D4を更に理解しよう

ORDA: Object Relational Data Access

Table, field, and relation names are mapped to object property names. Make sure that such names comply with general object naming rules, as explained in the object naming conventions section.
A datastore only references tables with a single primary key. The following tables are not referenced:
Tables without a primary key
Tables with composite primary keys.
BLOB type attributes are not managed in the datastore. BLOB type attributes are returned as Null in entities and cannot be assigned.

$mydatastore:=OB Copy(ds) 
 ARRAY TEXT($prop;0)
 OB GET PROPERTY NAMES(ds;$prop)

こりゃハードル高いというか、時間がかかるな。。