Using the Criteria API, I can generate a query that creates a JOIN with an extra condition on the JOIN
var criteria = Session.CreateCriteria<Product>()
.SetReadOnly(true)
.SetMaxResults(1)
.CreateAlias("ProductCategory", "U", JoinType.LeftOuterJoin, Expression.Eq("U.SubType", "Premium"))
.AddOrder(Order.Desc("U.Sequence"));
This generates a JOIN similar to this:
SELECT * FROM dbo.Product w
LEFT JOIN dbo.ProductCategory u
ON u.DefaultProductId = w.Id AND u.SubType = 'Premium'
How do I do the same thing with the QueryOver syntax?
Off the top of my head I think it's like:
ProductCategory category = null;
var result = Session.QueryOver<Product>()
.JoinAlias(x => x.Categories, () => category, JoinType.LeftOuterJoin)
.Where(() => category.SubType == "Premium")
.OrderBy(() => category.Sequence).Desc
.Take(1)
.List();
Edit: Included OrderBy, and gave it a test. Works.
Using the Blog > Posts type example, the generated SQL looks like:
SELECT this_.Id as Id1_1_,
this_.Title as Title1_1_,
post1_.BlogId as BlogId3_,
post1_.Id as Id3_,
post1_.Id as Id3_0_,
post1_.Title as Title3_0_,
post1_.Content as Content3_0_,
post1_.DatePosted as DatePosted3_0_,
post1_.BlogId as BlogId3_0_
FROM [Blog] this_
left outer join [Post] post1_
on this_.Id = post1_.BlogId
WHERE post1_.DatePosted > '2011-11-22T19:43:11.00' /* #p0 */
ORDER BY post1_.DatePosted desc
.JoinAlias has an overload with a withClause
var result = Session.QueryOver<Product>()
.Left.JoinAlias(x => x.Categories, () => category, c => c.SubType == "Premium")
.OrderBy(() => category.Sequence).Desc
.Take(1)
.List();
Related
Hi I have this sql and have to translate into NHibernate QueryOver
SELECT S.Number, S.Description, S.BrandDescription, subquery.vendornumber, subquery.vendorname
FROM Stocks.Stock S left join
(select vendorNumber, VendorName, POLID, LastTransactionDate from
(
SELECT top 4 v.Number vendorNumber, v.Name VendorName, PLL.Id POLID, max(por.TransactionDate) as LastTransactionDate,
ROW_NUMBER() OVER(PARTITION BY v.Number ORDER BY max(por.TransactionDate) DESC) AS rk
FROM Purchasing.PurchaseOrderLineItem PLL
inner join Purchasing.PurchaseOrder po on PLL.PurchaseOrderId = po.Id
inner join Purchasing.PurchaseOrderVendor POV on po.Id = POV.PurchaseOrderId
inner join Purchasing.Vendor V on pov.VendorId = v.Id
left outer join Purchasing.PurchaseOrderReceipt POR on PLL.Id = por.PurchaseOrderLineItemId
group by v.Number, v.Name,PLL.Id
order by LastTransactionDate desc
) subquery
where subquery.rk = 1) B on PL.Id = b.POLID
Or just to explain it simply see its simplified version
Select * from master m
outer apply (select top 4 * From Details d where m.Id = d.Id order by someColumns desc)o
I think we cannot use subquery as derived table in nhibernate. If you have suggestions, please share.
Thanks
I was keep working on this and found that it could be very difficult if want to do totally with QueryOver. I want to show how I did this.
