Calling DB-Library functions

While PowerBuilder provides access to a large percentage of
the features within SQL Server, in some cases you may decide that
you need to call one or more DB-Lib functions directly for a particular
application. PowerBuilder provides access to any Windows DLL by
using external function declarations.

The DB-Lib calls qualify for this type of access. Most DB-Lib
calls require a pointer to a DBPROCESS structure as their first
parameter. If you want to call DB-Lib without reconnecting to the
database to get a DBPROCESS pointer, use the PowerScript DBHandle
function.

DBHandle

DBHandle takes a transaction object as a parameter and returns
a long variable, which is the handle to the database for the transaction.
This handle is actually the DBPROCESS pointer that PowerBuilder
uses internally to communicate with the database. You can use this
returned long value in the SQL Server DLLs and pass it as one of
the parameters in your function.

This example shows how to use DBHandle. Assume a successful
connection has occurred using the default transaction object (SQLCA):

// Define a variable to hold our DB handle.
long    SQLServerHandle

// Go get the handle.
SQLServerHandle = SQLCA.DBHandle( )

// Now that you have the DBPROCESS pointer,
// call the DLL function.
MyDLLFunction( SQLServerHandle, parm1, parm2, ... )

In your DLL, cast the incoming long value into a pointer to
a DBPROCESS structure:

MyDLLFunction( long 1SQLServerHandle,
        parm1_type parm1,
        parm2_type Parm2, ... )

{
DBPROCESS * pDatabase;
pDatabase = (DBPROCESS *)  1SQLServerHandle;
// DB-Lib functions can be called using pDatabase.
}