You can create tables using MGD_ID as the column type to represent RFID tags, for example:

Example 1. Using the MGD_ID column type:

CREATE TABLE Warehouse_info (
             Code          MGD_ID,
             Arrival_time  TIMESTAMP, 
             Location      VARCHAR2(256);
             ...); 

SQL*Plus command:

describe warehouse_info;

Result:

Name                                      Null?    Type
----------------------------------------- -------- ----------------------------
CODE                                      NOT NULL MGDSYS.MGD_ID
ARRIVAL_TIME                                       TIMESTAMP(6)
LOCATION                                           VARCHAR2(256)

There are several ways to construct MGD_ID objects:

• Constructing an MGD_ID Object (SGTIN-64) Passing in the Category ID and a List of Components

• Constructing an MGD_ID object (SGTIN-64) and Passing in the Category ID_ the Tag Identifier_ and the List of Additional Required Parameters

• Constructing an MGD_ID object (SGTIN-64) and Passing in the Category Name_ Category Version (if null_ then the latest version is used)_ and a List of Components

• Constructing an MGD_ID object (SGTIN-64) and Passing in the Category Name and Category Version_ the Tag Identifier_ and the List of Additional Required Parameters

This example shows how to populate the WAREHOUSE_INFO table by inserting each MGD_ID object into the table along with the additional column values:

call DBMS_MGD_ID_UTL.set_proxy('example.com', '80');

call DBMS_MGD_ID_UTL.refresh_category
  (DBMS_MGD_ID_UTL.get_category_id('EPC', NULL));

INSERT INTO WAREHOUSE_INFO (code, arrival_time, location)
   values (MGDSYS.MGD_ID ('EPC',
                          NULL,
                          'urn:epc:id:sgtin:0037000.030241.1041970',
                          null
                         ),
           SYSDATE,
           'SHELF_123');

INSERT INTO WAREHOUSE_INFO (code, arrival_time, location)
  values (MGDSYS.MGD_ID ('EPC',
                         NULL,
                         'urn:epc:id:sgtin:0037000.053021.1012353',
                         null
                        ),
          SYSDATE,
          'SHELF_456');
INSERT INTO WAREHOUSE_INFO (code, arrival_time, location)
  values (MGDSYS.MGD_ID ('EPC',
                         NULL,
                         'urn:epc:id:sgtin:0037000.020140.10174832',
                         null
                        ),
          SYSDATE,
          'SHELF_1034');

COMMITT;
call DBMS_MGD_ID_UTL.remove_proxy();

There are three ways to query on MGD_ID column type.

• Query the MGD_ID column type. Find all items with item reference 030241.

  SELECT location, wi.code.get_component('itemref') as itemref, 
                   wi.code.get_component('serial') as serial 
  FROM warehouse_info wi WHERE wi.code.get_component('itemref') = '030241';
  
  LOCATION       |ITEMREF   |SERIAL
  ---------------|----------|----------
  SHELF_123      |030241    |1041970
  

• Query using the member functions of the MGD_ID ADT. Select the pure identity representations of all RFID tags in the table.

  SELECT wi.code.format(null,'PURE_IDENTITY')
     as PURE_IDENTITY FROM warehouse_info wi;
  
  PURE_IDENTITY
  -------------------------------------------------------------------------------
  urn:epc:id:sgtin:0037000.030241.1041970
  urn:epc:id:gid:0037000.053021.1012353
  urn:epc:id:sgtin:0037000.020140.10174832
  

  See Using the get_component Function with the MGD_ID Object for more information and see Table 25-3 for a list of member functions.

The get_component function is defined as follows:

MEMBER FUNCTION get_component(component_name IN VARCHAR2)
   RETURN VARCHAR2 DETERMINISTIC,

Each component in a identity code has a name. It is defined when the code type is registered.

The get_component function takes the name of the component, component_name as a parameter, uses the metadata registered in the metadata table to analyze the identity code, and returns the component with the name component_name.

The get_component function can be used in a SQL query. For example, find the current location of the coded item for the component named itemref; or, in other words find all items with the item reference of 03024. Because the code tag has encoded itemref as a component, you can use this SQL query:

SELECT location,
       w.code.get_component('itemref') as itemref,
       w.code.get_component('serial')  as serial
FROM   warehouse_info w
       WHERE  w.code.get_component('itemref')  = '030241';

LOCATION       |ITEMREF   |SERIAL
---------------|----------|----------
SHELF_123      |030241    |1041970

See Table 25-3 for a list of other member functions.

