I have the following code:
String SQL_QUERY ="Select abstractDesc from article";
Query query = session.createSQLQuery(SQL_QUERY);
Object [] amount = (Object []) query.uniqueResult();
out.println("mean amount: " + amount[0]);
but I get the following error:
Hibernate: Select abstractDesc from article
query did not return a unique result: 10
How can I solve this to have the query executed and print the result properly?
As you are using uniqueResult(), you are telling Hibernate that you are expecting only a single value.
Check your database or replace uniqueResult() with [list()]1 to see what you get back.
Related
I'm using EclipseLink as JPA implementation and I need to get multiple objects using the primary key (numeric id). But I also need to maintain the given id order.
Using native mySQL this kind of behaviour can be obtained using ORDER BY FIELD
SELECT id FROM table WHERE id IN(9,5,2,6) ORDER BY FIELD(id,9,5,2,6);
I'm now trying to replicate this query using JPA implementation. As already established from this thread, the ORDER BY FIELD is not supported, so I went to a more low-level approach using a JPA native query.
I'm try to reach this goal using a parameter query, instead of using a raw statement. The first implementation was like this
Class<?> clazz = ...;
List<Long> ids = ...;
EntityManagerFactory emf = ...;
EntityManager em = emf.createEntityManager();
String statement = "SELECT * FROM table WHERE id IN (?)";
Query createNativeQuery = em.createNativeQuery(statement, clazz);
createNativeQuery.setParameter(1, ids);
List resultList = createNativeQuery.getResultList();
As you can see the ORDER clause is not there yet, for the first step I just trying to make the parameter query work using the ids list with the IN operator. In the setParameter method I tried to provide the List object, a comma separated list (as string) but none of them works. At the end they all finish with a sql syntax error.
I also tried to play with the parenthesis, with or without, but nothing works.
Here some test I made
String statement = "SELECT * FROM " + tableName + " WHERE id IN (?)";
Query createNativeQuery = emJpa.createNativeQuery(statement, this.em.getClassObject());
createNativeQuery.setParameter(1, ids);
The query does not give any error, but no results given.
String statement = "SELECT * FROM " + tableName + " WHERE id IN (?)";
Query createNativeQuery = emJpa.createNativeQuery(statement, this.em.getClassObject());
createNativeQuery.setParameter(1, Joiner.on(",").join(ids));
Only one result is given, but 7 ids was provided to the query
From this topic I also tried using ?1 instead of ?, but no changes. Is there a way to make the nativeQuery working with a list of ids?
For the moment I'm using the full raw SQL statement
String joinedId = Joiner.on(",").join(ids);
String statement = "SELECT * FROM " + tableName + " WHERE id IN (" + joinedId + ") ORDER BY FIELD(id," + joinedId + ")";
Query createNativeQuery = emJpa.createNativeQuery(statement, this.em.getClassObject());
createNativeQuery.getResultList();
But at first I started with the parameter query for optimization and performance related of parsing each time the statement.
EDIT
With the suggestion of Chris I tried a TypedQuery using the FUNCTION operator (which is available because I'm using the latest EclipseLink). Here is the resulting code
List<Long> ids = ...;
Class<?> clazz = ...;
String statement = "SELECT e FROM " + clazz.getSimpleName() + " e WHERE e.id IN (:idList) ORDER BY FUNCTION('FIELD', e.id, :idList)";
EntityManagerFactory emf = ...;
EntityManager em = emf.createEntityManager();
TypedQuery<?> query = em.createQuery(statement, clazz);
query.setParameter("idList", ids);
List resultList = query.getResultList();
And here is the error while executing this code
Local Exception Stack:
Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: Operand should contain 1 column(s)
Error Code: 1241
Call: SELECT ... all the fields ... FROM webcontent_type WHERE (ID IN ((?,?,?,?,?,?,?))) ORDER BY FIELD(ID, (?,?,?,?,?,?,?))
bind => [14 parameters bound]
Query: ReadAllQuery(referenceClass=WebContentType sql="SELECT ... all the fields ... FROM webcontent_type WHERE (ID IN (?)) ORDER BY FIELD(ID, ?)")
