NHibernate: Get object by SQL Query - sql

Is it possible to do something like this in NHibernate?
Product GetSpecificProduct()
{
return session.CreateSQLQuery("SELECT * FROM Products WHERE price =
$500").UniqueResult<Product>();
}
When I try to run this code I get:
System.InvalidCastException: Unable to cast object of type 'System.Object[]' to type Product.
Or do I have to use the NHibernate query language ?

If you have to use CreateSqlQuery, you can use the following:
Product GetSpecificProduct()
{
ISQLQuery query = session.CreateSQLQuery("SELECT * FROM Products WHERE price = $500");
Product p = query.SetResultTransformer(Transformers.AliasToBean<Product>()).UniqueResult<Product>();
}
I suggest you better use ICriteria as in:
Product GetSpecificProduct()
{
ICriteria c = session.CreateCriteria();
c.Add(Expression.Eq("Price", 500));
return c.UniqueResult<Product>();
}

Yes you can. Check out Entity Queries using Native SQL : http://codewut.de/content/using-native-sql-nhibernate

Related

Transforming Raw Sql to Laravel equolent

I have written this SQL code
SELECT drugs.*, COUNT(*) as 'views' from drugs INNER JOIN drug_seen on drugs.id = drug_seen.drug_id GROUP BY drugs.id order by views ASC
And now I am trying to write in in the Laravel equolent but I am facing some troubles.
This is what I have tried
$drugs = Drug::select(DB::raw('drugs.*,count(*) as views'))
->join('drug_seen', 'drugs.id', 'drug_seen.drug.id')
->groupBy('drug.id')->orderByRaw('views');
I am having errors like column not found i think the code is not written properly
Drug class
class Drug extends Model
{
use HasFactory;
use SoftDeletes;
...
...
...
public function drugVisits()
{
return $this->hasMany(DrugSeen::class);
}
Hop this will solve your problem.
$drugs = Drug::with('drugVisits')->get();
$drugs->count(); //for total records in drugs table.
You have typo error in join instead on drug_id you use drug.id
Try this:
$drugs = Drug::select(DB::raw('drugs.*,count(*) as views'))
->join('drug_seen', 'drugs.id', 'drug_seen.drug_id')
->groupBy('drugs.id')->orderByRaw('views');
}
As soon as you use join() you're leaving Eloquent and entering Query\Builder, losing the benefits of Model configurations in the process. And with() eager-loads aren't the answer, if you're looking to filter the results by both tables. What you want is whereHas().
Also, as far as your grouping and count manipulation there, I think you're looking more for Collection handling than SQL groups.
$drugModel = app(Drugs::class);
$results = $drugModel->whereHas('drugVisits')->with('drugVisits')->get();
$organizedResults = $results
->groupBy($drugModel->getKey())
->sortyBy(function (Drugs $drugRecord) {
return $drugRecord->drugVisits->count();
});
If you want to have a 'views' property that carries the count in the root-level element, it would look like this:
$drugModel = app(Drugs::class);
$results = $drugModel->whereHas('drugVisits')->with('drugVisits')->get();
$organizedResults = $results
->groupBy($drugModel->getKey())
->map(function (Drugs $drugRecord) {
$drugRecord->views = $drugRecord->drugVisits->count();
return $drugRecord;
});
->sortyBy('views');

How to map ONE-TO-MANY native query result into a POJO class using #SqlResultSetMapping

Im working in a backend API using Java and MySql, and I'm trying to use #SqlResultSetMapping in JPA 2.1 for mapping a ONE-TO-MANY native query result into a POJO class, this is the native query:
#NamedNativeQuery(name = "User.getAll”, query = "SELECT DISTINCT t1.ID, t1.RELIGION_ID t1.gender,t1.NAME,t1.CITY_ID , t2.question_id, t2.answer_id FROM user_table t1 inner join user_answer_table t2 on t1.ID = t2.User_ID“,resultSetMapping="userMapping")
And, here is my result SQL mapping:
#SqlResultSetMapping(
name = "userMapping",
classes = {
#ConstructorResult(
targetClass = MiniUser.class,
columns = {
#ColumnResult(name = "id"),
#ColumnResult(name = "religion_id"),
#ColumnResult(name = "gender"),
#ColumnResult(name = "answers"),
#ColumnResult(name = "name"),
#ColumnResult(name = "city_id")
}
),
#ConstructorResult(
targetClass = MiniUserAnswer.class,
columns = {
#ColumnResult(name = "question_id"),
#ColumnResult(name = "answer_id")
}
)
})
And, here is the implementation of the POJO classes: (I just removed the constructor and the getters/setter)
MiniUser class
public class MiniUser {
String id;
String religionId;
Gender gender;
List<MiniUserAnswer> answers;
String name;
String city_id;
}
and the MiniUserAnswer class
public class MiniUserAnswer {
String questionId;
String answerId;
}
My goal is to execute this Query and return a list of MiniUser, and in each MiniUser: a list of his “answers", which is a list of MiniUserAnswer.
after running this code, I got this error:
The column result [answers] was not found in the results of the query.
I know why, it's because there is no “answers" field in the query select statement.
So, how can I accomplish something like this, considering the performance? This answers list may reach 100.
I really appreciate your help, Thanks in advance!
The query "SELECT DISTINCT t1.ID, t1.RELIGION_ID t1.gender, t1.NAME, t1.CITY_ID, t2.question_id, t2.answer_id" does not return a parameter called answers.
To obtain the result you are looking for I would use:
Option 1 (Criteria Builder)
CriteriaBuilder cb = entityManager.getCriteriaBuilder();
CriteriaQuery<UserTableEntity> cq = cb.createQuery(UserTableEntity.class);
Root<UserTableEntity> rootUserTable = cq.from(UserTableEntity.class);
Join<UserTableEntity,UserAnswerTableEntity> joinAnswerTable = rootUserTable.join(rootUserTable_.id) // if the relationship is defined as lazy, use "fetch" instead of "join"
//cq.where() NO WHERE CLAUSE
cq.select(rootUserTable)
entityManager.createQuery(cq).getResultList();
Option 2 (Named query, not native)
#NamedQuery(name = "User.getAll”, query = "SELECT t1 FROM UserTableEntityt1 join fetch t1.answers)
Option 3 (Entity subgraph, new in JPA 2.1)
In User Entity class:
#NamedEntityGraphs({
#NamedEntityGraph(name = "graph.User.Answers", attributeNodes = #NamedAttributeNode("answers"))
})
In DAO set hints in the entity manager:
EntityGraph graph = this.em.getEntityGraph("graph.User.Answers");
Map hints = new HashMap();
hints.put("javax.persistence.fetchgraph", graph);

