intersect

TypeScript only

left.intersect(right)

Problem

Given two relations with the same heading, find tuples that appear in both.

Example: I want to find products that are both bestsellers AND on sale.

Description

The set intersection of two relations. The result contains only those tuples that exist in both left and right.

The result’s heading is identical with that of the inputs’.

Requirements

The headings of the two relations must be identical.

Example

const myPurchases = Bmg([
  { product_id: 10, quantity: 2 },
  { product_id: 10, quantity: 4 },
  { product_id: 20, quantity: 1 },
])

const yourPurchases = Bmg([
  { product_id: 10, quantity: 2 },
  { product_id: 10, quantity: 4 },
  { product_id: 20, quantity: 5 },
  { product_id: 30, quantity: 1 },
])

myPurchases.intersect(yourPurchases).toArray()

// =>
// [{ product_id: 10, quantity: 2 },
//  { product_id: 10, quantity: 4 }]

Relationship to other set operations

Operator	Result
union	Tuples in either relation
intersect	Tuples in both relations
minus	Tuples in left but not right