Other Library Functions

dbProcedureOpen

function

Library: Database access (OMDB legacy)
Include: omdb.xin

Returns: A specific procedure of type dbProcedure.


Declaration 
define external dbProcedure function 
   dbProcedureOpen                 value     dbDatabase database
                         procedure value     stream     procedure
                   parameter-types read-only integer    parameters optional
                        data-types read-only integer    datatypes  optional
                        data-sizes read-only integer    datasize   optional

Argument definitions

database
is a dbDatabase object representing an open database connection.
procedure
is the name of the stored procedure.
parameters
is a keyed list of the parameter modes used in the procedure.
datatypes
is a keyed list of the SQL data types of the procedure parameters.
datasizes
is a keyed list of the size (expressed as number of digits or number of characters) of the procedure parameters.


Purpose

Use dbProcedureOpen to open a connection to a stored procedure in the database.

Requirements

You must include the following line at the beginning of your OmniMark program: 

  include "omdb.xin"

procedure must:

With some ODBC drivers, you must supply all three procedure parameter description arguments (else external exception OMDB409) if your procedure uses parameters. The procedure parameter description shelves (parameters, datatypes and datasizes) must

The keys may be in a different order.

The parameter types must be valid (else external exception OMDB403). The following macro-defined parameter types are allowed:

Values supplied for datasizes cannot be negative numbers (else external exception OMDB412).

Usage Notes

The key names of output parameters are used to key the "out" dbField parameter in dbProcedureExecute.

The following SQL datatypes are supported by this function:

However, some of these datatypes may not be supported on some databases and ODBC drivers (external exception OMDB501 if not supported).

Database Interface Notes

Example

In this example, a stored procedure that processes a customer purchase transaction is executed in the OmniMark program. The stored procedure, "PurchaseItem", takes four parameters:

  1. CustomerID - a unique value identifying a single customer
  2. ProductID - a unique value identifying a single product
  3. ItemCount - the number of items requested by the customer
  4. InventoryCount - the number of items remaining in inventory after the current sale

The first two parameters are only read by the procedure. The ItemCount parameter is read in the procedure and the total number of items sold to the customer is written into the variable at the end of the procedure. If there are fewer than the requested number of items in inventory, the written value will be less than the initial value. The inventory count is only written to by the procedure and it contains the total number of items remaining in inventory after the sale. The procedure also returns a value. (This type of stored procedure is called a stored function on some databases.) The value returned is the total cost to the customer for the purchase. 

     ; process parameter values
     local stream CustomerID initial { '7734' }
     local stream ProductID  initial { '34-RTS-485643' }
     local stream ItemCount  initial { '47' }
  
     ; local variables
     local dbProcedure purchase-item
     local stream in-val variable
     local dbField out-val variable
     local dbField res-val variable
     local integer types variable initial { SQL_RETURN_VALUE       with key 'RETURN_VALUE',  
                                            SQL_PARAM_INPUT        with key 'CustomerID',  
                                            SQL_PARAM_INPUT        with key 'ProductID',  
                                            SQL_PARAM_INPUT_OUTPUT with key 'ItemCount',  
                                            SQL_PARAM_OUTPUT       with key 'InventoryCount' }
     local integer datatypes variable initial {  SQL_DOUBLE  with key 'RETURN_VALUE',
                                                 SQL_DECIMAL with key 'CustomerID',
                                                 SQL_VARCHAR with key 'ProductID',
                                                 SQL_DECIMAL with key 'ItemCount',
                                                 SQL_DECIMAL with key 'InventoryCount' }
     local integer datasizes variable initial { 15 with key 'RETURN_VALUE',
                                                38 with key 'CustomerID',
                                                50 with key 'ProductID',
                                                38 with key 'ItemCount',
                                                38 with key 'InventoryCount' }
  
     ; open the procedure
     set purchase-item to dbProcedureOpen                 inventory-db
                                                procedure 'PurchaseItem'
                                          parameter-types types
                                               data-types datatypes
                                               data-sizes datasizes
  
     ; set the input values
     set new in-val{ 'CustomerID' } to '7734'
     set new in-val{ 'ProductID' }  to '34-RTS-485643'
     set new in-val{ 'ItemCount' }  to '47'
  
     ; execute the procedure
     dbProcedureExecute purchase-item in in-val out out-val result res-val
  
     ; display the processing results
     output 'Customer %g(CustomerID '  
             || 'requested %g(ItemCount) ' 
             || 'units of %g(ProductID)%n'
     output dbFieldValue out-val{ 'ItemCount' }      
            || ' units were sold%n'
     output dbFieldValue out-val{ 'InventoryCount' } 
            || ' units remaining in inventory%n'
     output 'Total value of the sale was $'        
            || dbFieldValue res-val{'RETURN_VALUE'}     
            || '%n'

Other Library Functions