{ ( column datatype [DEFAULT expr] [column_ref_constraint]
   [column_constraint [column_constraint]...] )
| table_or_view_constraint 
| table_ref_constraint
}  
[, { ( column datatype [DEFAULT expr] [column_ref_constraint]
      [column_constraint [column_constraint]...] )
   | table_or_view_constraint 
   | table_ref_constraint
   } 
]...
alter_column_properties

For information on the symbols and conventions of Backus-Naur Form (BNF) syntax, see Appendix A.