Values.ColumnSchemaSourceMetadata for a column.
type nonrec t = {columnName : ColumnName.t;The name of a column.
*)columnTypes : ColumnTypeList.t;The data type of column.
*)}val to_value :
t ->
[> `Structure of
(string
* [> `List of [> `Enum of string ] list | `String of ColumnName.t ])
list ]