Subitems: records inside records

Some records only make sense inside another one — the line items on an order, the serial numbers on a line item, the checklist items on a task. Subitems let you build those rows directly inside the parent record instead of creating them separately and linking them up afterwards. This article covers turning a table into subitems, the editable grid you get on the parent, nesting several levels, and what happens when you delete. Subitems vs. a plain relation Both connect two tables, but they mean different things. A plain Relation points at a record that exists on its own and gets reused — a customer, a part in your catalogue, a venue. You pick an existing one. Subitems mean ownership: the child belongs to exactly one parent and is created inside it. You add them, you don't pick them. Delete the parent and they go too. If you find yourself creating a record in one table just so you can link it from another, that relationship almost certainly wants to be subitems. Turn a table into subitems Do it from the parent — the way you'd describe it out loud (“an order has line items”). • Open the parent table and choose Edit fields. • In the Subitems panel, pick the child table. • Press Make subitems of …. RowFold adds the link on the child table pointing back at the parent (or reuses one that's already there). You never have to build the relation in reverse yourself. Already have the relation on the child table? Open that table's field editor and press Make subitems on the relation row instead — nothing is recreated and no links are lost. The grid on the parent record Open any parent record and the subitems appear as a grid below its fields, with an Add… button. Rows are editable in place — click a cell, type, tab onward. Computed columns ride along read-only, so a per-line lookup or rollup is visible while you work. The link back to the parent isn't shown as a column: it's always this record, so showing it would just be noise. A relation column inside the grid (a line item's part number, say) gets a picker that searches the target table — and if what you need isn't there yet, type the name and choose Create to make it and link it without leaving the row. Nesting several levels Subitems nest. If serial numbers are subitems of line items, and line items are subitems of orders, then each line item row in the order gets an expander (▸). Open it and that line item's serial numbers appear, with their own Add button. Levels load only when you expand them, so a long order stays fast. Nesting is capped at four levels deep — past that, open the row itself (↗) to keep going. Totals from subitems A Rollup on the parent summarises its subitems. An order total is a Rollup over Order Line Items, through the link back to the order, summing the amount field. Because the rollup follows the same link the grid does, the number tracks whatever you type into the rows. Deleting and restoring Deleting a parent sends its subitems to the Trash with it, all the way down — an order takes its line items, and their serial numbers. Restoring the parent from the Trash brings back the ones that went down with it. A subitem you had already deleted separately, before the parent, stays deleted — restoring a parent won't quietly resurrect things you meant to get rid of. Letting AI find the hierarchy When you describe a schema in Build with AI, it now marks the parent/child relationships itself — ask for orders with line items and serial numbers and you get the nesting, while shared things like a parts catalogue stay ordinary relations. The preview labels them inside … so you can see the shape before anything is created. For a workspace you've already built, open Schema and press Suggest hierarchy. It reviews the relations you have, proposes the ones that look like ownership with a reason for each, and applies only the ones you tick. Tips • Declare subitems from the parent table — it matches how you'd say it, and RowFold sorts out which side the link lives on. • Name the child table in the plural (“Order Line Items”): the Add button and section header are built from it. • Put an Order Total rollup on the parent so the number updates as you type into the grid. • Use the ↗ on a row to open that subitem as a full record when you need fields the grid doesn't show. Good to know • Subitems are for one-parent ownership. If a record could sensibly belong to two parents, keep it a plain relation. • Undoing subitems keeps the relation field and every link — only the ownership behaviour stops. Nothing is deleted. • Picking a value in a grid relation cell replaces what was there rather than adding to it. For multi-link relations, open the row with ↗. • Build with AI only designs new tables, so it won't retrofit hierarchy onto tables you already have — use Suggest hierarchy on the Schema page for those. • Permanently deleting a parent from the Trash doesn't purge its subitems; they stay in the Trash as orphans until you empty it. Who can do what • Only workspace Admins can make a table subitems or undo it — it's a schema change, checked again on the server. • The grid follows the child table's own permissions: no create permission means no Add button, no delete permission means no row delete, and fields you can't write render read-only. • A child table you can't view is left out of the parent record entirely. • Deleting a parent removes its subitems regardless of your permissions on the child table — ownership wins, because leaving orphans hidden under a deleted parent would be worse.