Intersection of two relations

Question

Say I have two relations that hold records in the same model, such as:

@companies1 = Company.where(...)
@companies2 = Company.where(...)

Ho

Answer 1

Use sql keyword INTERSECT.

params1 = [1,2,4]
params2 = [1,3,4]
query = "
SELECT companies.* FROM companies
WHERE id in (?,?,?)
INTERSECT
SELECT companies.* FROM companies
WHERE id in (?,?,?)
"
Company.find_by_sql([query, *params1, *params2])

it will be faster than previous solution.