Drawing Relations:
- 1:M relations are drawn as directed linksbetween nodes that represent parent and child entity types on a DSD. An arrow head OR arrow tail denotes the child end.
- Either half of the link may be dashed or solid. Dashed link ends indicate mincard = 0 (optional). Solid links indicate mincard = 1 (mandatory). Source code from GEN does not yet enforce this distinction.
- bde2sch creates one foreign (f)key field in the child table for each arrow head (or tail) that points into (or out of) the child table type, respectively.
- Chgen creates distinct fkey names for two links connecting the same table pair (AAid1 and AAid2 in table BB above).