We are using below linq:
var query1 = from m in _appContext.TabEmployee
group m by m.AspUserID into g
select g.OrderByDescending(p => p.Id).First();
var query2 = from q in query1
join c in _appContext.TabCompany on q.AspUserID equals c.AspUserID
select c;
var result = query2.ToList().AsQueryable();
But we are getting below error while running above code:
'The LINQ expression 'DbSet<TabEmployee>() could not be translated. Either rewrite the query in a form that can be translated, or switch to client evaluation explicitly by inserting a call to 'AsEnumerable', 'AsAsyncEnumerable', 'ToList', or 'ToListAsync'. See https://go.microsoft.com/fwlink/?linkid=2101038 for more information.'
But if we change query 1 to below, we do not get any errors:
var query1 = from m in _appContext.TabEmployee
Here, we have removed the sql part which groups by AspUserID and takes first record in every group by ordering by Id column. We need this logic. What change do we need to make to fix above issue?
Thank you.
Related
How to write this query in JPA?
select sol.ID_UNICA, sol.version
from uexdfr01.SOLUTION sol
join
(select solution4_.ID_UNICA, max(solution4_.version) as maxVersion
from uexdfr01.ORDER order3_
inner join uexdfr01.SOLUTION solution4_ on order3_.ID_SOLUTION=solution4_.ID_SOLUTION
where solution4_.ID_UNICA in (130,139,143,129,126,128,141,121,124,131)group by solution4_.ID_UNICA) as groupedtt
on sol.ID_UNICA = groupedtt.ID_UNICA
AND sol.version = groupedtt.maxVersion*
If you are not sure about db relationships use createNativeQuery and pass your query inside parenthesis.
Query selectRecords = getEntityManager().createNativeQuery(sqlQuery.toString());
Returned values are type of Objects so make sure to assign them in List as following way..
List<Object[]> data= selectRecords.getResultList();
I'm trying make a query with HQL that will stay with the same order as given list of IDs. I know it's possible with SQL but I can't find any way to do it with HQL (and I cannot do it with native SQL because I got many joins)
Example
fingerIds = [3,1,10,4]
SELECT p FROM People p
JOIN FETCH p.fingers f
WHERE f.id IN :fingerIds
DB: PostgreSQL 10.4
Hibernate: 4.3.11.Final
Eg. Given list of IDs: [3,1,10,4]
Actual result's order: [1,3,4,10]
Expected result's order: [3,1,10,4]
You can obtain the order by adding to your query the keyword FIELD, in your example:
SELECT p FROM People p
JOIN FETCH p.fingers f
WHERE f.id IN :fingerIds
ORDER BY FIELD(f.ID,3,1,10,4)
Ofc you can replace the numbers with your variable :fingerIds
You can find more about that command here.
Returns the index (position) of str in the str1, str2, str3, ... list. Returns 0 if str is not found.
I am using mysql 5.5 with openjpa 2.3.0.
I have entities with namedQueries (generated in netbeans - I would like to be able to use this), for example:
#NamedQuery(name = "User.findAll", query = "SELECT u FROM User u")
#NamedQuery(name = "User.findByGender", query = "SELECT u FROM User u WHERE u.gender = :gender")
I am creating restfull aplication with paged results. I would like to return for every paged result the Content-Range header as 1-20/250 where 20 is pagesize, 250 total count.
I tried to create a query
entityManager.createNativeQuery("SELECT count(1) FROM (" + namedQuery.toString() + ") as foo;");
where I could dynamicaly insert any named query and return the count without returning the result list -> it should be faster.
When I execute this, exception occurs
SQL state 42S22: Unknown column 'u' in 'field list'
Executing the query itself in entitymanager is ok.
Can I use the entity manager or criteria builder to create a query for counting results without returning the result list (and without writing for every namedQuery a count duplicate)? thank you for helping.
You are mixing JPQL with native queries. JPQL says SELECT u FROM entity u, SQL would be SELECT * FROM entity u or SELECT col1,col2,col3 FROM entity u
You could write a JPQL named query counting the stuff, e.g. SELECT COUNT(u) FROM entity u. A getSingleResult() would then return an Object[], whose first element contains the count.
Not nice but working. Why do You have to query for the number anyway? Pagination means next = lastindex+pagesize. if next < lastindex+pagesize, the end is reached.
I originally thought this error was specific to Entity Framework. But now think it has something to do with BreezeJS's EFContextProvider.
I have a linq query that works fine in both Entity Framework and Linq-to-sql:
var dc = new EFContextProvider<MyEntities>();
var query =
(from t1 in dc.Context.Table1
where (from t2 in dc.Context.Table2 select t2.TypeID).Distinct().Contains(t1.TypeID)
select t1);
On execution of this query, I get the error: Unable to create a constant value of type "Table2"
But, if I execute the query directly against Entity Framework:
var dc = new MyEntities();
var query =
(from t1 in dc.Table1
where (from t2 in dc.Table2 select t2.TypeID).Contains(t1.TypeID)
select t1);
The query succeeds.
Any help would be appreciated :)
After reproducing and investigating the issue, we found that the error is happening in EF and we are unable to fix it. However, we found that this behavior is due to the "dotted" path within the query
dc.Context.Table2
and the workaround is to simply avoid such:
var dc = new EFContextProvider<MyEntities>();
var dc1 = dc_breeze.Context;
var query =
(from t1 in dc.Context.Table1
where (from t2 in dc1.Table2 select t2.TypeID).Distinct().Contains(t1.TypeID)
select t1);
I am trying to create an Entity SQL that is a union of two sub-queries.
(SELECT VALUE DISTINCT ROW(e.ColumnA, e.ColumnB, 1 AS Rank) FROM Context.Entity AS E WHERE ...)
UNION ALL
(SELECT VALUE DISTINCT ROW(e.ColumnA, e.ColumnB, 2 AS Rank) FROM Context.Entity AS E WHERE ...)
ORDER BY *??* LIMIT 50
I have tried:
ORDER BY Rank
and
ORDER BY e.Rank
but I keep getting:
System.Data.EntitySqlException: The query syntax is not valid. Near keyword 'ORDER'
Edit:
This is Entity Framework. In C#, the query is executed using:
var esql = "...";
ObjectParameter parameter0 = new ObjectParameter("p0", value1);
ObjectParameter parameter1 = new ObjectParameter("p1", value2);
ObjectQuery<DbDataRecord> query = context.CreateQuery<DbDataRecord>(esql, parameter0, parameter1);
var queryResults = query.Execute(MergeOption.NoTracking);
There is only a small portion of my application where I have to resort to using Entity SQL. Generally, the main use case is when I need to do: "WHERE Column LIKE 'A % value % with % multiple % wildcards'".
I do not think it is a problem with the Rank column. I do think it is how I am trying to apply an order by to two different esql statements joined by union all. Could someone suggest:
How to apply a ORDER BY to this kind of UNION/UNION ALL statment
How to order by the non-entity column expression.
Thanks.