Encyclopedia > ADO

  Article Content

ADO

Microsoft ADO (ActiveX Data Objects) is a Component object model object for accessing data sources. It provides a layer between programming languages and databases, which allows a developer to write programs which access data, without knowing how the database is implemented. No knowledge of SQL is required to access a database when using ADO, although one can use ADO to execute arbitrary SQL commands. The disadvantage of this is that this introduces a dependency upon the database.

It is positioned as a successor to Microsoft's earlier object layers for accessing data sources, including RDO[?] (Remote Data Objects) and DAO[?] (Data Access Objects).

ADO consists of several top-level objects:

Connection (represents the connection to the database)
Recordset (represents a set of database records)
Command (represents a SQL command)
Record (represents a set of data, typically from a source other than a database)
Stream (represents a stream of data, as from a text file or web page)
Error (stores errors)
Field (represents a database field)
Parameter (represents a SQL parameter)
Property (stores information about objects)

ADO is used in conjunction with a high-level language, such as VBScript in an ASP environment. Here is an ASP example using ADO to select the "Name" field, from a table called "Phonebook", where a "PhoneNumber" was equal to "555-5555".

 dim myconnection, myrecordset, name
 set myconnection = server.createobject("ADODB.Connection")
 set myrecordset = server.createobject("ADODB.Recordset")

 myconnection.open mydatasource
 myrecordset.open "Phonebook", myconnection
 myrecordset.find "PhoneNumber = '555-5555'"
 name = myrecordset.fields.item("Name")
 myrecordset.close
 
 set myrecordset = nothing
 set myconnection = nothing
 
This is equivalent to the following ASP code, which uses plain SQL, instead of the functionality of the Recordset object:

 dim myconnection, myrecordset, name
 set myconnection = server.createobject("ADODB.connection")
 myconnection.open mydatasource
 set myrecordset = myconnection.execute("SELECT Name FROM Phonebook WHERE PhoneNumber = '555-5555'")
 name = myrecordset(0) 
 myrecordset.close
 
 set myrecordset = nothing
 set myconnection = nothing



All Wikipedia text is available under the terms of the GNU Free Documentation License

 
  Search Encyclopedia

Search over one million articles, find something about almost anything!
 
 
  
  Featured Article
Northwest Harbor, New York

... area of 41.7 km² (16.1 mi²). 37.6 km² (14.5 mi²) of it is land and 4.1 km² (1.6 mi²) of it is water. The total area is 9.81% water. ...

 
 
 
This page was created in 42.8 ms