EDIT 2
Tried without the parenthesis but there is still an error
SELECT e FROM FrameWorkUser e WHERE e.id IN :idList ORDER BY FUNCTION('FIELD', e.id, :idList)
I must say that with a list of one element the code works, but with another list of 10 elements there is an error
javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLException: Operand should contain 1 column(s)
Error Code: 1241
Call: SELECT .... FROM webcontent_type WHERE (ID IN (?,?,?,?,?,?,?)) ORDER BY FIELD(ID, (?,?,?,?,?,?,?))
bind => [14 parameters bound]
Query: ReadAllQuery(referenceClass=WebContentType sql="SELECT .... FROM webcontent_type WHERE (ID IN ?) ORDER BY FIELD(ID, ?)")
at org.eclipse.persistence.internal.jpa.QueryImpl.getDetailedException(QueryImpl.java:382)
at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:260)
at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:473)
It seems that even w/o the parenthesis, the resulting statement has them
If you are going to use a native query, you must do it exactly like you would form the SQL for your database - this means you must break the list into its component parameters as JPA providers are not expected to change the SQL for you. Most providers handle lists in JPQL though, so "select e from Entity e where e.id in (:idList)" will work in EclipseLink.
Your missing bit is that 'FIELD' is not a JPQL construct. For this, you would have to use the JPQL 2.1 FUNCTION operator. Something like:
"Select e from Entity e where e.id in :idList order by FUNCTION('FIELD', e.id, :idList)"
I am getting the following error on the execution of the below hibernate transaction : expecting DOT, found '=' near line 1, column 32 [update t_credential set status = :status , assigned_engine = :engine where id = :id] .
Also, t_credential is a table and not an object. Does hibernate allow to use this way or does it compulsorily have to be an object?
for(Credential credential: accountList){
Query query = ssn.createQuery("update t_credential set status =:status , assigned_engine = :engine where id = :id");
query.setParameter("status", status);
query.setParameter("engine", assignedTo);
query.setParameter("id", String.valueOf(credential.getId()));
int result = query.executeUpate();
}
Look at the HQL example here: http://docs.jboss.org/hibernate/orm/3.3/reference/en/html/batch.html#batch-direct. It seems that you need to refer to an object: "update t_credential c", and then update it's fields, like this: "set c.status = :status" and so on.
If you want to use Hibernate with SQL Query (and not HQL query), you may have to use a different function.
ssn.createSQLQuery(" ... ");
I never used this function, so I hope it's a good answer for you.
Max
Below is the stored procedure:
create or replace procedure
proc_emp_name(v_emp out emp.emp_name%TYPE, v_empid in emp.emp_id%TYPE)
is
begin
select emp_name into v_emp from emp where emp_id = v_empid;
dbms_output.put_line('Emp Name: ' || v_emp);
dbms_output.put_line('Procedure created successfully!!!');
end;
I want to invoke this using Native SQL, followed this link but not sure how to retrieve the OUT parameter from the Procedure.
http://www.mkyong.com/hibernate/how-to-call-store-procedure-in-hibernate/
Kindly let me know the simplest way to invoke the procedure and get the results out of it.
