvements:
Simpler command set
Faster execution (sometimes)
Uses less memory
Consumes less disk space
Supports any database to which Access can connect

2. ActiveX Data Objects (ADO)
Connection object
Establishes a link to a database
ADO objects should be prefixed with ADODB
Set statement is optional when assigning values to ADO objects, if you use the New keyword
Example:
Connection property of CurrentProject stores a reference to the current database.
Dim cnn As New ADODB.Connection
Cnn.Open CurrentProject.Connection OR
Set cnn = CurrentProject.Connection

3. ActiveX Data Objects (ADO)
Opening a recordset
Arguments
Table or query
SQL statements may be embedded
Database connection
Usually the current one stored in the Connection object variable
Cursor types
Lock types

4. ActiveX Data Objects (ADO)
Cursor types
adOpenForwardOnly
Read only recordset with ability to scroll through the records in a forward direction only
adOpenKeyset
Requests a dynaset that can be updated
adOpenDynamic
Updateable, but not available for Jet databases
adOpenStatic
Read only where updates are not visible
OpenKeyset is the type to use

5. ActiveX Data Objects (ADO)
Lock types
adLockReadOnly
No changes allowed
adLockPessimistic
Lock the record immediately upon entering
adLockOptimistic
Attempt to lock the record when the record is saved
adLockBatchOptimistic
Used for batch updating
Prefer optimistic locking

6. ActiveX Data Objects (ADO)
Update method
Changes saved using Update, moving to another record or closing the recordset
In DAO, only Update method saves the changes
Find method
Replaces FindFirst, FindLast, etc. from DAO
Update method in either case is highly recommended

7. ActiveX Data Objects (ADO)
Edit method
ADO automatically opens in an edit mode
DAO requires Edit method
Both use AddNew and Delete; most other methods are similar to DAO

8. ADO or DAO? ADO is a generic interface to multiple database providers
Useful for building client/server and web applications
DAO is best performer for Jet (Access) databases
ADO has to retrieve info about the database before it can communicate with it
ADO has security shortcomings for Jet databases
ADO good for SQL server, Oracle
Microsoft is not going to upgrade DAO any more.
Security: When creating new users and groups programmatically, ADO does not return the personal identifier for the new user or group. If you lose the file that stores the personal identifiers, you may not be able to recreate it.