correlated-subquery

This question already has an answer for SQL , and I was able to implement that solution in R using sqldf . However, I've been unable to find a way to implement it using data.table . The problem is to count the distinct values of one column within a rolling date range, e.g. (and quoting directly from the linked question) if the data looked like this: Date | email -------+---------------- 1/1/12 | test@test.com 1/1/12 | test1@test.com 1/1/12 | test2@test.com 1/2/12 | test1@test.com 1/2/12 | test2@test.com 1/3/12 | test@test.com 1/4/12 | test@test.com 1/5/12 | test@test.com 1/5/12 | test@test.com

I have the following table structure: Item ID | Name -------- 1 | Apple 2 | Pear 3 | Banana 4 | Plum 5 | Tomato Event ItemStart | ItemEnd | EventType | EventDate -------------------------------------------- 1 | 2 | Planted | 2014-01-01 1 | 3 | Picked | 2014-01-02 3 | 5 | Eaten | 2014-01-05 The two tables are linked only by the primary key of Item and the range of ItemStart and ItemEnd (inclusive) in Event. Events always refer to contiguous sequences of Items, but not all the Events for a given Item will have the same range. Events never occur on the same date for a given Item. The query I'd

I don't understand the behaviour in this case. In my understanding a query with an invalid sub-query should result in an error. But in this example it returns some rows. Test-Data: create table test_values ( tst_id number, tst_id2 number, tst_value varchar2( 10 ) ); create table test_lookup ( tst_id number, tst_value varchar2( 10 ) ); insert into test_values( tst_id, tst_id2, tst_value ) values ( 1, 2, 'a' ); insert into test_values( tst_id, tst_id2, tst_value ) values ( 1, 2, 'b' ); insert into test_values( tst_id, tst_id2, tst_value ) values ( 2, 2,'c' ); insert into test_values( tst_id, tst

I'm having this Mysql query, It works: SELECT nom ,prenom ,(SELECT GROUP_CONCAT(category_en) FROM (SELECT DISTINCT category_en FROM categories c WHERE id IN (SELECT DISTINCT category_id FROM m3allems_to_categories m2c WHERE m3allem_id = 37) ) cS ) categories ,(SELECT GROUP_CONCAT(area_en) FROM (SELECT DISTINCT area_en FROM areas c WHERE id IN (SELECT DISTINCT area_id FROM m3allems_to_areas m2a WHERE m3allem_id = 37) ) aSq ) areas FROM m3allems m WHERE m.id = 37 The result is: nom prenom categories areas Man Multi Carpentry,Paint,Walls Beirut,Baalbak,Saida It works correclty, but only when i

Is there a way to write with JPA 2 CriteriaBuilder the equivalent of the following query? select * from season s1 where end = ( select max(end) from season s2 where s1.contest_id=s2.contest_id ); In JPQL this query is: Select s1 from Season s1 where s1.end = ( select max(s2.end) from Season s2 where s1.contest=s2.contest ) This should work, with contest being either a basic Integer property, or a ManyToOne property pointing to another non-basic Entity. EntityManger em; //to be injected or constructed CriteriaBuilder cb = em.getCriteriaBuilder(); CriteriaQuery<Season> cq = cb.createQuery(Season