Take the following dummy stored procedure:

CREATE PROCEDURE test 
  @cName varchar(30),
  @iResult int OUTPUT
AS

select * from wws_customers where company like @cName

Set @iResult = 10
GO

The official way is the following:

oSQL = CREATEOBJECT("wwADOSql")
* oSQL.nCodepage=65001  && UTF-8
oSQL.Connect("Provider=sqloledb;Data Source=(local);Initial Catalog=WebStore;Integrated Security=SSPI")

oSQL.AddParameter("W%","cName")
oSQL.AddParameter(0,"iResult","OUT")  && Output parameter
lnResult = oSQL.CallStoredProcedure("test")

if lnResult = -1
   ? oSQL.cErrorMsg
   RETURN && Errro
ENDIF

*** Retrieve a parameter
lnResultValue = oSQL.oParameters["iResult"].Value

*** Cursor returned from the SELECT
BROWSE

The above is the most effective way and gives you the most control over parameter types. You can actually specify each parameters type and width, size etc.

You can also use Visual FoxPro SQL Passthrough syntax like the following:

cName = "W%"
iResult = 0
oSQL.CallStoredProcedure("exec TestNoOutParms ?cName,?@iResult")
? iResult
? o.Parameters["iResult"].Value

Note the following:

• Parameters in the parameter object are case sensitive
  
• If you use VFP style syntax do not set the llStoredProcedure parameter in Execute or ExecuteNonQuery
  
• Only set the llStoredProcedure parameter if you are calling using the first syntax (Proc name and AddParameter() calls)