I want fetch last record using hibernate criteria
Can u help me?
What do you mean by hibernate criteria in mySQL?
hibernate criteria is used in java to retrieve persistant class objects.
in my SQL you can run following query
SELECT col1, col2, ... FROM yourtable ORDER BY xyz DESC LIMIT 1
Related
SQL :
String hql1 = "SELECT /* PARALLEL(MVR,16) PARALLEL(MVRS,16)*/ * FROM
ICM MINUS SELECT I1.* FROM ICM I1 , C1_ICM_STATIC I2 WHERE
I1.METRIC_DIRECTION=I2.METRIC_DIRECTION AND
I1.METRIC_NAME=I2.METRIC_NAME AND I1.METRIC_UNIT=I2.METRIC_UNIT AND
I1.TERMINATION_POINT_ID=I2.TERMINATION_POINT_ID AND
I1.TERMINATION_POINT_NAME=I2.TERMINATION_POINT_NAME AND
I1.TERMINATION_POINT_TYPE=I2.TERMINATION_POINT_TYPE";
Criteria Query
icms1 = (List<ICM>) session.createCriteria(ICM.class, hql1).list();
I have executed hql1 using SQL Developer then I got only one result, but when I have integrated SQL Query with Criteria it returning me all records in ICM table.
If SQL query returning only one result in SQL Developer, Why criteria API returning all records in ICM table?
Why criteria API returning all records in ICM table?
Technically you are not using criteria api for associations.
Try something like this.
Refer.
return criteria.createCriteria(A.class)
.createCriteria("b", "join_between_a_b")
.createCriteria("c", "join_between_b_c")
.createCriteria("d", "join_between_c_d")
.add(Restrictions.eq("some_field_of_D", someValue));
You should learn to read API documentation.
The second Session.createCriteria() argument is the alias that you want to assign to the root entity. It's not a HQL query. HQL queries are not executed using Session.createCriteria(). They're executed using Session.createQuery().
BTW, your query is not a HQL query at all. It's a SQL query. SQL and HQL are 2 different languages. To execute a SQL query, you need createSQLQuery().
I have 2 tables TABLE1 and TABLE2.Table1 is having name and Table2 is having email and Phone.
To get the name,email and phone,I query as below
query = entityManagerUtil.createNativeQuery("select s.Name,c.Phone1,c.Email1 from Table1 s,Table2 c where c.id= s.NodeID and s.NodeID =21")
Now my next requirement is to update name,email and phone.As these parameters are present in different tables so I am searching for single query which will update 2 tables.Unfortunately I am using sql server and there is no way to update 2 tables using single query
So I am thinking to use #Transactional and 2 queries to update 2 tables like the follow
#Transactional
public void updateDetails()
{
Query query1= entityManagerUtil.entityManager.createNativeQuery("update Table1 set Name='' where id in (select NodeID from Table 2) and NodeID=21");
Query query2= entityManagerUtil.entityManager.createNativeQuery("update Table2 set Email='' and phone1='' where NodeID in (select id from Table 2) and NodeID=21");
query1.executeUpdate();
query2.executeUpdate();
}
Is there any other better way to update 2 tables?
you can use JDBCTemplate
http://sujitpal.blogspot.com.es/2007/03/spring-jdbctemplate-and-transactions.html
It allows to do multiple queries with one connection, so you save some time instead of doing it twice.
Why don't you use Hibernate entities for that. Just load the entities associated with Table1 and table2, modify them and let the automatic dirty checking mechanism to update the tables on your behalf. That's one reason for using an ORM by the way.
How would represent the following Oracle SQL in Hibernate HQL.
select table_num
, room_id
, min(event_type) keep(dense_rank first order by changed_on desc)
from room_history
group by table_num, room_id;
The idea behind the query is to order the table "room_history" by "changed_on" datetime column and then group it by "table_num" and "room_id" pairs whilest keeping the first "event_type" for each group. The mentioned query works for Oracle but I have trouble converting it into HQL.
Purpose is to get the latest "event_type" for "table_num" and "room_id" pair.
It seems this is not achievable
I ended up converting the following SQL query instead. It is not perfect but it does the job for my purposes.
select table_num, event_type et from room_history where id in (select max(id) from privacy_history group by msisdn);
I was able to do this assumptions since when for this table always a.id > b.id then also a.changed_on> b.changed_on.
I've successfully created some JPA 2 criteria queries, but im now converting a query that is too complex for me to be able to convert it. Anyone up for a challenge? I will be eternally thankful for any response! :)
This is the query in plain SQL (mysql):
SELECT o.orderId, oi.insertDate
FROM AIDA_ORDER o
LEFT OUTER JOIN
(SELECT orderId, MIN(insertDate) AS insertDate FROM AIDA_ORDER_INSERT
WHERE insertDate > CURDATE() GROUP BY orderId) AS oi
ON oi.orderId = o.orderId
ORDER BY oi.insertDate, o.orderId;
The AIDA_ORDER table corresponds to a OrderBean, and AIDA_ORDER_INSERT to a OrderInsertBean.
A AIDA_ORDER can have multiple AIDA_ORDER_INSERTS.
Excuse me for anking again about this issue but I need to have a JPA query for this:
select username, count(*)
from Records
group by username
order by count(*) desc
limit 1
I thought about smth like:
select r.username,count(*) from Records r order by r.username desc
and then to call
getResultList().get(0)
but I am allowed to write only:
select r from Records r order by r.username desc
and in this case I do not know how to get what I need.
Does anyone have any idea?
The SQL query has a group by, and orders by count. The JPA query doesn't have any group by and orders by user name. So I don't see how they could return the same thing.
The equivalent JPQL query is
select r.username, count(r.id)
from Record r
group by r.username
order by count(r.id) desc
If you call setMaxResults(1) on the Query object, the limit clause will be added to the generated SQL query, making it completely equivalent.