Creates a temporary DEC DATATRIEVE port with the name you specify
       and readies the port for WRITE access. DEC DATATRIEVE does not
       enter a definition of the port in the Oracle CDD/Repository data
       dictionary.

       Format

         DECLARE PORT  port-name USING

               level-number-1 field-definition-1.

               [level-number-2 field-definition-2.]
                      .          .
                      .          .
                      .          .
               [level-number-n field-definition-n.]
          ;