First I took all the vendors with StockID to join with StockQuery later.
var stockVendors =
Session.QueryOver<Vendor>(() => V)
.Left.JoinQueryOver(p => V.Stock, () => sstk)
.Where(sstk.Number !=null)
.OrderBy(Projections.Max(() => V.TransactionDate)).Desc()
.ThenBy(() => sstk.Number).Asc()
.ThenBy(() => sv.Number).Asc()
.SelectList(
lst =>
lst.SelectGroup(() => V.Name).WithAlias(() => svhModal.VendorName)
.SelectGroup(() => V.Number).WithAlias(() => svhModal.VendorNumber)
.SelectGroup(() => sstk.Number).WithAlias(() => svhModal.StockNumber)
.Select(Projections.Max(() => V.TransactionDate)).WithAlias(() => svhModal.LastTransactionDate)
)
.TransformUsing(Transformers.AliasToBean()).List();
Then select Stock only
var stockDetail = Session.QueryOver<Stock>(() => stk)
.Where(soneCriteria)
.SelectList(list => list
.Select(() => stk.Id).WithAlias(() => sdrModal.Id)
.Select(() => stk.Number).WithAlias(() => sdrModal.Number)
.TransformUsing(Transformers.AliasToBean<StockDetailReportModal>())
.List<StockDetailReportModal>();
IList<StockVendor> vlst2 = null;
IList<StockDetail> newStock = new List<StockDetail>();
Here starts two loops to fill List object with each stock and its 5 top vendors from vendors list. Loop from Stockdetail result from query and inside loop from vendor result filtered to outer loop stockid, get first 5 vendors only in loop, when done just return the result to report. Its working fine.
foreach (StockDetail ostk in stockDetail)
{
stkid = ostk.Number;
vlst2 = (from v in stockVendors where v.StockNumber == stkid orderby v.LastTransactionDate descending select v).ToList<StockVendor>();
vndrcnt = 0;
stok = new StockDetail
{
Id = ostk.Id,
Number = ostk.Number,
//// other fields too here
};
if (vlst2.Count() == 0)
{
newStock.Add(stok);
}
foreach (StockVendor vn in vlst2)
{
if (vndrcnt == 0)
{
stok.VendorName = vn.VendorName;
stok.VendorNumber = vn.VendorNumber;
// other fields here...
newStock.Add(stok);
}
else
{
newStock.Add(new StockDetail
{
Id = ostk.Id,
Number = ostk.Number,
VendorName = vn.VendorName,
VendorNumber = vn.VendorNumber,
// adding vendor information in stock record.
});
}
vndrcnt++;
if (vndrcnt >= 4)
break;
}
This solved my problem and achieved this after investigating many days. You may find better approach, so please share.
I need help converting this sql query into QueryOver Nhibernate criteria.
select distinct * from event e where e.name like '%req%'
or e.Id in (select r.eventId from requirement r where r.name like '%req%')
or e.Id in (select r.eventId from requirement r where r.id
in (select s.requirementId from solution s where s.name like '%sol%'))
var queryOver = session.QueryOver<Event>()
.Where(x => x.Name.IsInsensitiveLike("%"+searchTerms[1]+"%"))
.OrderBy(x => x.CreatedOn).Asc;
So far I have the main query but couldn't find enough reference material on how to add the subqueries. Haven't been successful using joinQueryOver.
Event has one-to-many rel with requirement and requirement has one-to-many rel with solution.
Requirement reqAlias = null;
Solution solAlias = null;
var subQuery = QueryOver.Of<Event>()
.JoinAlias(x => x.Requirements, () => reqAlias)
.Where(x => x.Name.IsInsensitiveLike(searchTerms[2]))
.JoinAlias(() => reqAlias.Solutions, () => solAlias)
.Where(x => x.Name.IsInsensitiveLike(searchTerms[3]))
.Select(Projections.Group<Event>(x => x.Id));
var events = session.QueryOver<Event>()
.Where(x => x.Name.IsInsensitiveLike(searchTerms[1]))
.WithSubquery.WhereProperty(x => x.Id).In(subQuery)
.List().ToList();
still not working.
When you use IsInsensitiveLike NHibernate appends the % after parsing, and uses lower to do a lower case comparison. In your code, you are appending the % yourself, which results in,
select distinct * from event e where e.name like %lower('%req%')%
which in turn, doesn't work.
