MS SQL Server/VB6 to Oracle 8i using OBDC

Question

OMW,
I presently connect to MS SQL in Visual Basic 6.0 using ODBC. I
would like to connect to Oracle in the same manner. Does the OMW
do this, and if so are there any things I should know before
attempting to use it in this application? I have purchased and
installed a trial version of Oracle 8i, but I am experiencing
some slight difficulties in the way Oracle handles Resultsets
(RDO Components) compared to MS SQL.
thanks
g
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Answer 1

Gary,
There is some information in the faq (reproduced below), showing
how the application may not need to be changed.
Some of the functionality provided by the intersolve driver is
now available in the oracle 8.1.5.3 odbc driver.
Turloch
Oracle Migration Workbench team
from the faq (shipped with the workbench):
How are result sets/dynasets returned to the calling program?
The Oracle Migration Workbench parser adds an extra argument
of type REF CURSOR for result sets/dynasets. This type is
understood and can be
manipulated by both PL/SQL and Oracle JDBC. Oracle8 release
8.0.5 ODBC drivers support REF CURSORs which means that the
additional argument must
be explicitly handled by the application, and the client
application code must be changed. However, some third-party
vendors such as Intersolv supply ODBC
drivers for Oracle that support REF CURSORs and can, in
addition, implicitly make use of REF CURSORs for using result
sets/dynasets. Therefore, no
change is required in the client application code. This is
illustrated in the following examples of an MS SQL Server stored
procedure and its equivalent Oracle
package and stored procedure as generated by the Oracle
Migration Workbench parser.
MS SQL Server Stored Procedure
CREATE PROCEDURE byroyalty
AS
select au_id from titleauthor
GO
Oracle8i Package and Stored Procedure
PACKAGE BYROYALTYPkg AS
TYPE RT1 IS RECORD (
au_id titleauthor.au_id%TYPE
TYPE RCT1 IS REF CURSOR RETURN RT1;
END;
PROCEDURE byroyalty(
RC1 IN OUT byroyaltyPkg.RCT1)
AS
StoO_selcnt INTEGER;
StoO_error INTEGER;
StoO_rowcnt INTEGER;
StoO_errmsg VARCHAR2(255);
StoO_sqlstatus INTEGER;
BEGIN
OPEN RC1 FOR
SELECT au_id FROM titleauthor;
END byroyalty;
The following example illustrates the typical ODBC code used
by Intersolv to call the above MS SQL Server stored procedure.
This code also works for the
above Oracle8i package and stored procedure. Note that error
handling must be added in a real application:
SQLPrepare(...,'{call byroyalty()}',...)
SQLExecute()
SQLBindCol()
SQLFetch()
Comments:
SQLPrepare(...,'{call byroyalty()}',...) is the ODBC SQL
syntax used to execute stored procedures.
SQLExecute()executes the stored procedure.
SQLBindCol()assigns storage for result column 1 in the
result set (au_id).
SQLFetch() fetches the first record from the result set
generated by the stored procedure.
The following examples illustrate how to call the above MS
SQL Server stored procedure with result sets/dynasets in Visual
Basic using DAO and RDO on
top of ODBC. This code works for Oracle8i packages and
stored procedures if you use an Intersolv ODBC driver to
understand Oracle REF CURSORs.
DAO
Private Sub Command2_Click()
Dim sSql As String
sSql = "{call byroyalty()}"
'In Oracle ODBC driver use refcusor argument to get
result set
Set rCustomers = dbsServer.OpenRecordset(sSql,
dbOpenDynamic)
Text4 = rCustomers.Fields(0)
theend:
End Sub
Please note, this example assumes that a DAO connection has
been set up already.
RDO
Private Sub Command1_Click()
StrSql = "{call byroyalty}"
'in oracle odbc driver uses refcusor argument to get
result set
Set Ps = connx1.CreatePreparedStatement("PsTest",
StrSql)
Set Rs = Ps.OpenResultSet(rdOpenStatic
Text3 = Rs!au_id
Rs.Close
End Sub
Please note, this example assumes that an RDO connection has
been set up already.
Gary (guest) wrote:
: OMW,
: I presently connect to MS SQL in Visual Basic 6.0 using ODBC. I
: would like to connect to Oracle in the same manner. Does the
OMW
: do this, and if so are there any things I should know before
: attempting to use it in this application? I have purchased and
: installed a trial version of Oracle 8i, but I am experiencing
: some slight difficulties in the way Oracle handles Resultsets
: (RDO Components) compared to MS SQL.
: thanks
: g
Oracle Technology Network
http://technet.oracle.com
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