RFID readers read the bit strings stored in the tags. The tag data and other information, such as the reader ID and the time stamp, first go through an edge server to be processed, normalized, and preliminarily filtered. Then, in many application scenarios, the information must be persistently stored and later on be retrieved. The Oracle Database understands the code structures representations of various EPC tags as described in Table 25-1 because these code representation schemes defined in the EPC Standard are preregistered. This gives the Oracle Database the ability to understand all the EPC code schemes and parse various tag representations into fields. Users can also register their own coding structures for the identity codes that use other encoding technologies. In this way the system is extensible.

As mentioned in Identity Concepts, each of the EPCGlobal tag schemes (GID-96, SGTIN-64, SGTIN-96, and so on) has various representations with the most often used being BINARY, TAG_URI, and PURE_IDENTITY.

Some representations contain all the information about the tag (BINARY and TAG_URI), while representations contain partial information (PURE_IDENTITY). It is therefore possible to translate a tag from it's TAG_URI to it's PURE_IDENTITY representation, but it is not possible to translate in the other direction (PURE_IDENTITY to TAG_URI) without supplying more information, namely the filter value.

One MGD_ID constructor takes in four fields, the category name (such as EPC), the category version, the tag identifier (for EPC, the identifier must be in a representation previously described), and a parameter list for any additional parameters required to parse the tag representation. For example, this code creates an MGD_ID object from its BINARY representation.

SELECT MGD_ID 
   ('EPC',
    null,
    '1001100000000000001000001110110001000010000011111110011000110010',
    null
   )
   AS NEW_RFID_CODE FROM DUAL;

NEW_RFID_CODE(CATEGORY_ID, COMPONENTS(NAME, VALUE))
--------------------------------------------------------------------------------
MGD_ID ('1', 
        MGD_ID_COMPONENT_VARRAY(MGD_ID_COMPONENT('filter', '3'), 
        MGD_ID_COMPONENT('schemes', 'SGTIN-64'), 
        MGD_ID_COMPONENT('companyprefixlength', '7'), 
        MGD_ID_COMPONENT('companyprefix', '0037000'), 
        MGD_ID_COMPONENT('companyprefixindex', '1'), 
        MGD_ID_COMPONENT('serial', '1041970'), 
        MGD_ID_COMPONENT('itemref', '030241')
       )
      )

For example, an identical object can be created if the call is done with the TAG_URI representation of the tag as follows with the addition of the value of the filter value:

SELECT MGD_ID ('EPC',
                null,
                'urn:epc:tag:sgtin-64:3.0037000.030241.1041970',
                null
              )
  as NEW_RFID_CODE FROM DUAL;

NEW_RFID_CODE(CATEGORY_ID, COMPONENTS(NAME, VALUE))
--------------------------------------------------------------------------------
MGD_ID ('1', 
        MGD_ID_COMPONENT_VARRAY (
         ( MGD_ID_COMPONENT('filter', '3'), 
           MGD_ID_COMPONENT('schemes', 'SGTIN-64'), 
           MGD_ID_COMPONENT('companyprefixlength', '7'), 
           MGD_ID_COMPONENT('companyprefix', '0037000'), 
           MGD_ID_COMPONENT('serial', '1041970'), 
           MGD_ID_COMPONENT('itemref', '030241')
         )
       )

Another useful feature of the Identity Code package is the ability to encode tag data into predefined representations. For example, a warehouse wants to send certain inventory to a retailer, but first it wants to send an invoice that tells the retailer what inventory to expect. The invoice can be a list of pure identity URIs that the warehouse intends to send. If all the inventory in the WAREHOUSE_INFO table is to be sent, this example constructs the desired URIs:

SELECT wi.code.format (null,'PURE_IDENTITY') 
  as PURE_IDENTITY FROM warehouse_info wi;

PURE_IDENTITY
--------------------------------------------------------------------------------
urn:epc:id:sgtin:0037000.030241.1041970
urn:epc:id:gid:0037000.053021.1012353
urn:epc:id:sgtin:0037000.020140.10174832

