How to get the count of relations?

const products = await db.query.masterProducts.findMany({
  limit: pageSize,
  offset: page * pageSize,
  where: whereFilter
});

const products = await db.query.masterProducts.findMany({
  limit: pageSize,
  offset: page * pageSize,
  where: whereFilter
});

const products = await db.query.masterProducts.findMany({
  limit: pageSize,
  offset: page * pageSize,
  where: whereFilter
});

const products = await db.query.masterProducts.findMany({
  limit: pageSize,
  offset: page * pageSize,
  where: whereFilter
});

I have another table

inventoryItems

inventoryItems

inventoryItems

inventoryItems and there is a one-to-many relationship where one

masterProduct

masterProduct

masterProduct

masterProduct can have many

inventoryItems

inventoryItems

inventoryItems

inventoryItems and one

inventoryItem

inventoryItem

inventoryItem

inventoryItem is linked to one and only one

masterProduct

masterProduct

masterProduct

masterProduct on the

masterProductId

masterProductId

masterProductId

masterProductId field.

How can I include a count of

inventoryItems

inventoryItems

inventoryItems

inventoryItems in this query? I just want a

number

number

number

number of how many

inventoryItems

inventoryItems

inventoryItems

inventoryItems have the

masterProductId

masterProductId

masterProductId

masterProductId field matching the

id

id

id

id field for each row in the

masterProducts

masterProducts

masterProducts

masterProducts query