CODEWITHSUNDEEP
javahibernatehql
xander27
xander27

Reputation: 3124

HQL nested subqueries

I have such domain: Country has cities, city has offices, offices has services. I need to find all countries with offices which provide specified service id. My current version is:

SELECT c FROM Country c 
WHERE EXISTS(
             SELECT ct FROM c.cities ct 
             WHERE EXISTS(
                          SELECT o FROM ct.offices o 
                          WHERE EXISTS(
                                       SELECT s.id FROM o.services s 
                                       WHERE s.id = :id
                                      )
                         ) 
            )

So, I'm new to HQL. What is best way to this? Is my version Ok? I was thinking about SELECT DISTINCT with LEFT JOIN too.

Upvotes: 3

Views: 384

Answers (1)

Glenn Lane
Glenn Lane

Reputation: 4030

I don't think there is anything wrong with your query, but this might be more readable.

SELECT c FROM Country
WHERE EXISTS (
    SELECT s.id FROM
    c.cities ct
    JOIN ct.offices o
    JOIN o.services s
    WHERE s.id = :id
)

Upvotes: 2

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