Local data access solution
problem
What you need is a simple, consistent application programming interface (API), enabling the application to access and modify a wide variety of data sources. The data source may be as simple as text files, or it is possible to complicate as a bunch of heterogeneous databases or some of the data that is not yet set. In addition, the API should not preset the way to access and operate the data source.
Although these requirements are proposed, typical data sources still need to support an open database connection (ODBC) standard relational database, and can operate it by using commands written in structure query language (SQL).
Microsoft provides the overall solution provided by this issue is OLE DB, which is a set of component object model (COM) interfaces that provide uniform access to different information sources. But the design of the OLE DB application programming interface is to provide optimization functions for a variety of applications, which cannot meet the simplified requirements.
The API you need should be a bridge that connects to applications and OLE DBs, which is ActiveX® Data Objects (ADO).
solution
The ADO defines the programming model, that is, accesses and updates the order of activity necessary. The programming model summarizes all the features of the ADO.
The programming model means the object model, the "Object" group that responds to and executes the programming model. The object has a "method", the method performs the operation of the data; the object has "attribute", the property indicates certain characteristics of the data or controls the behavior of certain object methods.
As an object is "event", the event is a notification that has occurred or will occur.
