I don’t think multiple dispatch solves this issue. Julia does have a strong type hierarchy and the proposed example with customers and accounts would be likewise hard to model. IMO only Rust like traits solves this issue elegantly.
What about cycles?
For example, "List all distinct customers from all accounts that are owned by customers who are members of some other subset of accounts".
I tried it with ChatGPT and it did produce a robust solution. This does not seem to be a limitation for strong type hierarchy after all:
```
# Define a struct for Customer struct Customer
id::Int
name::String
# Other customer-related fields
# Define a struct for Account
struct Account
id::Int
balance::Float64
type::String # e.g., "Savings", "Checking"
# Other account-related fields
# Define a struct to manage the many-to-many relationship
struct CustomerAccount
customer::Customer
account::Account
# Define a struct for the Bank which holds all information
struct Bank
customers::Dict{Int, Customer}
accounts::Dict{Int, Account}
customerAccounts::Vector{CustomerAccount}
```
Indeed. It produced a relational solution that emulates what you'd do with SQL tables.
This is approximately the schema shape we use in our product today.