Repository findIn confusion - spring-data

Question

My database has an Exchanges class which contains a list of CurrencyPairs.
Is it possible to use to use a Repository method to directly obtain a CurrencyPair which matches on name within a given Exchange? I'm thinking of something like
CurrencyPairDbo findByExchangeNameAndCurrencyPairIn(...)
but I can't see quite how to tie it all together. Or do I need to write a custom query for this? And does this need to be in the ExchangeRepository or the CurrencyPairRespository?
#Entity()
#Table(name = "Exchanges")
public class ExchangeDbo {
#Id #GeneratedValue
#Getter private Long id;
#Getter private String exchangeName;
#OneToMany(mappedBy = "exchange",
cascade = CascadeType.ALL,
orphanRemoval = true,
fetch = FetchType.EAGER)
#BatchSize(size=100)
#Getter private List<CurrencyPairDbo> listCurrencyPair = new ArrayList<>();
...
}
#Entity()
public class CurrencyPairDbo {
#Id #GeneratedValue
#Getter private Long id;
#Column(unique=true)
private String currencyPair;
#ManyToOne(fetch=FetchType.EAGER)
#Getter private ExchangeDbo exchange;
...
}
Edit:
I'm thinking it's not Find...In that I want at all. I think that something like:
List<CurrencyPairDbo> x = exchangeRepository.findByExchangeNameLowercaseAndListCurrencyPairCurrencyPair(exchangeName.toLowerCase(), currencyPair);
might work, except that in returns an Exchange object and a:
org.springframework.core.convert.ConverterNotFoundException: No converter found capable of converting from type [biz.ianw.coindatabase.database.ExchangeDbo] to type [biz.ianw.coindatabase.database.CurrencyPairDbo]

Answer 1

This, in the currency pair repository, seems to do the job.
I added a lower case field for matching purposes and an index for efficiency.
CurrencyPairDbo findByExchangeExchangeNameLowercaseAndCurrencyPairNameLowercase( String exchangeName, String currencyPair );