Expand rows with generators

This how-to shows how to use generator helpers when nested values should reshape a relation.

Generators return GeneratorApplication values. Apply them through generate(...) so the relation keeps its input columns and appends the generated output aliases.

Explode array values

Use explode(...) when each array element should become a generated row.

from pub::incql import LazyFrame
from pub::incql.functions import col, explode
from models import Order

def order_lines(orders: LazyFrame[Order]) -> LazyFrame[Order]:
    return orders.generate(explode(col("line_items"), "line_item"))

Inline struct arrays

Use inline(...) when the generated rows should expose one output column per struct field.

from pub::incql import LazyFrame
from pub::incql.functions import array, inline, lit, named_struct
from models import Order

def fixed_items(orders: LazyFrame[Order]) -> LazyFrame[Order]:
    rows = array([
        named_struct(["sku", "quantity"], [lit("A"), lit(1)]),
        named_struct(["sku", "quantity"], [lit("B"), lit(2)]),
    ])
    return orders.generate(inline(rows, ["sku", "quantity"]))

For the full generator catalog and alias rules, see Generator and table-valued functions.