ActiveX Data Objects (ADO) with Visual Basic

Connections¶

An ADO connection string typically has the following format: Provider=provider;Data Source=data-source;User ID=userid;Password=password

Where provider is one of the following.

Database	Provider
Access	Microsoft.Jet.OLEDB.4.0
DB2	IBMDADB2.1
Oracle	MSDAORA.1 or OraOLEDB.Oracle.1
SQL Server	SQLOLEDB.1
All	MSDASQL.1 (MS OLE DB provider for ODBC)

Recordsets¶

Cursor Types¶

Use forward-only cursors wherever possible. If a forward-only cursor cannot be used, then use a Static cursor instead.

Cursor Location¶

Use a client-side cursor for SQL statements that return records, and a server-side cursor for everything else.

Lock Types¶

Lock Type	Characteristics
adLockBatchOptimistic	Rows are locked only long enough to write updates. Used with client-side cursors.
adLockOptimistic	Rows are locked only long enough to write updates. Used with client-side cursors.
adLockPessimistic	Only the current row in the recordset is locked till (1) cursor is moved to another row or (2) the recordset is closed. Used with server-side cursors.
adLockReadOnly	Rows are never locked. Used with client or server side cursors.