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| 1 : | parrello | 1.1 | <?xml version='1.0' standalone='yes'?> |
| 2 : | <Database> | ||
| 3 : | <Title>Attributes Database</Title> | ||
| 4 : | <Entities> | ||
| 5 : | <Entity name="AttributeGroup" keyType="name-string"> | ||
| 6 : | <Notes>A [i]group[/i] is a named set of attribute keys. An attribute key can belong to | ||
| 7 : | many groups or none at all.</Notes> | ||
| 8 : | </Entity> | ||
| 9 : | <Entity name="AttributeKey" keyType="name-string"> | ||
| 10 : | <Notes>An [i]attribute key[/i] describes named values attached to a particular type of object. | ||
| 11 : | Each instance of this entity contains the attribute's description and its name. An attribute | ||
| 12 : | key name must consist of letters, numbers, periods, underscores, and hyphens.</Notes> | ||
| 13 : | <Fields> | ||
| 14 : | <Field name="description" type="text"> | ||
| 15 : | <Notes>Text describing the attribute. This should explain what the attribute means and | ||
| 16 : | what kinds of values are appropriate.</Notes> | ||
| 17 : | </Field> | ||
| 18 : | <Field name="data-type" type="name-string"> | ||
| 19 : | <Notes>ERDB data type for the attribute. This serves as documentation only, but | ||
| 20 : | that may change at some future point.</Notes> | ||
| 21 : | </Field> | ||
| 22 : | </Fields> | ||
| 23 : | </Entity> | ||
| 24 : | parrello | 1.2 | <Entity name="TargetObject" keyType="string"> |
| 25 : | <Notes>An [i]object[/i] represents a keyed thing to which an attribute can be assigned. | ||
| 26 : | In order to improve performance, this table has no data in it. It is simply required by | ||
| 27 : | the semantics of the database.</Notes> | ||
| 28 : | parrello | 1.1 | </Entity> |
| 29 : | </Entities> | ||
| 30 : | <Relationships> | ||
| 31 : | <Relationship name="IsInGroup" from="AttributeKey" to="AttributeGroup" arity="MM"> | ||
| 32 : | <Notes>This relationship connects an attribute key to the groups of which it is a member.</Notes> | ||
| 33 : | </Relationship> | ||
| 34 : | parrello | 1.2 | <Relationship name="HasValueFor" from="AttributeKey" to="TargetObject" arity="MM"> |
| 35 : | <Notes>This relationship connects an attribute key to its objects. It contains the | ||
| 36 : | attribute values, and is therefore the primary data repository for the database.</Notes> | ||
| 37 : | <Fields> | ||
| 38 : | parrello | 1.4 | <Field name="value" type="text" indexed="1"> |
| 39 : | parrello | 1.2 | <Notes>This is the actual attribute value. Note that a single key/object pair may in fact |
| 40 : | have many values, and therefore many entries in this table.</Notes> | ||
| 41 : | </Field> | ||
| 42 : | </Fields> | ||
| 43 : | parrello | 1.1 | </Relationship> |
| 44 : | </Relationships> | ||
| 45 : | </Database> |
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