ORMLITE是否支持SQL EXISTS？

Question

我想查询表如下

select * from client c 
    where EXISTS (select * from visit v where c._id = v.client_id) 

我能做到这一点与ORMLITE？

Answer 1

是的，你可以。 Where.exists()已支持我的ORMLite一段时间。下面是[微薄]文档：

http://ormlite.com/docs/exists

你会做类似以下内容：

QueryBuilder<Visit, Integer> visitQb = visitDao.queryBuilder(); 
visitQb.where().eq(Visit.CLIENT_ID_FIELD, client.getId()); 
QueryBuilder<Client, Integer> clientQb = clientDao.queryBuilder(); 
clientQb.where().exists(visitQb); 
List<Client> results = clientQb.query();