EXTEND(...)

All functions > ARRAY OF ROWS > EXTEND(...)

Adds computed feature fields to a base row or array of rows with field bindings

Syntax

EXTEND(
  base
  WITH feature AS field [, feature AS field ...]
  [ VIA field [, field ...] [ BIND TO feature [, feature ...] ] ]
)

Notes

Allows adding computed features as new fields to existing rows
BINDING clause maps base fields to feature inputs
Features are computed using the bound field values
Works with both single rows and arrays of rows
New field names must not conflict with existing fields

Related Functions

EXTEND()

Examples

Single base row

FeatureQL

DEFINE
    -- ** Setup the relational model **
    orders := ENTITY(),
    order_id := INPUT(BIGINT#orders),
    stores := ENTITY(),
    store_id := INPUT(BIGINT#stores),
    -- ** Declare external data sources **
    tables.orders := INLINE_COLUMNS(
        order_id BIGINT#orders BIND TO order_id,
        order_store_id BIGINT#stores
        FROM CSV(
            order_id,order_store_id
            10,20
            11,21
            12,22
            13,21
            14,22
            15,21
        )
    ),
    tables.stores := INLINE_COLUMNS(
        store_id BIGINT#stores BIND TO store_id,
        store_category VARCHAR,
        store_city VARCHAR
        FROM CSV(
            store_id,store_category,store_city
            20,PIZZA,BCN
            21,SUSHI,MAD
            22,BURGER,VAL
        )
    ),
    -- ** Define new features **
    order_store_id := tables.orders[order_store_id],
    order_store_id_details := EXTEND(
        ROW(order_store_id AS order_store_id)
        WITH tables.stores[store_category] AS store_category,
        tables.stores[store_city] AS store_city
        VIA order_store_id BIND TO store_id
    )
RETURN
    order_id,
    order_store_id,
    order_store_id_details
FOR
    order_id := BIND_VALUES(ARRAY(10, 12, 15))
;

Result

ORDER_ID BIGINT#ORDERS	ORDER_STORE_ID BIGINT#STORES	ORDER_STORE_ID_DETAILS ROW<order_store_id BIGINT#STORES, store_category VARCHAR, store_city VARCHAR>
10	20	{order_store_id: 20, store_category: PIZZA, store_city: BCN}
12	22	{order_store_id: 22, store_category: BURGER, store_city: VAL}
15	21	{order_store_id: 21, store_category: SUSHI, store_city: MAD}

Array of rows

FeatureQL

DEFINE
    -- ** Setup the relational model **
    customers := ENTITY(),
    orders := ENTITY(),
    customer_id := INPUT(BIGINT#customers), -- We just need our primary key CUSTOMER_ID as inputs
    order_id := INPUT(BIGINT#orders),
    -- ** Simulating a customer table. Notice the list of order_ids. **
    customer_source := INLINE_COLUMNS(
        customer_id BIGINT#customers BIND TO customer_id,
        order_ids ARRAY(BIGINT#orders)
        FROM CSV(
            customer_id,order_ids
            1,"[10, 13]"
            2,"[11, 14, 15]"
            3,"[12, 99]"
        )
    ),
    order_ids := customer_source[order_ids],
    -- ** Simulating an order table. Notice there is no customer_id foreign key. **
    order_source := INLINE_COLUMNS(
        order_id BIGINT#orders BIND TO order_id,
        price DOUBLE
        FROM CSV(
            order_id,price
            10,12.51
            11,13.20
            12,15.06
            13,25.70
            14,30.26
            15,10.00
        )
    ),
    -- ** We need to add the price to each entry of the ORDER_IDS feature **
    order_ids_details := EXTEND(
        ZIP(order_ids AS order_id)
        WITH order_source[price] AS order_price
        VIA order_id BIND TO order_id
    )
RETURN
    customer_id,
    order_ids_details,
    revenue_per_customer := ARRAY_SUM(order_ids_details[order_price])
FOR
    customer_id := BIND_VALUES(ARRAY(1, 2, 3))
;

Result

CUSTOMER_ID BIGINT#CUSTOMERS	ORDER_IDS_DETAILS ARRAY<ROW<order_id BIGINT#ORDERS, order_price DOUBLE>>	REVENUE_PER_CUSTOMER DOUBLE
1	[{order_id: 10, order_price: 12.51}, {order_id: 13, order_price: 25.70}]	38.21
2	[{order_id: 11, order_price: 13.20}, {order_id: 14, order_price: 30.26}, {order_id: 15, order_price: 10.00}]	53.46
3	[{order_id: 12, order_price: 15.06}, {order_id: 99, order_price: NULL}]	15.06

Chained EXTEND

FeatureQL

DEFINE
    orders := ENTITY(),
    order_id := INPUT(BIGINT#orders),
    order_data := INLINE_COLUMNS(
        order_id BIGINT#orders BIND TO order_id,
        store_id BIGINT#stores
        FROM CSV(
            order_id,store_id
            10,20
            11,21
            12,22
        )
    ),
    stores := ENTITY(),
    store_id := INPUT(BIGINT#stores),
    store_data := INLINE_COLUMNS(
        store_id BIGINT#stores BIND TO store_id,
        category VARCHAR
        FROM CSV(
            store_id,category
            20,PIZZA
            21,SUSHI
            22,BURGER
        )
    ),
    order_rows := ZIP(ARRAY(10, 11, 12) AS order_id),
    orders_with_store := EXTEND(
        order_rows
        WITH order_data[store_id] AS store_id
        VIA order_id BIND TO order_id
    ),
    enriched := EXTEND(
        orders_with_store
        WITH store_data[category] AS category
        VIA store_id BIND TO store_id
    )
RETURN
    enriched
;

Result

ENRICHED ARRAY<ROW<order_id BIGINT, store_id BIGINT#STORES, category VARCHAR>>
[{order_id: 10, store_id: 20, category: PIZZA}, {order_id: 11, store_id: 21, category: SUSHI}, {order_id: 12, store_id: 22, category: BURGER}]

Last update at: 2026/10/13 08:32:21

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