The second example illustrates receiving a list of disjoint Nodes and also illustrates that an array of results can be received.
Example 2: Get PersonType.LastName, AnimalType.Name where a person has a child or (a pet is of type cat and has a feeding schedule).
The NodeTypeDescription parameters used in the example are described in Table B.6.
Table B.6 – Example 2 NodeTypeDescription
|
Type Definition Node |
Include Subtypes |
QueryDataDescription |
Relative Path |
Attribute |
Index Range |
|
PersonType |
FALSE |
“.12:LastName” |
Value |
N/A |
|
AnimalType |
TRUE |
“.12:Name” |
Value |
N/A |
The corresponding ContentFilter is illustrated in Figure B.6.
Figure B.6 – Example 2 filter logic tree
Table B.7 describes the elements, operators and operands used in the example. It is worth noting that a CatType is a subtype of AnimalType.
Table B.7 – Example 2 ContentFilter
|
Element[] |
Operator |
Operand[0] |
Operand[1] |
Operand[2] |
Operand[3] |
|
0 |
Or |
ElementOperand=1 |
ElementOperand = 2 |
|
|
|
1 |
RelatedTo |
AttributeOperand = NodeId: PersonType, BrowsePath “.”, Attribute: NodeId |
AttributeOperand = NodeId: PersonType, BrowsePath “.”, Attribute: NodeId |
AttributeOperand = NodeId: HasChild, BrowsePath “.”, Attribute: NodeId |
LiteralOperand = ‘1’ |
|
2 |
RelatedTo |
AttributeOperand = NodeId: CatType, BrowsePath “.”, Attribute: NodeId |
AttributeOperand = NodeId: FeedingScheduleType, BrowsePath “.”, Attribute: NodeId |
AttributeOperand = NodeId: HasSchedule, BrowsePath “.”, Attribute: NodeId |
LiteralOperand = ‘1’ |
The results from this query would contain the QueryDataSets shown in Table B.8.
Table B.8 – Example 2 QueryDataSets
|
NodeId |
TypeDefinition NodeId |
RelativePath |
Value |
|
12:30 (Jfamily1) |
PersonType |
. 12:LastName |
Jones |
|
12:42 (HFamily1) |
PersonType |
. 12:LastName |
Hervey |
|
12:48 (HFamily2) |
PersonType |
. 12:LastName |
Hervey |
|
12:70 (Cat1) |
CatType |
. 12:Name |
Rosemary |
|
12:74 (Cat2) |
CatType |
. 12:Name |
Basil |
NOTE The relative path column and browse name (in parentheses in the NodeId column) are not in the QueryDataSet and are only shown here for clarity. The TypeDefinition NodeId would be a NodeId not the symbolic name that is included in the table.