I would like to convert to Hibernate query
sqlQuery= SELECT student_name, math + eng + lang from subject
Can anyone throw some light on how to get math + eng + lang?
Criteria criteria = hibernateSession
.createCriteria(subject.class);
ProjectionList projList = Projections.projectionList();
projList.add(Projections.property("student_name"));
Thanks in advance for your help
I am not sure there is an option in hibernate creteria query but alternatevely you can achive the same by having a method in calss Subject to calculate sum
class Subject {
....
public double getTotal() {
return math + eng + lang;
}
}
Another one option is to use Formula annotation. You can check this example
class Subject {
....
#Formula("math + eng + lang")
private double total
}
you can also use an SQL projection. It should be something like:
session.createCriteria(subject.class)
.createAlias("subject", "i")
.setProjection( Projections.projectionList()
.add( Projections.groupProperty("i.student_name") )
.add( Projections.groupProperty("i.math") )
.add( Projections.groupProperty("i.eng") )
.add( Projections.groupProperty("i.lang") )
.add( Projections.sqlProjection(
"math + eng + lang as total",
new String[] { "total" },
new Type[] { Hibernate.DOUBLE }
)
)
);
Related
How to select a specific column in a table?
This returns a row..
public static Model getData(String userId) {
return new Select().from(Model.class).where("userId=?", userId).executeSingle();
}
Replacing it as :
return new select("coloumnName").from(Model.class).where("userId=?", userId).executeSingle(); didnt work.
Provide a String[] to Select.
So you would do something like this:
new Select( new String[]{ "columnName" } )
.from( Model.class )
.where( "userId = ?", userId )
.executeSingle()
I have a database table. What I want is to get data using group by clause as I have used in below code.
Note that Decision is another table. now I want that all the decisions related to a specific Meeting Title should be shown in list.like
meetingtitle1=decision1,decison2,decison3
meetingtitle2=decision1,decison2
but below code returns only one decisiontitle.
public List<NewMeetings> GetAllMeetings()
{
var xyz = (from m in DB.MeetingAgenda
//join mp in Meeting on m.MeetingId equals mp.MeetingId
//where m.MeetingId == 2
group m by new { m.Meeting.MeetingTitle } into grp
select new NewMeetings
{
// meetingid = grp.Key.MeetingId,
meetingtitle = grp.Key.MeetingTitle,
decision = grp.Select(x => x.Decision.DecisionTitle).FirstOrDefault(),
total = grp.Count()
}).ToList();
List<NewMeetings> list = xyz.ToList();
return list;
}
public class NewMeetings
{
public int meetingid;
public string meetingtitle;
public string decision;
public int total;
}
Can somebody please tell me how to return a list of decisions to a specific Meetingtitle?
You are doing a FirstOrDefault on the list of decisions which obviously means you are only getting a single value. Instead you can join them all together into one longer string (separated by commas as you indicated in the question) by changing this line:
decision = grp.Select(x => x.Decision.DecisionTitle).FirstOrDefault(),
To this:
decision = string.Join(",", grp.Select(x => x.Decision.DecisionTitle)),
However, as the string.Join is not recognised by Linq to Entities, you need to do the string.Join after the data has been retrieved (i.e. after the ToList):
var xyz = (from m in DB.MeetingAgenda
group m by new { m.Meeting.MeetingTitle } into grp
select new
{
meetingtitle = grp.Key.MeetingTitle,
decisions = grp.Select(x => x.Decision.DecisionTitle),
total = grp.Count()
})
.ToList()
.Select(m => new NewMeetings
{
meetingtitle = m.meetingtitle,
decision = string.Join(",", m.decisions),
total = m.total
});
Hi i have a problem in QueryByilder in Doctrine. i wrote a Query that has 2 parameter and they affect in where statement. i want to ignore where statement if the related parameter was null. for example if $play = 3 and $theater = null the query must return all tickets with play 3 and whatever theater
this is my code:
public function getAllSearchedTickets($play,$teater){
return $this->getEntityManager()->createQuery('
select s from mtadminBundle:ReserveLocation s
join s.reserve a
join a.sance b
where a.acceptCode != 0
and b.play = :play
and b.teater = :teater')
->setParameters(array('play'=>$play,'teater'=>$teater))->getResult();
}
thank you.
You should use the QueryBuilder for this, to do it more efficiently, I'll show you how you do yours and then the same with the QueryBuilder as example:
Yours:
public function getAllSearchedTickets($play,$teater){
$query = 'select s from mtadminBundle:ReserveLocation s'.
'join s.reserve a'.
'join a.sance b'.
'where a.acceptCode != 0');
$paramArray = array();
if( $play ) {
$query .= ' and b.play = :play';
$paramArray['play'] = $play;
}
if( $teater ) {
$query .= ' and b.teater = :teater';
$paramArray['teater '] = $teater;
}
return $this->getEntityManager()->createQuery($query)
->setParameters($paramArray)->getResult();
}
QueryBuilder:
public function getAllSearchedTickets($play,$teater){
$queryBuilder = $this->getEntityManager()->createQueryBuilder();
$queryBuilder->select('s')
->from('mtadminBundle:ReserveLocation', 's')
->join('s.reserve', 'a')
->join('a.sance', 'b')
->where('a.acceptCode != 0');
if( $play ) {
$queryBuilder->andWhere('b.play = :play');
$queryBuilder->setParameter('play', $play);
}
if( $teater ) {
$queryBuilder->andWhere('b.teater = :teater');
$queryBuilder->setParameter('teater', $teater);
}
return $queryBuilder->getResult();
}
I have a Table(Send) with columns(Id, UserId,SendDate) and another table(Receive) with columns(Id,SendId,UserName).
