Command Syntax
The SQL Native Client OLE DB provider recognizes command syntax specified by the DBGUID_SQL macro. For the SQL Native Client OLE DB provider, the specifier indicates that an amalgam of ODBC SQL, SQL-92, and Transact-SQL is 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 SQL-92 string function LOWER performs the same operation, so the following SQL statement is a SQL-92 equivalent to the ODBC statement presented above:
SELECT customerid=LOWER(CustomerID) FROM Customers
The SQL Native Client OLE DB provider processes either form of the statement successfully when specified as text for a command.
Stored Procedures
When executing a SQL Server stored procedure using a SQL Native Client OLE DB provider command, use the ODBC CALL escape sequence in the command text. The SQL Native Client OLE DB provider then uses the remote procedure call mechanism of SQL Server to optimize command processing. For example, the following ODBC SQL statement is preferred command text over the Transact-SQL form:
ODBC SQL
{call SalesByCategory('Produce', '1995')}Transact-SQL
EXECUTE SalesByCategory 'Produce', '1995'