Example: Visual Basic - Access and return data by a call to a stored procedure

Visual Basic is able to call external functions that are found in DLLs. Since all ODBC drivers are DLLs, Visual Basic can be used to code directly to the ODBC APIs. By coding directly to the ODBC APIs a Visual Basic application can call an iSeries™ server stored procedure and return result values.

   ' This statement will drop an existing stored procedure
 szDropProc = "drop procedure apilib.partqry2"
 
 
    '* This statement is used to create a  stored procedure
    '* Unless the
    '* procedure is destroyed, this statement need never be re-created
 szCreateProc = "CREATE PROCEDURE APILIB.PARTQRY2 (INOUT P1 INTEGER,"
 szCreateProc = szCreateProc & "INOUT P2 INTEGER)"
 szCreateProc = szCreateProc & "EXTERNAL NAME APILIB.SPROC2 LANGUAGE RPG GENERAL"
 
 
    '*  Allocate statement handle
 rc = SQLAllocHandle(SQL_HANDLE_STMT, ghDbc, hStmt) 
 If rc <> SQL_SUCCESS Then
      Call DisplayError(rc, "SQLAllocStmt failed.")
      Call DspSQLError(henv, SQL_NULL_HDBC, SQL_NULL_HSTMT)
 End If
   '* Drop the old Procedure
 rc = SQLExecDirect(hstmt, szDropProc, SQL_NTS)
 
    ' Create the new Procedure
 rc = SQLExecDirect(hstmt, szCreateProc, SQL_NTS)
 If rc <> SQL_SUCCESS And rc <> SQL_SUCCESS_WITH_INFO Then
      Call DisplayError(rc, "SQLCreate failed.")
      Call DspSQLError(henv, hdbc, hstmt)
 End If

    '* This statement will be used to call the stored procedure
    szStoredProc = "call partqry2(?, ?)"
   '* Prepare the stored procedure call statement
 
    rc = SQLPrepare(hstmt, szStoredProc, Len(szStoredProc))
    If rc <> SQL_SUCCESS And rc <> SQL_SUCCESS_WITH_INFO Then
        Call DisplayError(rc, "SQLPrepare failed.")
        Call DspSQLError(henv, hdbc, hstmt)
    End If

 
  'Bind the parameters for the stored procedure
     rc = SQLBindParameter(hstmt, 1, SQL_PARAM_INPUT, SQL_C_LONG, _
                SQL_INTEGER, lLen1, 0, sFlag, lLen1, lCbValue)
 
     If rc <> SQL_SUCCESS Then
        Call DisplayError(rc, "Problem binding parameter ")
     End If
 
     rc = SQLBindParameter(hstmt, 2, SQL_PARAM_INPUT, SQL_C_SLONG, _
                        SQL_INTEGER, 4, 0, lPartNumber, lLen2, lCbValue)
 
     If rc <> SQL_SUCCESS Then
        Call DisplayError(rc, "Problem binding parameter ")
     End If

   rc = SQLExecute(hstmt)
   If lRc <> SQL_SUCCESS Then
          ' Free the statement handle for repeated processing
               rc = SQLFreeHandle(
           Call DspSQLError(henv, hdbc, hstmt)
   End If
   rc = SQLFetch(hstmt)
   If rc = SQL_NO_DATA_FOUND Then
          mnuClear_Click               'Clear screen
          txtPartNumber = lPartNumber 'Show the part number not found
          Call DisplayMessage("RECORD NOT FOUND")
          .
          .
        Else
      'Get Description
            rc = SQLGetData(hstmt, 2, SQL_C_CHAR, sSDescription, _
                            25, lcbBuffer)
            'Get Quantity. SQLGetLongData uses alias SQLGetData
            rc = SQLGetLongData(hstmt, 3, SQL_C_SLONG, lSQuantity, _
                                Len(lSQuantity), lcbBuffer)
            'Get Price. SQLGetDoubleData uses alias SQLGetData
            rc = SQLGetDoubleData(hstmt, 4, SQL_C_DOUBLE, dSPrice, _
                                    Len(dSPrice), lcbBuffer)
            'Get Received date
            rc = SQLGetData(hstmt, 5, SQL_C_CHAR, sSReceivedDate, _
                            10, lcbBuffer)
            txtDescription = sSDescription  'Show description
            txtQuantity = lSQuantity          'Show quantity
            txtPrice = Format(dSPrice, "currency")   'Convert dSPrice to
            txtReceivedDate = CDate(sSReceivedDate)  'Convert string to d
            Call DisplayMessage("Record found")
      End If