col-definition =

  --> <column-name> --+
      +---------------+
      +---> column-type ---+--------------------------+-+--+
      |                    +->DEFAULT   value-expr    | |  |
      |                    +->column-identity --------+ |  |
      +---> COMPUTED BY value-expr ---------------------+  |
      +-------------------------<--------------------------+
      +-+--------------------+----------------+
        +-> col-constraint --+                |
      +--------------------------<------------+
      ++------------------------+-----+-----------------------+->
       +-> comment-is-clause  --+     +-> sql-and-dtr-clause -+

    The definition for a column in the table. SQL gives you two ways
    to specify column definitions:

    o  By directly specifying a data type to associate with a column
       name

    o  By naming a domain that indirectly specifies a data type to
       associate with a column name

    Either way also allows options of specifying column constraints
    and formatting clauses.