I'm using QueryDLS.
But I got some problems.
My Database server is MariaDB.
select s.* , a.user_id
from schedule s
left outer join(
select sch_idx, group_concat(user_id SEPARATOR ',') as user_id
from attendee a
group by sch_idx
) a
on s.idx = a.sch_idx;
and this is my code( Ofcoursly, It' is wrong)
public void selectJoin(){
JPAQueryFactory query = new JPAQueryFactory(em);
QSchedule qSchedule = QSchedule.schedule;
QAttendee qAttendee = QAttendee.attendee;
query.selectFrom(qSchedule)
.leftJoin(
query.select(
qAttendee.schIdx,
qAttendee.userId
).from(qAttendee)
.groupBy(qAttendee.schIdx)
).on(qSchedule.idx.eq(qAttendee.schIdx))
.fetch();
}
How can I insert subquery in the join like my sql sample?
And I Have to resolve Group_concat in QueryDSL
If I can not resolve my truoble by QueryDSL, Let me know what is best solutions.
please, I need your help!
Related
The datastore is postgres. Can someone help in translating this to an Objection.js statement? It's easy to do this with two roundtrips, but ideally this would happen in one.
INSERT INTO reports (
id,
created_by,
desc,
dataset
)
SELECT
'8971e660-7777-4d64-8cc3-171512063fff',
123,
'clone!',
r.dataset,
FROM reports r
WHERE r.id = '7771e660-9d7d-4d64-8cc3-17151206354f';
All of the documentation for Cosmos DB and it looks like it only supports the JOINkeyword, which seems to be a sort of INNER JOIN.
I have the following query:
SELECT * FROM
(
SELECT
DISTINCT(c.id),
c.OtherCollection,
FROM c
JOIN s IN c.OtherCollection
)
AS c order by c.id
This works fine and returns the data of documents that have OtherCollection populated. But It obviously does not return any documents that do not have it populated.
The reason for the join is that sometimes I execute the following query (queries are built up from user input)
SELECT * FROM
(
SELECT
DISTINCT(c.id),
c.OtherCollection,
FROM c
JOIN s IN c.OtherCollection
WHERE s.PropertyName = 'SomeValue'
)
AS c order by c.id
The question is how can I have a sort of LEFT JOIN operator in this scenario?
CosmosDB JOIN operation is limited to the scope of a single document. What possible is you can join parent object with child objects under same document.
It is totally different from SQL Join query which supports across two/many tables.
You can simulate LEFT JOIN with the EXISTS sentence.
Eg:
SELECT VALUE c
FROM c
WHERE (
(c.OtherCollection = null) OR EXISTS (--Like a "Left Join"
SELECT null
FROM s IN c.OtherCollection
WHERE s.PropertyName = 'SomeValue'
)
)
--AND/OR Some other c Node conditions
order by c.id
Is it possible to use .QueryMultiple (or some other method) in Dapper, and use the results of each former query to be used in the where clause of the next query, without having to do each query individually, get the id, and then .Query again, get the id and so on.
For example,
string sqlString = #"select tableA_id from tableA where tableA_lastname = #lastname;
select tableB_id from tableB WHERE tableB_id = tableA_id";
db.QueryMultiple.(sqlString, new {lastname = "smith"});
Is something like this possible with Dapper or do I need a view or stored procedure to accomplish this? I can use multiple joins for one SQL statement, but in my real query there are 7 joins, and I didn't think I should return 7 objects.
Right now I'm just using object.
You can store every previous query in table parameter and then first perform select from the parameter and query for next, for example:
DECLARE #TableA AS Table(
tableA_id INT
-- ... all other columns you need..
)
INSERT #TableA
SELECT tableA_id
FROM tableA
WHERE tableA_lastname = #lastname
SELECT *
FROM #TableA
SELECT tableB_id
FROM tableB
JOIN tableA ON tableB_id = tableA_id
Can I do something like this on JPQL?
SELECT NEW com.MyDTO(p.a, p.b, q.c, q.d)
FROM
(SELECT r.* FROM MyDTO1 r ) p
LEFT OUTER JOIN
(SELECT s.* FROM MyDTO2 s ) q
ON p.x = q.y
or similar?
(Above query has mixed with native and JPQL, so don't misunderstand)
I'm having a problem with this part I think.
FROM
(SELECT r.* FROM MyDTO1 r ) p
When I'm trying to execute I'm getting this error.
Exception Description: Syntax error parsing the query [.....], unexpected token [(]
Thank you!
No, you can't. Quote from the documentation:
Note that HQL subqueries can occur only in the select or where
clauses.
Yes you can!
You have to use native queries. Here is an example:
emf = Persistence.createEntityManagerFactory("TEST")
EntityManager em = emf.createEntityManager();
String queryString = "SELECT ID FROM ( SELECT * FROM ADDRESS WHERE ID < 0)";
Query query = em.createNativeQuery(queryString);
List<BigDecimal> result = query.getResultList();
I want to perform a simple join on two tables (BusinessUnit and UserBusinessUnit), so I can get a list of all BusinessUnits allocated to a given user.
The first attempt works, but there's no override of Select which allows me to restrict the columns returned (I get all columns from both tables):
var db = new KensDB();
SqlQuery query = db.Select
.From<BusinessUnit>()
.InnerJoin<UserBusinessUnit>( BusinessUnitTable.IdColumn, UserBusinessUnitTable.BusinessUnitIdColumn )
.Where( BusinessUnitTable.RecordStatusColumn ).IsEqualTo( 1 )
.And( UserBusinessUnitTable.UserIdColumn ).IsEqualTo( userId );
The second attept allows the column name restriction, but the generated sql contains pluralised table names (?)
SqlQuery query = new Select( new string[] { BusinessUnitTable.IdColumn, BusinessUnitTable.NameColumn } )
.From<BusinessUnit>()
.InnerJoin<UserBusinessUnit>( BusinessUnitTable.IdColumn, UserBusinessUnitTable.BusinessUnitIdColumn )
.Where( BusinessUnitTable.RecordStatusColumn ).IsEqualTo( 1 )
.And( UserBusinessUnitTable.UserIdColumn ).IsEqualTo( userId );
Produces...
SELECT [BusinessUnits].[Id], [BusinessUnits].[Name]
FROM [BusinessUnits]
INNER JOIN [UserBusinessUnits]
ON [BusinessUnits].[Id] = [UserBusinessUnits].[BusinessUnitId]
WHERE [BusinessUnits].[RecordStatus] = #0
AND [UserBusinessUnits].[UserId] = #1
So, two questions:
- How do I restrict the columns returned in method 1?
- Why does method 2 pluralise the column names in the generated SQL (and can I get round this?)
I'm using 3.0.0.3...
So far my experience with 3.0.0.3 suggests that this is not possible yet with the query tool, although it is with version 2.
I think the preferred method (so far) with version 3 is to use a linq query with something like:
var busUnits = from b in BusinessUnit.All()
join u in UserBusinessUnit.All() on b.Id equals u.BusinessUnitId
select b;
I ran into the pluralized table names myself, but it was because I'd only re-run one template after making schema changes.
Once I re-ran all the templates, the plural table names went away.
Try re-running all 4 templates and see if that solves it for you.