Data model is one special kind of models (the other kinds are ThingModels and AppModels). Therefore it has all the properties of Models (Lifecycle of models, Model Attributes, Unique and Constraints).
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| System Attribute Name | Description |
|---|---|
| Value | The value of the attribute is stored in "Value". This is specified by user at time of create query |
| Known | Applicable to ThingFacet/AppFacet - this is the value that is set within the Action. Known can not be set using Create / Update TQL Query by the user. |
| Version | Version number of the attribute. This number is automatically incremented each time the value changes. |
| Timestamp | Unix epoch time at the time (in millisecond) of the attribute creation. For example: Timestamp value1457663102004 is same as Fri, 11 Mar 2016 02:25:02 GMT |
| Datetime | Formatted data time value of the attribute creation. For example:2016-03-10 18:25:02.004 |
| QName | Fully qualified name of the attribute. <NamSpace>.<Domain>.<ModelName>.<AttributeName>. For example SimpleModel.MyModels.VendorInfo.vendorName given that VendorInfo is defined within Namespace - SimpleModel, with Domain as MyModels and DataModel Name as VendorInfo |
| FName | Given name of the attribute name. |
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| Code Block | ||||||
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<Def Name="PostalAddress"> <String Name="Street"/> <String Name="City"/> <String Name="Zipcode"/> </Def> <DataModel Name="VendorInfo"> <Sid name="VendorSysId"/> <String name="vendorName"/> <String name="vendorTitle"/> <PostalAddress name="VendorAddress"/> <String Name="DeviceTypes" Cardinality="0..m"/> </DataModel> |
Create Data Model with Array Attribute
| Code Block | ||||||
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<Query>
<Create>
<VendorInfo>
<vendorName>Phidget</vendorName>
<vendorTitle>Sensor Provider</vendorTitle>
<vendorAddress>
<Street>123 TQL Way</Street>
<City>Sunnyvale</City>
<Zipcode>91234</Zipcode>
</vendorAddress>
<DeviceTypes>Sensors</DeviceTypes>
<DeviceTypes>Actuators</DeviceTypes>
</VendorInfo>
</Create>
</Query> |
Unique Constraints on DataModel
Unique Constraint defined Data Identity definition using list of attributes. Once defined the TQLEngine ensures that a combination of attribute values are unique across all objects.
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| Code Block | ||||||
|---|---|---|---|---|---|---|
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<Create Status="Failure">
<VendorInfo>
<VendorSysId>chag3vw7tcet7dvg2athubjwl2gvth73</VendorSysId>
<VendorName Status="Failure!UpdateConflict:Create:Record exists:integrity constraint violation: unique constraint or index violation; SYS_PK_10098 table: TR;" Value="Phidget"/>
<VendorTitle Status="Failure!UpdateConflict:Create:Record exists:integrity constraint violation: unique constraint or index violation; SYS_PK_10098 table: TR;" Value="Sensor Provider"/>
<VendorAddress>
<Street Status="Failure!UpdateConflict:Create:Record exists:integrity constraint violation: unique constraint or index violation; SYS_PK_10098 table: TR;" Value="123 TQL Way"/>
<City Status="Failure!UpdateConflict:Create:Record exists:integrity constraint violation: unique constraint or index violation; SYS_PK_10098 table: TR;" Value="Sunnyvale"/>
<Zipcode Status="Failure!UpdateConflict:Create:Record exists:integrity constraint violation: unique constraint or index violation; SYS_PK_10098 table: TR;" Value="91234"/>
</VendorAddress>
</VendorInfo>
</Create> |
DataModel by picking Attributes from other defined DataModel
We famously call such DataModel as "Cherry Picked DataModel". Attributes are Cherry picked from some other defined model.
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| Code Block | ||||||
|---|---|---|---|---|---|---|
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<Find Status="Success">
<Result>
<SensorVendorInfo>
<SensorVendorSysId>chag3vw7tcet7dvg2athubjwl2gvth73</SensorVendorSysId>
<SensorVendorName>Phidget</SensorVendorName>
</SensorVendorInfo>
</Result>
</Find> |
DataModel by picking Attributes from other defined DataModel + newly defined Attributes
DataModel can contain both cherry picked attributes as well as new attributes. Here SensorVendorInfo contains SensorTypes as new attribute of type string.
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| Code Block | ||||||
|---|---|---|---|---|---|---|
| ||||||
<Find Status="Success">
<Result>
<VendorInfo>
<VendorSysId>KNTR2FJXAAAAUAABA5OUP375</VendorSysId>
<VendorName>Phidget</VendorName>
</VendorInfo>
</Result>
</Find> |
Selective Cherry picking using Constraint
In some cases we may want to selective pick attributes. For example, We only want Vendors with Sensor DeviceType. This can be achieved using Constraint.
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