The Identity Code package can decode tag representations into MGD_ID objects and encode these objects into tag representations. These two steps can be combined into one step using the MGD_ID.translate function. Static translation allows for the conversion of an RFID tag from one representation to another. For example:

SELECT MGD_ID.translate ('EPC',
                         null,
                         'urn:epc:id:sgtin:0037000.030241.1041970',
                         'filter=3;scheme=SGTIN-64',
                         'BINARY'
                        )
  as BINARY FROM DUAL;

BINARY
--------------------------------------------------------------------------------
1001100000000000001000001110110001000010000011111110011000110010

In this example, the binary representation contains more information than the pure identity representation. Specifically, it also contains the filter value and in this case the scheme value must also be specified to distinguish SGTIN-64 from SGTIN-96. Thus, the function call must provide the missing filter parameter information and specify the scheme name in order for translation call to succeed.

Because the EPCglobal TDT standard is powerful and highly extensible, the Oracle Database RFID standard metadata is a close relative of the TDT specification. Thus, the Identity Code package is extensible: You can create your own categories and tag structures using generic metadata. To create a category of identity codes, use the DBMS_MGD_ID_UTIL.create_category function.

For example, suppose you want to create a category called MGD_SAMPLE_CATEGORY, which has two types of tags, a CONTRACTOR_TAG and an EMPLOYEE_TAG. This category and its two metadata schemes might be used within a company that must grant different access privileges to people who are full time employees from those who are contractors, and thus require that their security software be able to identify quickly between the two badge types at an RFID reader. This script creates a category named MGD_SAMPLE_CATEGORY, with a 1.0 category version, having an agency name as Oracle, with a URI as http://www.oracle.com/mgd/sample. See Adding Two Metadata Schemes to a Newly Created Category for an example.

Next, create an CONTRACTOR_TAG metadata scheme such as:

<?xml version="1.0" encoding="UTF-8"?>
<TagDataTranslation version="0.04" date="2005-04-18T16:05:00Z" 
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema" 
                    xmlns="oracle.mgd.idcode">
 <scheme name="CONTRACTOR_TAG" optionKey="1" xmlns="">
  <level type="URI" prefixMatch="mycompany.contractor.">
   <option optionKey="1" pattern="mycompany.contractor.([0-9]*).([0-9]*)" 
           grammar="''mycompany.contractor.'' contractorID ''.'' divisionID">
    <field seq="1" characterSet="[0-9]*" name="contractorID"/>
    <field seq="2" characterSet="[0-9]*" name="divisionID"/>
   </option>
  </level>
  <level type="BINARY" prefixMatch="11">
   <option optionKey="1" pattern="11([01]{7})([01]{6})" 
           grammar="''11'' contractorID divisionID ">
    <field seq="1" characterSet="[01]*" name="contractorID"/>
    <field seq="2" characterSet="[01]*" name="divisionID"/>
   </option>
  </level>
 </scheme>
</TagDataTranslation>

The CONTRACTOR_TAG scheme contains two encoding levels, or ways in which the tag can be represented. The first level is URI and the second level is BINARY. The URI representation starts with the prefix "mycompany.contractor." and is then followed by two numeric fields separated by a period. The names of the two fields are contractorID and divisionID. The pattern field in the option tag defines the parsing structure of the tag URI representation, and the grammar field defines how to reconstruct the URI representation. The BINARY representation can be understood in a similar fashion. This representation starts with the prefix "01" and is then followed by the same two fields, contractorID and divisionID, this time, in their respective binary formats. Given this XML metadata structure, contractor tags can now be decoded from their URI and BINARY representations and the resulting fields can be re-encoded into one of these representations.

The EMPLOYEE_TAG scheme is defined in a similar fashion and is shown as follows.