EDIT
As suggested, checking the docs, I modified the Proc having first parameter as a SYS_REFCURSOR as follows:
create or replace procedure
proc_empname_refcursor(v_empname OUT SYS_REFCURSOR, v_deptid in emp.emp_id%type)
is
begin
open v_empname for select * from dept where dept_id = v_deptid;
end;
I am able to invoke it using NamedQuery but I don't want to add anything in the mapping files because of some other restrictions. I tried the below code for invoking the proc without using NamedQuery but it did not worked out:
Query query = session.createSQLQuery(
"CALL proc_empname_refcursor(?, :deptId)")
.addEntity(Dept.class)
.setParameter("deptId", new Integer(2));
List<Dept> departments = query.list();
for(int i=0; i<departments.size(); i++){
Dept department = (Dept)departments.get(i);
System.out.println("Dept Id: " + department.getDeptId());
System.out.println("Dept Name: " + department.getDeptName());
}
I am getting the exception:
org.hibernate.QueryException: Expected positional parameter count: 1, actual parameters: [] [CALL proc_empname_refcursor(?, :deptId)]
at org.hibernate.impl.AbstractQueryImpl.verifyParameters(AbstractQueryImpl.java:319)
at org.hibernate.impl.SQLQueryImpl.verifyParameters(SQLQueryImpl.java:201)
at org.hibernate.impl.SQLQueryImpl.list(SQLQueryImpl.java:145)
at com.jdbc.HibernateStartup.main(HibernateStartup.java:70)
Kindly let me know how to resolve this.
I've managed to get an out parameter from a stored procedure using the following code in Hibernate and MS SQL Server:
#Override
public Serializable generate(SessionImplementor session, Object object) throws HibernateException {
Connection connection = session.connection();
CallableStatement callable = null;
try {
callable = connection.prepareCall("execute [procedure] ?");
callable.registerOutParameter(1, Types.INTEGER);
callable.execute();
int id = callable.getInt(1);
return id;
} catch (SQLException e) {
(...)
} finally {
(...)
}
}
From Hibernate Docs:
You cannot use stored procedures with Hibernate unless you follow some procedure/function rules.
For Oracle, A function must return a result set. The first parameter of a procedure must be an OUT that returns a result set.
I'm trying to fetch the last entity that was inserted into the database, which I thought would be a very simple thing to do, but every query i try results in some sort of exception to get thrown
The code im using is:
#Override
public DataStoreMark getLastMark() {
String selectQuery = "from Mark";
Query query = em.createNativeQuery(selectQuery, DataStoreMark.class);
try {
return (DataStoreMark) query.getSingleResult();
} catch (NoResultException e) {
log.error("Couldn't find any Marks in the DataStore.");
}
return null;
}
This code however throws a PesistenceException:
org.hibernate.exception.SQLGrammarException: You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near 'from milestone' at line 1
And there is definitely a record in the database.
Any ideas?
You can use either of createQuery() and createSqlQuery() if it does not work:
1.
String selectQuery = "from Mark";
Query query = em.createQuery(selectQuery);
return (DataStoreMark) query.list().get(0);
2.
String selectQuery = "select * from Mark";
SQLQuery query = (SQLQuery) em.createSQLQuery(selectQuery);
query.addEntity(DataStoreMark.class);
return query.list();
I think hibernate does not tell about last entity added to the database. Alternatively you can write the query specific to your db and run it using createSqlQuery() as shown above.
i have below code snippet. It throws the exception at line 3 but query works fine managemnt studio(sql server 2005)
String query = "select * from user where userId=" + profileId
+ " and spaceName='" + spaceName + "'";
Session session = HibernateUtil.getSession();
List<PersonDetailsData> personDetailsData = new ArrayList<PersonDetailsData>(
session.createQuery(query).list()); //line 3
Here is the exception
org.hibernate.hql.ast.QuerySyntaxException: unexpected token: * near
line 1, column 8 [select * from user where userId=216 and
spaceName='DIG']
I am not able to figure out what's the problem with query when it is running fine in management sudio?
It's native query, not hql.
If you have mapped table field to class fields you need
session.createSQLQuery(query, PersonDetailsData.class).list();
or create hql type query -
select p from PersonDetailData p where p.userId = :userId and p.spaceName =:spaceName
and use parameters in query, not direct values.
As you are using sql query so you have to create a sql query such as
sess.createSQLQuery("SELECT * FROM CATS").list();
see the source source