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DRDA, FDOCA, and SQL Datatype Correspondence

IP.com Disclosure Number: IPCOM000108011D
Original Publication Date: 1992-Apr-01
Included in the Prior Art Database: 2005-Mar-22
Document File: 2 page(s) / 71K

Publishing Venue

IBM

Related People

Fisher, GE: AUTHOR [+2]

Abstract

This article describes a program link to the appropriate datatype representation, that is FDOCA or SQL, based on the DRDA type.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 52% of the total text.

DRDA, FDOCA, and SQL Datatype Correspondence

       This article describes a program link to the appropriate
datatype representation, that is FDOCA or SQL, based on the DRDA
type.

      Each database environment uses SQL type to represent the
supported datatypes.  These datatypes also have DRDA types.  When
column data is requested by a DRDA OS/2* client, the application
server will provide descriptor information which contains the DRDA
type for each column. There is not a one-to-one correspondence
between the DRDA type received and the FDOCA, nor is there a
one-to-one correspondence between FDOCA types and SQL types.  Both
the corresponding FDOCA and SQL type are required for the DRDA OS/2
client to appropriately convert the data, since conversion
information is implied by the FDOCA type.

      A method must be provided for the OS/2 client to establish a n
correspondence between these datatypes.  Also, the conversion
information implied by the FDOCA type must be available to the
client. The problem is summarized into three areas.
      1.  Establish a correspondence between DRDA types and FDOCA
types.
      2.  Establish a correspondence between FDOCA types and SQL
types.
      3.  Provide the client FDOCA to SQL conversion information,
i.e., CCSID.

      The solution is to construct a table which establishes a
correspondence between these types.  Since the DRDA type is received
from the application server by the OS/2 client, this type must be
used as the basic entry into the table. The DRDA types are in
ascending order without gaps. Therefore, a sequential table is built.
The required information for the table is the DRDA lookup type, the
corresponding FDOCA type, SQL type and the CCSID override
informat...