ECDbMap (ECDb DB Mapping) Schema

Specify a database index for an ECClass.

Properties

Applies to: EntityClass, RelationshipClass

Properties

Applies to: EntityClass, RelationshipClass

Properties

Creates a foreign key for this navigation property.

Applies to: NavigationProperty

Properties

Flags a relationship to be an automatic view, based on navigation properties on the constraint classes.

Applies to: RelationshipClass

Causes a schema to only be imported by a specific ECDb version or higher.

Applies to: Schema

The ECDbRuntimeVersion value specifies which ECDb version is required to import this schema. This gets compared to the highest ECDb profile version known to the current ECDb runtime, which may be higher than the currently open file profile version. Older versions of ECDb will refuse to import schemas that have this CA (import will be rejected). If the schema is already in a file, older versions of ECDb are good to use it, if usage of things should be restricted, apply UseRequiresVersion instead.

Example usage:

<?xml version="1.0" encoding="utf-8" ?>
<ECSchema schemaName="Schema1" alias="s1" version="1.0.1" xmlns="http://www.bentley.com/schemas/Bentley.ECXML.3.2">
    <ECSchemaReference name="ECDbMap" version="02.00.02" alias="ecdbmap"/>
    <ECCustomAttributes>
        <ImportRequiresVersion xmlns="ECDbMap.02.00.02">
            <ECDbRuntimeVersion>4.0.0.5</ECDbRuntimeVersion>
        </ImportRequiresVersion>
    </ECCustomAttributes>
    <ECEntityClass typeName="Foo" >
        <ECProperty propertyName="Length" typeName="double" />
    </ECEntityClass>
</ECSchema>

Properties

Maps subclasses and their children to a joined table. Can only be applied to classes in a hierarchy using MapStrategy TablePerHierarchy.

Applies to: EntityClass

Applies to: RelationshipClass

Properties

Applies to: PrimitiveProperty

Properties

Flags a class as a view based on ECSQL.

Applies to: EntityClass

Allows defining an abstract entity class which is not backed by actual data but rather by an ECSql query which is executed to obtain instances of the class. Please see ECSqlReference for details on how to use views.

A view must return an ECInstanceId and ECClassId.

Example of a schema using a view:

<ECSchema schemaName="TestSchema" alias="ts" version="1.0.0" xmlns="http://www.bentley.com/schemas/Bentley.ECXML.3.2">
    <ECSchemaReference name='ECDbMap' version='02.00.03' alias='ecdbmap' />
    <ECEntityClass typeName="JsonObject">
        <ECProperty propertyName="json" typeName="string" extendedTypeName="Json" />
    </ECEntityClass>
    <ECEntityClass typeName="Pipe" modifier="Abstract">
        <ECCustomAttributes>
            <QueryView xmlns="ECDbMap.02.00.04">
                <Query>
                    SELECT
                        jo.ECInstanceId,
                        ec_classid('TestSchema', 'Pipe') as [ECClassId]
                        CAST(json_extract(jo.json, '$.diameter') AS INTEGER) [Diameter],
                        CAST(json_extract(jo.json, '$.length') AS INTEGER) [Length],
                        json_extract(jo.json, '$.material') [Material]
                    FROM ts.JsonObject jo
                    WHERE json_extract(jo.json, '$.type') = 'pipe'
                </Query>
            </QueryView>
        </ECCustomAttributes>
        <ECProperty propertyName="Diameter" typeName="int" />
        <ECProperty propertyName="Length"  typeName="int"/>
        <ECProperty propertyName="Material" typeName="string" />
    </ECEntityClass>
</ECSchema>

JsonObject could be filled with this data:

{"type": "pipe", "diameter": 10, "length": 100, "material": "steel"}
{"type": "pipe", "diameter": 15, "length": 200, "material": "copper"}
{"type": "pipe", "diameter": 20, "length": 150, "material": "plastic"}
{"type": "cable", "diameter": 5, "length": 500, "material": "copper","type": "coaxial"}
{"type": "cable", "diameter": 2, "length": 1000, "material": "fiber optic","type": "single-mode"}
{"type": "cable", "diameter": 3, "length": 750, "material": "aluminum","type": "twisted pair"}

Running this query:

SELECT Length, Diameter, Material FROM ts.Pipe

Will return this result:

Length   |Diameter |Material
----------------------------------------
100      |10       |steel
200      |15       |copper
150      |20       |plastic

Properties

Applies to: Schema

Properties

Allows to share columns amongst ECProperties. Can only be applied to MapStrategy TablePerHierarchy

Applies to: EntityClass, RelationshipClass

Properties

Causes ECDb to refuse to query a class which has this CA or a CA that has this CA if conditions are not met.

Applies to: AnyClass

Can be applied to a class which makes queries which use that class require a minimum ECDb or ECSql version. When applied to a custom attribute class, that custom attribute carries the information along to all classes to which it is being applied. (Nesting is also possible).

Applying this to anything other than a relationship, entity or custom attribute class has no effect.

ECSqlVersion specifies the minimum ECSql version which is maintained independend of the ECDb profile version and allows a second mechanism for tracking changes (the sql version is usually incremented more frequently than profile version)

ECSql queries which violate the restrictions set by this CA will fail to prepare and write a message to the ECDb issue reporter.

The use of this CA does not limit which ECDb versions can import the schemas. To restrict import apply the ImportRequiresVersion CA to the schema.

Example usage:

<?xml version="1.0" encoding="utf-8" ?>
<ECSchema schemaName="Schema1" alias="s1" version="1.0.1" xmlns="http://www.bentley.com/schemas/Bentley.ECXML.3.2">
    <ECSchemaReference name="ECDbMap" version="02.00.02" alias="ecdbmap"/>
    <ECCustomAttributeClass typeName="Bar" modifier="Sealed" appliesTo="EntityClass">
        <ECCustomAttributes>
            <UseRequiresVersion xmlns="ECDbMap.02.00.02">
                <ECDbRuntimeVersion>4.0.0.4</ECDbRuntimeVersion>
            </UseRequiresVersion>
        </ECCustomAttributes>
    </ECCustomAttributeClass>
    <ECEntityClass typeName="Foo" >
        <ECCustomAttributes>
            <Bar></Bar>
        </ECCustomAttributes>
        <ECProperty propertyName="Length" typeName="double" />
    </ECEntityClass>
</ECSchema>

Example for directly applying this to an entity class, restricting its ECSql version:

<ECEntityClass typeName="Foo" >
    <ECCustomAttributes>
        <UseRequiresVersion xmlns="ECDbMap.02.00.02">
            <ECSqlVersion>1.0.0.0</ECSqlVersion>
        </UseRequiresVersion>
    </ECCustomAttributes>
    <ECProperty propertyName="Length" typeName="double" />
</ECEntityClass>

<ECEntityClass typeName="Bar">
    <BaseClass>Foo</BaseClass>
</ECEntityClass>

Class Bar in the example above will also be affected by the restriction since it derives from Foo.

Properties