Also, you have 3 subqueries, no a big one, so you need to restructure your code to account for that:
select r.eventId from requirement r where r.name like '%req%'
to
var firstQuery = QueryOver.Of<Requirement>()
.Where(r => r.Name.IsInsensitiveLike(searchTerms[2]))
.Select(r => r.EventId);
then,
select s.requirementId from solution s where s.name like '%sol%'
to
var solutionQuery = QueryOver.Of<Solution>()
.Where(s => s.Name.IsInsensitiveLike(searchTerms[3]));
then,
select r.eventId from requirement r where r.id
in (select s.requirementId from solution s where s.name like '%sol%')
to
var requirementQuery = QueryOver.Of<Requirement>()
.WithSubquery
.WhereProperty(r => r.Id).In(solutionQuery)
.Select(r => r.EventId);
Then you need to construct the main query using Restrictions.Or to include the 3 queries.
I've got 2 entities, linked many-to-many. (Product & User)
I want to restrict Products by Users:
User userAlias = null;
query.JoinAlias(product => product.Users, () => userAlias)
.Where(() => userAlias.Id == currentUser.Id);
It's generated SQL code:
SELECT this_.Id as y0_
FROM [Product] this_
inner join UserToProduct users5_
on this_.Id = users5_.Product_id
inner join [User] useralias3_
on users5_.User_id = useralias3_.Id
....
In "Where" i use only user_id and i don't need second join.
How I can write the query(by QueryOver) with a single SQL join ?
This may help? I have a similar setup with UsersRoles
Role roleAlias = null;
var roles = _session.QueryOver<UsersRole>().JoinAlias(x => x.Role, () => roleAlias, JoinType.LeftOuterJoin).Where(
x => x.User.UserId == userId).List();
produces the following:
SELECT this_.UsersRolesId as UsersRol1_32_1_,
this_.UserId as UserId32_1_,
this_.RoleId as RoleId32_1_,
rolealias1_.RoleId as RoleId27_0_,
rolealias1_.RoleName as RoleName27_0_,
rolealias1_.Active as Active27_0_,
rolealias1_.DateCreated as DateCrea4_27_0_,
rolealias1_.LastUpdated as LastUpda5_27_0_,
rolealias1_.RoleSettingsId as RoleSett6_27_0_
FROM UsersRoles this_
left outer join Roles rolealias1_
on this_.RoleId = rolealias1_.RoleId
WHERE this_.UserId = 'a7eec4eb-21cc-4185-8847-a035010e779f' /* #p0 */
I got a rather tough query to convert from SQL to LINQ-to-Entities.
Here's my SQL code:
select c_id
from db.c
inner join db.i on c_id = i_c
inner join db.l on c_id = l_c
group by c_id
having count(distinct i_attributeX) > count(distinct l_attributeY)
I seem to have problems with the distinct in linq. Any suggestions?
Cheers
How's this:
var result = db.c
.Where(c =>
c.i.Select(i => i.attributeX).Distinct().Count() >
c.l.Select(l => l.attributeY).Distinct().Count()
)
.Select(c => c.id);
or alternatively
var result = db.c
.Where(c =>
c.i.GroupBy(i => i.attributeX).Count() >
c.l.GroupBy(l => l.attributeY).Count()
)
.Select(c => c.id);
I have a HQL query:
select max(l.Num) from SomeTable l group by l.Type, l.Iteration
How can I translate/convert it to QueryOver?
Following one:
var grouped = session.QueryOver<SomeTable>()
.SelectList(l => l
.SelectGroup(x => x.Type)
.SelectGroup(x => x.Iteration)
.SelectMax(x => x.Num));
will generate SQL:
SELECT
MAX(l.Num),
l.Type,
l.Iteration
FROM
SomeTable l
GROUP BY
l.Type,
l.Iteration
which is not what I expect – I don’t want to have Type and Iteration in Select.
I'm using that query as subquery for select z from c where z IN (subquery).
try with this statement, I've used Aliases and UnderlyingCriteria
SomeTable someTb = null;
var grouped = session.QueryOver<SomeTable>(() => someTb)
.SelectList(l => l.SelectMax(() => someTb.lnum))
.UnderlyingCriteria.SetProjection(
Projections.Group(() => someTb.Type)
,Projections.Group(() => someTb.Iteration))
.List();
I hope it's helpful.