Using JPA, I have a list of entries from m开发者_如何学Goy database :
User(id, firstname, lastname, email)
That I get by doing:
List<User> users = User.find("lastname = ?", "smith");
And I'd like to update all in one request, by doing something like this :
"UPDATE USER SET email = null IN :list"
and then set the parameter "list" to users
Is it possible? if so, how?
Thanks for your help :)
Well, you could embed the query that you used to obtain list in the where clause of the update.
UPDATE User a SET a.email = null
WHERE user IN (SELECT b FROM User b WHERE lastName = :?)
By doing this you'd be doing the query to search the list and the update in single update query.
How do you like that? Do you think this could work?
-EDIT-
Since you want to use the original list of items instead of a list just retrieved from the database, you can still ensure you build the original list like this
UPDATE User a SET a.email = null
WHERE user IN (SELECT b FROM User b WHERE lastName IN(:originalList))
Then when you invoke it, you can do something like this:
Collection<String> originalList = Arrays.asList("Kenobi", "Skywalker", "Windu");
query.setParameter("originalList", originalList);
By this, you can still ensure the query will only contain items in your original list and not any possible new item from the database, provided that that last name is a candidate key in the database, otherwise I would recommend that you use the ID for the subquery instend of the last name.
if you have jpa+hibernate you can use entityManager.createQuery() for creating hql query like that:
String hql = "UPDATE Supplier SET name = :newName WHERE name IN :name";
entityManager.createQuery(hql);
精彩评论