<?xml version="1.0" encoding="UTF-8"?>
<TagDataTranslation version="0.04" date="2005-04-18T16:05:00Z" 
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema" 
                    xmlns="oracle.mgd.idcode">
 <scheme name="EMPLOYEE_TAG" optionKey="1" xmlns="">
  <level type="URI" prefixMatch="mycompany.employee.">
   <option optionKey="1" pattern="mycompany.employee.([0-9]*).([0-9]*)" 
           grammar="''mycompany.employee.'' employeeID ''.'' divisionID">
    <field seq="1" characterSet="[0-9]*" name="employeeID"/>
    <field seq="2" characterSet="[0-9]*" name="divisionID"/>
   </option>
  </level>
  <level type="BINARY" prefixMatch="01">
   <option optionKey="1" pattern="01([01]{7})([01]{6})" 
           grammar="''01'' employeeID divisionID ">
    <field seq="1" characterSet="[01]*" name="employeeID"/>
    <field seq="2" characterSet="[01]*" name="divisionID"/>
   </option>
  </level>
 </scheme>
</TagDataTranslation>;

To add these schemes to the category ID previously created, use the DBMS_MGD_ID_UTIL.add_scheme function.

This script creates the MGD_SAMPLE_CATEGORY category, adds a contractor scheme and an employee scheme to the MGD_SAMPLE_CATEGORY category, validates the MGD_SAMPLE_CATEGORY scheme, tests the tag translation of the contractor scheme and the employee scheme, then removes the contractor scheme, tests the tag translation of the contractor scheme and this returns the expected exception for the removed contractor scheme, tests the tag translation of the employee scheme and this returns the expected values, then removes the MGD_SAMPLE_CATEGORY category:

--contents of add_scheme2.sql
SET LINESIZE 160
CALL DBMS_MGD_ID_UTL.set_proxy('example.com', '80');
---------------------------------------------------------------------
---CREATE CATEGORY, ADD_SCHEME, REMOVE_SCHEME, REMOVE_CATEGORY-------
---------------------------------------------------------------------
DECLARE
  amt          NUMBER;
  buf          VARCHAR2(32767);
  pos          NUMBER;
  tdt_xml      CLOB;
  validate_tdtxml VARCHAR2(1042);
  category_id  VARCHAR2(256);
BEGIN
  -- remove the testing category if it exists
  DBMS_MGD_ID_UTL.remove_category('MGD_SAMPLE_CATEGORY', '1.0');
  -- create the testing category 'MGD_SAMPLE_CATEGORY', version 1.0
  category_id := DBMS_MGD_ID_UTL.CREATE_CATEGORY('MGD_SAMPLE_CATEGORY', '1.0', 'Oracle', 
'http://www.oracle.com/mgd/sample');
  -- add contractor scheme to the category
  DBMS_LOB.CREATETEMPORARY(tdt_xml, true);
  DBMS_LOB.OPEN(tdt_xml, DBMS_LOB.LOB_READWRITE);
 
  buf := '<?xml version="1.0" encoding="UTF-8"?>
<TagDataTranslation version="0.04" date="2005-04-18T16:05:00Z" 
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema" 
                    xmlns="oracle.mgd.idcode">
 <scheme name="CONTRACTOR_TAG" optionKey="1" xmlns="">
  <level type="URI" prefixMatch="mycompany.contractor.">
   <option optionKey="1" pattern="mycompany.contractor.([0-9]*).([0-9]*)" 
           grammar="''mycompany.contractor.'' contractorID ''.'' divisionID">
    <field seq="1" characterSet="[0-9]*" name="contractorID"/>
    <field seq="2" characterSet="[0-9]*" name="divisionID"/>
   </option>
  </level>
  <level type="BINARY" prefixMatch="11">
   <option optionKey="1" pattern="11([01]{7})([01]{6})" 
           grammar="''11'' contractorID divisionID ">
    <field seq="1" characterSet="[01]*" name="contractorID"/>
    <field seq="2" characterSet="[01]*" name="divisionID"/>
   </option>
  </level>
 </scheme>
</TagDataTranslation>';

  amt := length(buf);
  pos := 1;
  DBMS_LOB.WRITE(tdt_xml, amt, pos, buf);
  DBMS_LOB.CLOSE(tdt_xml);

  DBMS_MGD_ID_UTL.ADD_SCHEME(category_id, tdt_xml);

