DTL transform¶

This is a transform that lets you apply Data Transformation Language transformations on the entities stream produced by the data source.

Properties¶

Property	Type	Description	Default	Req
`rules`	Object	The named rules of the DTL transform. The `default` named rule is required and is the rule that will be applied on the source entity. The other rules can be applied via the apply and apply-hops DTL functions.		Yes
`id_required`	Boolean	If `true` then the DTL transform will fail if the target entity’s `_id` property is either missing or is not a string. It will also do so if the arguments to “create” and “create-child” is not a dict or is missing the `_id` property or the `_id` property is of a non-string type. If the value is `false` then it will not fail in these situation. Instead the values will be ignored.	`true`

Example configuration¶

Pipe configuration that reads entities from the Northwind:Customers dataset and transforms them using the Data Transformation Language before writing them to the customer-with-orders dataset.

{
    "_id": "customer-with-orders",
    "name": "Customers with orders",
    "type": "pipe",
    "source": {
       "type": "dataset",
       "dataset": "Northwind:Customers"
    },
    "transform": {
        "type": "dtl",
        "rules": {
            "default": [
                ["copy", "_id"],
                ["add", "name", "_S.ContactName"],
                ["add", "orders", ["apply", "order", ["hops", {
                    "datasets": ["Northwind:Orders o"],
                    "where": [
                        ["eq", "_S._id", "o.CustomerID"]
                    ]
                }]]]
            ],
            "order": [
                ["add", "order_id", "_S.OrderID"],
                ["add", "order_date", "_S.OrderDate"]
            ]
        }
    }
}

Conditional transform

Emit children transform