AlterQuery  defaults (children 2)
 ExpressionList (children 1)
  AlterCommand ADD_COLUMN (children 1)
   ColumnDeclaration n (children 1)
    DataType Nested (children 1)
     ExpressionList (children 2)
      NameTypePair a (children 1)
       DataType UInt64
      NameTypePair b (children 1)
       DataType String
 Identifier defaults
