Nodes of Key List
Nodes for key definitions of a specific table.
Operations on Main Tree View
Select the node of Key List to list existing keys on the content pane. Right-click on the node to
add a new key definition. Select the child node Key to edit the definition. You can delete the definition by right-clicking
or keying Del on the node.

Operations on content pane
Select node Key to show the definition of the key. Details are as follow.
* KEY Type and Seq.(Sequence)
KEY Type is a read-only property, as it's declared only when adding a new
key definition. Options of KEY Type are PK(Primary Key), SK(Secondary Key)
and FK(Foreign Key). Edit sequence(listing order) of the key definition
as needed(PK is compulsory sequenced on the top).
* Field List
A key can has one or multiple fields. Drag a node of Field onto Field List to add fields to the key definition. You can not add nor delete fields
from key definition which has relationship to other key definitions. Delete
relationship in order to add/delete key fields. Order of key fields can
be changed by dragging row of field on Field List.
* Relationship List
Relationship is defined by pairing two definitions of key. Drag node of Key onto Relationship List to add a new definition. When pairing keys , key types are compared and
the type of relationship is automatically chosen. Pairing rules for relationship
type are as follow.

- Pairing PK (or SK) and PK (or SK)
If number of key fields and data types are corresponding each other, SUBTYPE
relationship is given. If the key contains anothier key, FAMILY relationship
is given. In the example above, key of Table1 is a part of key of Table2.
Therefore, they are FAMILY and Table2 is a child. And Table4 is SUBTYPE
of Table3 as keys are equal and existance fo Table4 is conditional(condition
is mentioned in the definition of relationship).
- Pairing PK (or SK) and FK
If number of key fields and data types are corresponding each other, REFER
relationship is given. In the example above, as key of Table3 is PK and
key of Table2 is FK, they are in REFER relationship and Table2 is a refering
and Table3 is a refered.
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