ADO (ActiveX Data Objects) are used primarily by ASP programmers for manipulating data - that is, retrieving it from data stores to display on web pages, and allowing users to insert or modify data in data stores.
ADO can also be used as a method of passing DDL (Data Defintion Language) commands to create, drop and alter tables and their fields within databases, but what about creating a new Access database, for example, or other schema based activities?
ADOX (ADO Extensions) is the tool for this. The ADOX object model starts with the Catalog object, which is the top-level object. The Catalog object contains a number of objects as properties, each of which are collections. (For example, the Tables property of the Catalog object is a collection of Table objects.) These Catalog object properties include:
- Tables
- Groups
- Users
- Procedures
- Views
The Catalog object represents the top level object, schema information about a data store. Here's how to use it to create a new Access .mdb file and add a table with a primary key.
<%
'Const adVarWChar = 202
'Const adInteger = 3
'The above are from adovbs.inc and are the ADO Constants
'for the two datatypes used in this example.
Dim objADOXDatabase
'Instantiate a Catalog object
Set objADOXDatabase = CreateObject("ADOX.Catalog")
'Use the Create method, passing the Datasource Provider
'and full path and file name as parameters
objADOXDatabase.Create "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=PathToDatabasecustomers.mdb"
'The database now exists...
'Create a database table and name it
Dim objFirstTable
Set objFirstTable = CreateObject("ADOX.Table")
objFirstTable.Name = "Customers"
'CustomerID will be of datatype adInteger, for which the ADO Constant is 3
objFirstTable.Columns.Append "CustomerID", 3
'CustomerName is of datatype adVarWChar, for which the ADO Constant is 202.
'The field size is 30 characters
objFirstTable.Columns.Append "CustomerName", 202, 30
'Create a key, passing first the name of the key,
'then the type (1 = primary key),
'then the column on which it is created
objFirstTable.Keys.Append "PK_CustomerID", 1, "CustomerID"
'Add the database table to the database
objADOXDatabase.Tables.Append objFirstTable
response.write "Database created"
'Clean up...
Set objFirstTable = Nothing
Set objADOXDatabase = Nothing
%>