Criterion based on boolean TSQL function

I'm calling the sql server function Contains like this :
ftquery = _OrElse(ftquery,Restrictions.Eq(Projections.SqlFunction("contains",NHibernateUtil.Boolean, Projections.Property<Document>(d => d.SearchContent), Projections.Constant(query.Query)),true));
OrElse will juste do an or using Restrictions.Or(ICriterion, ICriterion). The problem is that it generates invalid sql :
... and contains(this_.SearchContent, ?) = ? ORDER BY ...
I don't want to have the right part ( = ? ), I only need the Projection without the Restrictions.Eq, but without Restrictions.Eq I can't find any solution to convert a Projection to a Criterion.
How can we using NHibernate generate an sql like :
Select Name from Users where Contains(Name,'toto') or Contains(Job,'tata')
Register the function in your dialect:
RegisterFunction("FullTextContains", new StandardSQLFunction("contains", NHibernateUtil.Boolean));
Create a projection using Projections.SqlFunction then use this ProjectionAsCriterion class on your query:
var projection = Projections.SqlFunction("FullTextContains",
NHibernateUtil.Boolean,
Projections.Property<Document>(x => x.SearchContent),
Projections.Constant(query.Query));
var result = Session.QueryOver<Document>()
.Where(new ProjectionAsCriterion(projection))
.List();

Entity Framework - attribute IN Clause usage

I need to filter some Entities by various fields using "normal" WHERE and IN clauses in a query over my database, but I do not know how to do that with EF.
This is the approach:
Database table
Licenses
-------------
license INT
number INT
name VARCHAR
...
desired SQL Query in EF
SELECT * FROM Licenses WHERE license = 1 AND number IN (1,2,3,45,99)
EF Code
using (DatabaseEntities db = new DatabaseEntities ())
{
return db.Licenses.Where(
i => i.license == mylicense
// another filter
).ToList();
}
I have tried with ANY and CONTAINS, but I do not know how to do that with EF.
How to do this query in EF?
int[] ids = new int[]{1,2,3,45,99};
using (DatabaseEntities db = new DatabaseEntities ())
{
return db.Licenses.Where(
i => i.license == mylicense
&& ids.Contains(i.number)
).ToList();
}
should work

How to eager fetch join table collection in Hibernate Native SQL Query?

I have following three database tables
Customer
Product
CustomerProductRelation
Corresponding to these tables, I have two Hibernate POJO's
Product
Customer
One of the member variable is a joinTable:
#JoinTable(name = "CustomerProductRelation", joinColumns = { #JoinColumn(name = "CUSTOMER_ID") }, inverseJoinColumns = { #JoinColumn(name = "PRODUCT_ID") })
private List<Product> products;
Due to some reason, I need to use a native SQL query on Customer table, in that case how do I eager fetch products in my customer list?
I am doing something similar to this:
String queryString = "select c.*,cpr.product_id from Customer c, CustomerProductRelation cpr where c.customer_id = cpr.customer_id";
List list = getSession().createSQLQuery(queryString)
.addEntity("c", Customer.class)
.addJoin("p", "c.products").list();
This does not seem to work. The exception is as follows:
java.lang.NullPointerException at org.hibernate.loader.DefaultEntityAliases.<init>(DefaultEntityAliases.java:37) at org.hibernate.loader.ColumnEntityAliases.<init>(ColumnEntityAliases.java:16) at org.hibernate.loader.custom.sql.SQLQueryReturnProcessor.generateCustomReturns(SQ‌​LQueryReturnProcessor.java:264)
Please let me know if anyone knows the solution to this.
Is this what you are seeing? (HHH-2225)