ActiveX Data Objects (ADO)
Definition - What does ActiveX Data Objects (ADO) mean?
ActiveX Data Objects (ADO) is a collection of software components providing a programmatic interface to access the data sources from client applications. ADO acts as a layer to access any data store in a generic way from the application code. It eliminates the need to possess the knowledge of database implementation and reduces the complexity of dealing with the low level code needed to handle the data.
Released in 1996, activeX data object (ADO) originated from the concept of RDO (remote data object) and DAO (data access object). One of the constituents of MDAC (Microsoft data access components), ADO and other MDAC constituents provides a framework of components used by client applications to access SQL, semi-structured and legacy data stores.
ADO.NET is an advanced data access technology designed to work in the .NET environment and is based on the disconnected model for data access. While ADO uses COM (Component Object Model) technology for providing data access service from unmanaged code, ADO.NET depends on managed providers of the CLR (Common Language Runtime) of the .NET framework.
Techopedia explains ActiveX Data Objects (ADO)
ADO uses an OLEDB provider for connecting to the data sources and accessing data. OLEDB is a component based programmatic interface provided to interact with different data sources. These data sources can be both relational and non-relational databases such as object databases, web pages, spreadsheets or e-mail messages. Prior to OLEDB and ADO, ODBC (open database connectivity) was the popular model used in applications across platforms.
The object model of ADO contains four collections of twelve objects. The different collections are fields, properties, parameters and errors. Each collection consists of the following twelve objects:
- Connection - for connecting to data source through OLE DB
- Command - for sending an instruction (SQL query or stored procedure) to data provider
- Recordset - a group of records representing the data
- Immediate - a recordset locked in optimistic or pessimistic way
- Batch - for committing or doing a rollback database transaction
- Transaction - the database transaction
- Record - a set of fields
- Stream - for reading and writing a stream of bytes
- Parameter - for changing the functionality
- Field - a column in the database
- Property - the ability of OLEDB provider
- Error - the error faced by the OLEDB provider during its execution
ADO 2.8 is the latest version and has the following features:
- Components: These are used for data access and manipulation from a variety of sources to offer benefits like ease of use, faster access, low memory overhead and a small disk footprint.
- ADO MD (MultiDImensional): This is used to access multidimensional data like CubeDef and CellSet objects.
- RDS (Remote Data Services): This is for retrieval and update of data in the server from a client in a single transaction.
- ADOX (ADO Extensions): This is an additional set of components used to create and maintain objects related to schema (tables or procedures) and security (user and group).