Hibernate JPA Template fetches list of objects from database.
Can this be type casted to another class object list??
List<Class1> list1 = (List<Class1>) getJpaTemplate().findByNamedQuery("..someQuery..");
This is the code which i use now. Class1 relates to a table1 in database. Will I be able to fetch the records in table1 into another list<Class2> list2; which has all parameters as table1 and some extra parameters. If I will be able to fetch then will I be able to assign values to those extra parameters through namedQuery ??
Any help appreciated!!
Yes, you can. But before you have some more concrete questions, go read the following:
Hibernate inheritance
and JPA-QL reference, point 7.7, where they explain cat.class
Related
I'm trying to make a N1QL based query on Spring Data Couchbase. The documentation says
#n1ql.fields will be replaced by the list of fields (eg. for a SELECT clause) necessary to reconstruct the entity.
My repository implementation is this one:
#Query("#{#n1ql.fields} WHERE #{#n1ql.filter}")
List<User> findAllByFields(String fields);
And I'm calling this query as follows:
this.userRepository.findAllByFields("SELECT firstName FROM default");
I'm getting this error:
Caused by: org.springframework.data.couchbase.core.CouchbaseQueryExecutionException: Unable to execute query due to the following n1ql errors:
{"msg":"syntax error - at AS","code":3000}
After a little bit of researching, I also tryed:
#Query("SELECT #{#n1ql.fields} FROM #{#n1ql.bucket} WHERE #{#n1ql.filter}")
With this query, I don't get an error, I get all the documents stored but only the ID the other fields are set to null, when my query tries to get the firstName field.
this.userRepository.findAllByFields("firstName");
Anyone knows how to do such a query?
Thank you in advance.
You're misunderstanding the concept, I encourage you to give the documentation more time and see more examples. I'm not sure what exactly you're trying to achieve but I'll throw some examples.
Find all users (with all of their stored data)
#Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter}")
List<User> findAllUsers();
This will basically generate SELECT meta().id,_cas,* FROM bucket WHERE type='com.example.User'
Notice findAllUsers() does not take any parameters because there are no param placeholders defined in the #Query above.
Find all users where firstName like
#Query("#{#n1ql.selectEntity} WHERE #{#n1ql.filter} AND firstName like $1")
List<User> findByFirstNameLike(String keyword);
This will generate something like the above query but with an extra where condition firstName like
Notice this method takes a keyword because there is a param placeholder defined $1.
Notice in the documentation it says
#{#n1ql.selectEntity} WHERE #{#n1ql.filter} AND test = $1
is equivalent to
SELECT #{#n1ql.fields} FROM #{#n1ql.bucket} WHERE
#{#n1ql.filter} AND test = $1
Now if you don't want to fetch all the data for user(s), you'll need to specify the fields being selected, read following links for more info
How to fetch a field from document using n1ql with spring-data-couchbase
https://docs.spring.io/spring-data/couchbase/docs/2.2.4.RELEASE/reference/html/#_dto_projections
I think you should try below query, that should resolve the issue to get fields based parameter you have sent as arguments.
Please refer blow query.
#Query("SELECT $1 FROM #{#n1q1.bucket} WHERE #{#n1ql.filter}")
List findByFirstName(String fieldName);
Here, bucket name resolve to the User entity and and n1ql.filter would be a default filter.
When generating facelets with CRUD functionality in JSF/JPA in Netbeans 7.3, variables are created in the annotations that specify the SQL statements used to update respective view. The variables are 's', 'f' and 'm'. Where are these variables declared? My assumption was that they would be part of a managed bean with a generous scope but I can't seem to find them.
What are these variables and where do they come from?
Solved. These 'variables' are so called range variables that are used in JPQL. When auto generated by Netbeans, an annotation like
#NamedQuery(name = "MyTable.findAll", query = "SELECT m FROM MyTable m")
gets a lower case range variable based on the initial letter of the entity being queried.
These can however be changed to a variable name of one's choice. For more information, read "10.2.3.3. JPQL Range Declarations" here:
http://docs.oracle.com/html/E24396_01/ejb3_langref.html
I want to use Jasypt with Hibernate in servlets. I refered Jasypt here. It says how to configure Hibernate. But, still it is not clear that how I can handle session to save & retrieve results. I did configurations of Hibernate as mentioned in above link(and I m not going to past them here again). Let me know how to save & retrieve data with Session.