  -- add employee scheme to the category
  DBMS_LOB.CREATETEMPORARY(tdt_xml, true);
  DBMS_LOB.OPEN(tdt_xml, DBMS_LOB.LOB_READWRITE);
 
  buf := '<?xml version="1.0" encoding="UTF-8"?>
<TagDataTranslation version="0.04" date="2005-04-18T16:05:00Z" 
                    xmlns:xsi="http://www.w3.org/2001/XMLSchema" 
                    xmlns="oracle.mgd.idcode">
 <scheme name="EMPLOYEE_TAG" optionKey="1" xmlns="">
  <level type="URI" prefixMatch="mycompany.employee.">
   <option optionKey="1" pattern="mycompany.employee.([0-9]*).([0-9]*)" 
           grammar="''mycompany.employee.'' employeeID ''.'' divisionID">
    <field seq="1" characterSet="[0-9]*" name="employeeID"/>
    <field seq="2" characterSet="[0-9]*" name="divisionID"/>
   </option>
  </level>
  <level type="BINARY" prefixMatch="01">
   <option optionKey="1" pattern="01([01]{7})([01]{6})" 
           grammar="''01'' employeeID divisionID ">
    <field seq="1" characterSet="[01]*" name="employeeID"/>
    <field seq="2" characterSet="[01]*" name="divisionID"/>
   </option>
  </level>
 </scheme>
</TagDataTranslation>';

  amt := length(buf);
  pos := 1;
  DBMS_LOB.WRITE(tdt_xml, amt, pos, buf);
  DBMS_LOB.CLOSE(tdt_xml);
  DBMS_MGD_ID_UTL.ADD_SCHEME(category_id, tdt_xml);

  -- validate the scheme
  dbms_output.put_line('Validate the MGD_SAMPLE_CATEGORY Scheme');
  validate_tdtxml := DBMS_MGD_ID_UTL.validate_scheme(tdt_xml);
  dbms_output.put_line(validate_tdtxml);
  dbms_output.put_line('Length of scheme xml is: '||DBMS_LOB.GETLENGTH(tdt_xml));

  -- test tag translation of contractor scheme
  dbms_output.put_line(
    mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                     'mycompany.contractor.123.45', 
                     NULL, 'BINARY'));

  dbms_output.put_line(
    mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                     '111111011101101',
                     NULL, 'URI'));

  -- test tag translation of employee scheme
  dbms_output.put_line(
    mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                     'mycompany.employee.123.45', 
                     NULL, 'BINARY'));

  dbms_output.put_line(
    mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                     '011111011101101',
                     NULL, 'URI'));

  DBMS_MGD_ID_UTL.REMOVE_SCHEME(category_id, 'CONTRACTOR_TAG');

  -- Test tag translation of contractor scheme. Doesn't work any more.
  BEGIN
    dbms_output.put_line(
      mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                       'mycompany.contractor.123.45', 
                       NULL, 'BINARY'));

    dbms_output.put_line(
      mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                       '111111011101101',
                       NULL, 'URI'));
  EXCEPTION 
    WHEN others THEN
      dbms_output.put_line('Contractor tag translation failed: '||SQLERRM);
  END;

  -- Test tag translation of employee scheme. Still works.
  BEGIN
    dbms_output.put_line(
      mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                       'mycompany.employee.123.45', 
                       NULL, 'BINARY'));
    dbms_output.put_line(
      mgd_id.translate('MGD_SAMPLE_CATEGORY', NULL, 
                       '011111011101101',
                       NULL, 'URI'));
  EXCEPTION 
    WHEN others THEN
      dbms_output.put_line('Employee tag translation failed: '||SQLERRM);
  END;

  -- remove the testing category, which also removes all the associated schemes
  DBMS_MGD_ID_UTL.remove_category('MGD_SAMPLE_CATEGORY', '1.0');
END;
/
SHOW ERRORS;
call DBMS_MGD_ID_UTL.remove_proxy();

@add_scheme3.sql
.
.
.
Validate the MGD_SAMPLE_CATEGORY Scheme
EMPLOYEE_TAG;URI,BINARY;divisionID,employeeID
Length of scheme xml is: 933
111111011101101
mycompany.contractor.123.45
011111011101101
mycompany.employee.123.45
Contractor tag translation failed: ORA-55203: Tag data translation level not found
ORA-06512: at "MGDSYS.DBMS_MGD_ID_UTL", line 54
ORA-06512: at "MGDSYS.MGD_ID", line 242
ORA-29532: Java call terminated by uncaught Java
exception: oracle.mgd.idcode.exceptions.TDTLevelNotFound: Matching level not
found for any configured scheme
011111011101101
mycompany.employee.123.45
.
.
.