I want show all records in SendTable with all RecieveUserName.
for example.
(Send)
1 1 2013
2 2 2013
(Recieve)
1 1 Jack
2 1 Ema
3 2 Alex
4 2 Sara
Result
1 1 2013 Jack, Ema
2 2 2013 Alex, Sara
I use this query in SqlServer (The DISTINCT keyword eliminates duplicate rows from the results of a SELECT statement)
SELECT DISTINCT c2.Id,
(SELECT STR( UserName )+ ','
FROM dbo.Reciver c1
WHERE c1.SendId = c2.id FOR XML PATH('')) Concatenated, c2.SendDate, c2.UserId
FROM dbo.Send AS c2 INNER JOIN
dbo.Reciver ON c2.Id = dbo.Reciver.SendId
How do this query in Linq?
Distinct is also available in LINQ.
For example
public class Product
{
public string Name { get; set; }
public int Code { get; set; }
}
Product[] products = { new Product { Name = "apple", Code = 9 },
new Product { Name = "orange", Code = 4 },
new Product { Name = "apple", Code = 10 },
new Product { Name = "lemon", Code = 9 } };
var lstDistProduct = products.Distinct();
foreach (Product p in list1)
{
Console.WriteLine(p.Code + " : " + p.Name);
}
Will return all rows.
var list1 = products.DistinctBy(x=> x.Code);
foreach (Product p in list1)
{
Console.WriteLine(p.Code + " : " + p.Name);
}
will return 9 and 4
It doesn't seem to me that you need to use Distinct in this Linq query. Assuming you have the relationships between tables set up on your linq datacontext, you can do something like this:
var result = from s in context.Send
select new {
id = s.Id,
userId = s.UserId,
date = s.SendDate,
users = s.Receive.Select(u => u.UserName)
}
Note: users will an IEnumerable<String> - you can use string.Join() on the client to join the names into a string.
Update
To return users as a string to first need to 'switch' to Linq To Objects by calling AsEnumerable() or ToList() and the Linq to Sql query.
var output = from s in result.AsEnumerable()
select new {
id = s.id,
userId = s.userId,
date = s.date,
users = string.Join(", ", s.users)
}
Also see Gert Arnolds answer for a good explanation.
What you want can only be done in two steps. Not because of the DISTINCT, but because of the FOR XML. The C# equivalent of the latter is String.Join(), but you can't use that in a linq to entities statement directly. So you must collect the required data first, then switch to linq to objects (by applying AsEnumerable) and then do the concatenation and distinct:
db.Sends
.Where(s => s.Receivers.Any())
.Select(s => new {
s.Id,
Concatenated = s.Receivers.Select(r => r.UserName)
s.SendDate,
s.UserId
})
.AsEnumerable()
.Select(x => new {
s.Id,
Concatenated = String.Join(", ", x.Concatenated)
s.SendDate,
s.UserId
})
.Distinct()
How do I convert this into a CriteraQuery:
select n
from TagRegistration t
join t.Tag n
where t.Status & :status > 0
order by count(t.ID) desc
, n.Name asc
Here's how you could do it with the criteria API:
[Flags]
enum Bar{
A = 0x01,
B = 0x02,
C = 0x04
}
var criteria = this.Session.CreateCriteria<Foo>()
.Add( BitwiseFlags.IsSet( "Bar", Bar.A | Bar.C ) );
using:
public class BitwiseFlags : LogicalExpression
{
private BitwiseFlags( string propertyName, object value, string op ) :
base( new SimpleExpression( propertyName, value, op ),
Expression.Sql( "?", value, NHibernateUtil.Enum( value.GetType() ) ) )
{
}
protected override string Op
{
get { return "="; }
}
public static BitwiseFlags IsSet(string propertyName, Enum flags)
{
return new BitwiseFlags( propertyName, flags, " & " );
}
}
should generate the following output where clause:
FROM _TABLE
WHERE (this_.Bar & 5 = 5)
which should give you rows that have flags Bar.A and Bar.C set (excluding everything else). You should be able to use it with conjunction and disjunction too.
Did something like that a while ago.
Try something like this.
PropertyProjection projection = Projections.Property("t.ID");
PropertyProjection property = Projections.Property("n.Namn");
ICriteria criteria = session.CreateCriteria<TagRegistration>("t")
.CreateCriteria("Tag","n")
.Add(
Restrictions.Gt(
Projections.SqlProjection("({alias}.ID & 3) as bitWiseResult", new[] { "bitWiseResult" }, new IType[] { NHibernateUtil.Int32 })
, 0)
)
.AddOrder(Order.Desc(Projections.Count(projection)))
.AddOrder(Order.Asc(property))
.SetProjection(Projections.GroupProperty(projection), Projections.GroupProperty(property))
Note this part {alias}.ID & 3) where I inserted the value directly which isn't very good but it works :)
You could do it better if you look at the test project of NHibernate
Nhibernate/Criteria/AddNumberProjection.cs
But you need to do a subQuery to return fully initialized Tag
I think this query is better to do in Hql.
Regards