$savedorderby

Functionality

Definition

The $savedorderby endpoint allows you to save the sort order defined by the $orderby parameter when creating an entity set. This ensures that the sort order is preserved even if the entity set is removed from the server's cache.

Syntax

To save the order by when creating an entity set, use the following syntax:

GET /rest/{{dataClass}}?$filter="{{filterExpression}}"&$savedfilter="{{filterExpression}}"&$orderby="{{orderbyExpression}}"&$savedorderby="{{orderbyExpression}}"&$method=entityset

Detailed Behavior

Saving and Retrieving Sort Order

When you create an entity set with $savedorderby, the sort order is saved and can be retrieved later. If the entity set is removed and then recreated, the new entity set will have the same sort order applied.

tip

By using $savedorderby, the sort order defined when creating the entity set is preserved. When you retrieve the entity set, you must pass $savedorderby along with your call to ensure the sort order is applied.

Combining with Other Parameters

The $savedorderby parameter can be combined with other parameters to maintain consistent sorting criteria for entity sets:

• $filter: Combine with $savedfilter to save and apply both filtering and sorting criteria.

• $top/$limit and $skip: Navigate through the sorted entity set while maintaining the saved sorting order.

• $expand: Include related data in the sorted results, ensuring the sorting criteria are consistently applied.

• $attributes: Specify which attributes to include in the sorted results, preserving the sorting order.

• $method=entityset: Create an entity set with a saved sort order, allowing for consistent retrieval of sorted data.

• $compute: Apply computations on the sorted dataset while ensuring the sorting criteria are maintained.

• $entityset: Use the saved sorting order when accessing entity sets to maintain consistency in data presentation.

• $queryplan: Analyze the query plan for the saved sorting order to understand and optimize its performance.

• $querypath: Trace the execution path of the query with the saved sorting order to identify optimization opportunities.

• $lock: Ensure data integrity by applying consistent sorting criteria when locking and unlocking entities.

Use Cases

Creating an Entity Set with $savedorderby

Request:

GET /rest/People?$filter="lastName!=''"&$savedfilter="lastName!=''"&$orderby="salary"&$savedorderby="salary"&$method=entityset

Response:

{
    "__ENTITYSET": "/rest/People/$entityset/FC0EB10EBC4A485DAF52267E30708724",
    "__DATACLASS": "People",
    "__entityModel": "People",
    "__GlobalStamp": 0,
    "__COUNT": 19,
    "__FIRST": 0,
    "__ENTITIES": [
        {
            "__KEY": "1",
            "__TIMESTAMP": "2024-05-09T16:50:24.070Z",
            "__STAMP": 1,
            "ID": 1,
            "firstName": "John",
            "lastName": "Smith",
            "salary": 50000
        },
        {
            "__KEY": "2",
            "__TIMESTAMP": "2024-05-09T16:50:24.070Z",
            "__STAMP": 2,
            "ID": 2,
            "firstName": "Jane",
            "lastName": "Doe",
            "salary": 60000
        }
    ]
}

Accessing the Entity Set with $savedorderby

Request:

GET /rest/People/$entityset/FC0EB10EBC4A485DAF52267E30708724?$savedfilter="lastName!=''"&$savedorderby="salary"

Response:

{
    "__DATACLASS": "People",
    "__entityModel": "People",
    "__GlobalStamp": 0,
    "__COUNT": 19,
    "__FIRST": 0,
    "__ENTITIES": [
        {
            "__KEY": "1",
            "__TIMESTAMP": "2024-05-09T16:50:24.070Z",
            "__STAMP": 1,
            "ID": 1,
            "firstName": "John",
            "lastName": "Smith",
            "salary": 50000
        },
        {
            "__KEY": "2",
            "__TIMESTAMP": "2024-05-09T16:50:24.070Z",
            "__STAMP": 2,
            "ID": 2,
            "firstName": "Jane",
            "lastName": "Doe",
            "salary": 60000
        }
    ]
}

Best Practices

• Consistent Use of $savedfilter and $savedorderby: Always use $savedfilter and $savedorderby together to ensure that both the filter and sort order are preserved.

• Regular Monitoring: Monitor the status of entity sets in the server's cache to avoid unexpected removals.

• Optimal Timeout Settings: Adjust the timeout settings based on your application's requirements to balance performance and data availability.