I want to learn if we could write a query that has a condition like
List<Entity> findbyField1EqualsField2();
This method should not take any parameter . It should fetch entities which has a field1 equals field2. It is just a simple sql :
select * from entity where field1=field2.
But I could not find any solution yet. Thanks.
Create an operation with a query as next:
#Query("select t from entity t where t.field1 like t.field2")
List<T> findByField1LikeField2();
I don't think findByField1LikeField2()works.... you would need to do it passing a param findByField1Like(String param) and for this maybe you would need to load the entity before to get the value of field2.
Related
i would like to know if you have any idea how i can achieve this, considering a query stored as string in the configuration file.
I tried to use SqlQuery applied to the DBSet, but the problem is that SqlQuery requires me to select all properties of the required entities in my query. If i don't consider any column, it will complain because is not able to map the query to the entities.
I don't want to select all properties of the entities i want to query.
Thanks
If you are using EF then why not use Database.ExecuteSqlCommand()? It's in the System.Data.Entity namespace.
For example:
int result = db.Database.ExecuteSqlCommand("Non SELECT SQL etc...");
Well, I ended up implementing a mechanism using reflection that basically receives a group of fields to select, and constructs dynamic objects with those fields, so when applied the query with the joins between the entities, will only bring the fields I am looking for.
So, considering Entity1, Entity2, Entity3 with the following relationship
<b>Entity1</b>{
<br/> Entity1Name, <br/> List<*Entity2*> Entity2Items, <br/> etc..
<br/>}
and
<b>Entity2</b> { <br/> Entity2Name, <br/> List<*Entity3*> Entity3Items <br/>}
I can store e.g. the following query in the configuration file, and retrieve the information:
"Entity1.Entity1Name", <br/>
"Entity1.Entity2Items.Entity2Name", <br/>
"Entity1.Entity2Items.Entity3Items.Entity3Name"
Anyway, I was just trying to see if there would be any solution out-of-the-box that would require minimal code changes.
Thank you.
i need some help in formulating the correct JPQL query in Spring Data with JPA.
The usecase is:
Update a certain attribute of a bunch of Entities with a random value, and for every updated entity the random value must be different.
I tried this:
#Query("update Entity e set e.randomValue = " + UUID.randomUUID().toString())
void updateRandomValue()
This is pure JPQL, but the result is, that every Entity has now the same random value.
I could make it work with a native query query, but i really would like to have pure JPQL to be DB independent.
Any clue? Thanks!
I have a JPA repository custom query :
#Query("Select id, nom, code, codeComptable, typeClient from Client")
List<Object> findAllWithoutForeignKey();
This query returns a Java.Lang.Object :
[1, TEST X, GUHHR, 1566FR487, TypeClient{id=1, nom='GARAGE',
actif='true', dateDerniereModif='2015-01-03'}]
I don't know how to access the values of my object.
I have tried everything I could think of but I didn't manage to do that.
Does anyone know how to do?
Thanks.
Your JPQL query returns an Object array just as the JPA spec says it should. So you get each row and cast to Object[]. And then you access the elements of the array to get the column values. Basic java
A entity containing a HashMap (annotated with ElementCollection) will be persisted using Eclipse Link / JPA.
By using the following JPQL query the HashMap should be retrivied now:
SELECT t.myMap FROM myEntity t WHERE t.id = :id"
Unfortunately the result is not the Map again, but a list of Strings which are (only) the values of the HashMap.
How can I get the HashMap as a single result?
Any help is appreciated.
You can't. What you are asking for is not the collection in the entity, but elements from the join. The best you might get is to query for the entity and use its getMyMap() to get the collection you are after
I am trying to execute a namedquery
#NamedQuery(name="getEmployeeDetails",query="select e.username,e.email,e.image,e.firstname,e.lastname from Employee e where e.empid=?1")
Now when I execute this query in a EJB 3.0 Session Bean what is the object I should return.I tried returning Listits returning a Vector which creates a classcast exception.The employee table contains fields like password and other confidential details which I don't want to fetch.So I am not using select e from Employee e.
I am learning JPA can anyone help.
Below is the sample query which fetches only the required fields, but have to make such constructor for it.
Query : SELECT NEW package_name.Employee(e.username,e.email,e.image,e.firstname,e.lastname) FROM Employee e where e.empid=?1;
It will return Employee entity with selected fields & remaining will have default values.
Inspect the returned type by calling .getClass() on a returned object. I'd guess it's an array.
But this is not really a good way to use JPA. Select the whole entity and then just don't use what you don't need. It's not such a performance hit.