MDAC 2.5 SDK - ADO

Microsoft OLE DB Provider for SQL Server

See Also

The Microsoft OLE DB Provider for SQL Server, SQLOLEDB, allows ADO to access Microsoft SQL Server.

Connection String Parameters

To connect to this provider, set the Provider argument to the ConnectionString property to:

SQLOLEDB

This value can also be set or read using the Provider property.

Typical Connection String

A typical connection string for this provider is:

"Provider=SQLOLEDB;Data Source=serverName;Initial Catalog=databaseName; User ID=userName;Password=userPassword;"

Consisting of these keywords:

Provider-Specific Connection Parameters

The provider supports several provider-specific connection parameters in addition to those defined by ADO. As with the ADO connection properties, these provider-specific properties can be set via the Properties collection of a Connection or can be set as part of the ConnectionString.

Command Object Usage

SQLOLEDB accepts an amalgam of ODBC, ANSI, and SQL Server-specific Transact-SQL as valid syntax. For example, the following SQL statement uses an ODBC SQL escape sequence to specify the LCASE string function:

SELECT customerid={fn LCASE(CustomerID)} FROM Customers
  

LCASE returns a character string, converting all uppercase characters to their lowercase equivalents. The ANSI SQL string function LOWER performs the same operation, so the following SQL statement is an ANSI equivalent to the ODBC statement presented above:

SELECT customerid=LOWER(CustomerID) FROM Customers
  

SQLOLEDB successfully processes either form of the statement when specified as text for a command.

Stored Procedures

When executing a SQL Server stored procedure using a SQLOLEDB command, use the ODBC procedure call escape sequence in the command text. SQLOLEDB then uses the remote procedure call mechanism of SQL Server to optimize command processing. For example, the following ODBC SQL statement is the preferred command text over the Transact-SQL form:

ODBC SQL

{call SalesByCategory('Produce', '1995')}
  

Transact-SQL

EXECUTE SalesByCategory 'Produce', '1995'
 

Recordset Behavior

SQLOLEDB cannot use SQL Server cursors to support the multiple-rresult generated by many commands. If a consumer requests a recordset requiring SQL Server cursor support, an error occurs if the command text used generates more than a single recordset as its result.

Scrollable SQLOLEDB recordsets are supported by SQL Server cursors. SQL Server imposes limitations on cursors that are sensitive to changes made by other users of the database. Specifically, the rows in some cursors cannot be ordered, and attempting to create a recordset using a command containing an SQL ORDER BY clause can fail.

Dynamic Properties

The Microsoft OLE DB Provider for SQL Server inserts several dynamic properties into the Properties collection of the unopened Connection, Recordset, and Command objects.

The tables below are a cross-index of the ADO and OLE DB names for each dynamic property. The OLE DB Programmer's Reference refers to an ADO property name by the term, "Description." You can find more information about these properties in the OLE DB Programmer's Reference. Search for the OLE DB property name in the Index or see Appendix C: OLE DB Properties.

Connection Dynamic Properties

The following properties are added to the Connection object's Properties collection.

Recordset Dynamic Properties

The following properties are added to the Recordset object's Properties collection.

Command Dynamic Properties

The following properties are added to the Command object's Properties collection.

See Also   For specific implementation details and functional information about the Microsoft SQL Server OLE DB Provider, consult the OLE DB Provider for SQL Server documentation in the MDAC SDK.