For a simple example,lets say, I have a table called 'login' consisting 2 columns 'name','password'. column 'name' data type is varchar and 'password' is varbinary. The pojo class has variables String name and byte[] password. How can I save and retrieve data from table 'login'.At least any useful link which explain with sample codes ll be appreciated.
Edit
When I configured hibernate .hbm file & try to save as usual, an exception is also thrown.
There are a lot of examples over the net which describe how to call a stored procedure using Hibernate, however, when using Spring, the picture changes a bit.
I have a stored procedure in MySQL which I want to call:
in SQL I need to write the following:
CALL inrange(32.342324,32.234234);
It returns a row with the following: `{INT},{INT},{FLOAT}`
With Spring, I use the HibernateTemplate way of executing hibernate operations, I know that some of you won't like it, but this is the how the project was when I started, and I'm not so eager changing it, maybe in the future...
Currently, I have the following code in Java, which tries to call the procedure:
List<Object[]> resultset = hibernateTemplate
.findByNamedQuery("inrange",
person.getAddress().getLatitude(),
person.getAddress().getLongitude());
When I run it, I get the following Hibernate exception:
org.springframework.orm.hibernate3.HibernateSystemException:
Named query not known: inrange;
I figured that this is happening duo the fact that I didn't declare the stored procedure in hibernate.
My question is:
how do I declare it ?
Is there a special way of declaring it in the Spring's application context file ?
You can call native sql queries within hibernate.
Look at this link:
http://www.mkyong.com/hibernate/how-to-call-store-procedure-in-hibernate/
Btw if you want to call stored procedures you could simply use a Spring JdbcTemplate.
Notice that an hibernate extension can fit to your needs:
http://www.hibernatespatial.org/
You're confusing Hibernate's named queries with MySQL's stored procedures.
If you want to call the MySQL stored proc, there is no benefit to doing so through Hibernate's API. I recommend you use Spring's JdbcTemplate to perform the query.
If you absolutely must use Hibernate, something like this should work:
SQLQuery query = hibernateTemplate.getCurrentSession()
.createSQLQuery("SELECT inrange(:latitude, :longitude)";
query.setDouble("latitude", ...);
query.setDouble("longitude", ...);
List<Object[]> result = query.list(); // requires casting for generics
You need to add the named query to your hibernate mapping file.
Can you share your hibernate mapping file? You can find some samples here.
Along with the previous link you can go through this also.
It will be easier if you can share the POJO, hibernate mapping and the procedure you are using.
This blog will be of help for you. I hope you will not have any problem with using the getHibernateTemplate().execute(HibernateCallback) method.
You can use JPA as Spring supports it either in Core or Spring Data.
Calling the stored procedure can be done using the StoredProcedureQuery as follows:
StoredProcedureQuery query = entityManager
.createStoredProcedureQuery("count_comments")
.registerStoredProcedureParameter(
"postId", Long.class, ParameterMode.IN)
.registerStoredProcedureParameter(
"commentCount", Long.class, ParameterMode.OUT)
.setParameter("postId", 1L);
query.execute();
Long commentCount = (Long) query
.getOutputParameterValue("commentCount");
I am trying to do a simple query to get a unique result back in hibernate here is my code.
public String getName(Integer id) {
Session session = getSessionFactory().openSession();
String name = (String)session.createSQLQuery("SELECT name FROM users WHERE user_id = :userId").setParameter("userId", id).uniqueResult();
return name;
}
The name that is being returned is stored as HTML text that includes html syntacx language. I think this is what is causing the problem but it doesnt make sense I just want to return it as a string.
It is only happening on this one field name, I can get every other field in the row but this one it gives me the error.
I am getting an exception. The exception I am getting is
No Dialect mapping for JDBC type: -1; nested exception is org.hibernate.HibernateException
How do you query for a specific column on a row in hibernate?
I figured out the solution, apparently Java has not type that can be mapped to Text fields so you have to add a scalar solution below: Thanks for the help
session.createSQLQuery("SELECT name FROM users WHERE user_id = :userId").addScalar("name", Hibernate.TEXT).setParameter("userId", id).uniqueResult();
Then that should work. Use the Type hibernate annotation.
Add
#Type(type="text")
To your mapping.