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Spring Batch Paging with sortKeys and parameter values

I have a Spring Batch project running in Spring Boot that is working perfectly fine. For my reader I'm using JdbcPagingItemReader with a MySqlPagingQueryProvider.
#Bean
public ItemReader<Person> reader(DataSource dataSource) {
MySqlPagingQueryProvider provider = new MySqlPagingQueryProvider()
provider.setSelectClause(ScoringConstants.SCORING_SELECT_STATEMENT)
provider.setFromClause(ScoringConstants.SCORING_FROM_CLAUSE)
provider.setSortKeys("p.id": Order.ASCENDING)
JdbcPagingItemReader<Person> reader = new JdbcPagingItemReader<Person>()
reader.setRowMapper(new PersonRowMapper())
reader.setDataSource(dataSource)
reader.setQueryProvider(provider)
//Setting these caused the exception
reader.setParameterValues(
startDate: new Date() - 31,
endDate: new Date()
)
reader.afterPropertiesSet()
return reader
}
However, when I modified my query with some named parameters to replace previously hard coded date values and set these parameter values on the reader as shown above, I get the following exception on the second page read (the first page works fine because the _id parameter hasn't been made use of by the paging query provider):
org.springframework.dao.InvalidDataAccessApiUsageException: No value supplied for the SQL parameter '_id': No value registered for key '_id'
at org.springframework.jdbc.core.namedparam.NamedParameterUtils.buildValueArray(NamedParameterUtils.java:336)
at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.getPreparedStatementCreator(NamedParameterJdbcTemplate.java:374)
at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:192)
at org.springframework.jdbc.core.namedparam.NamedParameterJdbcTemplate.query(NamedParameterJdbcTemplate.java:199)
at org.springframework.batch.item.database.JdbcPagingItemReader.doReadPage(JdbcPagingItemReader.java:218)
at org.springframework.batch.item.database.AbstractPagingItemReader.doRead(AbstractPagingItemReader.java:108)
Here is an example of the SQL, which has no WHERE clause by default. One does get created automatically when the second page is read:
select *, (select id from family f where date_created between :startDate and :endDate and f.creator_id = p.id) from person p
On the second page, the sql is modified to the following, however it seems that the named parameter for _id didn't get supplied:
select *, (select id from family f where date_created between :startDate and :endDate and f.creator_id = p.id) from person p WHERE id > :_id
I'm wondering if I simply can't use the MySqlPagingQueryProvider sort keys together with additional named parameters set in JdbcPagingItemReader. If not, what is the best alternative to solving this problem? I need to be able to supply parameters to the query and also page it (vs. using the cursor). Thank you!

I solved this problem with some intense debugging. It turns out that MySqlPagingQueryProvider utilizes a method getSortKeysWithoutAliases() when it builds up the SQL query to run for the first page and for subsequent pages. It therefore appends and (p.id > :_id) instead of and (p.id > :_p.id). Later on, when the second page sort values are created and stored in JdbcPagingItemReader's startAfterValues field it will use the original "p.id" String specified and eventually put into the named parameter map the pair ("_p.id",10). However, when the reader tries to fill in _id in the query, it doesn't exist because the reader used the non-alias removed key.
Long story short, I had to remove the alias reference when defining my sort keys.
provider.setSortKeys("p.id": Order.ASCENDING)
had to change to in order for everything to work nicely together
provider.setSortKeys("id": Order.ASCENDING)

I had the same issue and got another possible solution.
My table T has a primary key field INTERNAL_ID.
The query in JdbcPagingItemReader was like this:
SELECT INTERNAL_ID, ... FROM T WHERE ... ORDER BY INTERNAL_ID ASC
So, the key is: in some conditions, the query didn't return results, and then, raised the error above No value supplied for...
The solution is:
Check in a Spring Batch decider element if there are rows.
If it is, continue with chunk: reader-processor-writer.
It it's not, go to another step.
Please, note that they are two different scenarios:
At the beginning, there are rows. You get them by paging and finally, there are no more rows. This has no problem and decider trick is not required.
At the beginning, there are no rows. Then, this error raised, and the decider solved it.
Hope this helps.

Hibernate query not returning correct value

So in my database, I have 3 rows, two rows have defaultFlag as 0 and one is set to 1, now in my processing am updating defaultProperty of one object to 1 from 0 but am not saving this object yet.
Before saving I need to query database and find if any row has defaultFlag set or not, there would be only 1 default set.
So before doing update am running query to find if default is set and i get 2 values out, note here if i go and check in db then there is only 1 row with default set but query gives me two result because this.object default property has changed from 0 to 1 but note that this object is not yet saved in database.
I am really confused here as to why hibernate query is returning 2 when there is one row with default set in database and other object whose default property has changed but it is not saved.
Any thoughts would be helpful. I can provide query if need be.
Update
Following suggestions, I added session.clear() to before running the query.
session.clear();
String sql = "SELECT * FROM BANKACCOUNTS WHERE PARTYID = :partyId AND CURRENCYID = :currencySymbol AND ISDEFAULTBANKACCOUNT= :defaultbankAccount";
SQLQuery q = session.createSQLQuery(sql);
q.addEntity(BankAccount.class);
q.setParameter("partyId", partyId);
q.setParameter("currencySymbol", currencySymbol);
q.setParameter("defaultbankAccount", 1);
return q.uniqueResult();
and it returns 1 row in result as expected but now am getting
nested exception is org.hibernate.NonUniqueObjectException: a different object with the same identifier value was already associated with the session exception

Either query which row has the "default flag" set before you start changing it, or query for a list of rows with default flag set & clear all except the one you're trying to set.
Very easy, stop mucking about with your "brittle" current approach which will break in the face of concurrency or if data is ever in an inconsistent state. Use a reliable approach instead, which will always set the data to a valid state.
protected void makeAccountDefault (BankAccount acc) {
// find & clear any existing 'Default Accounts', other than specified.
//
String sql = "SELECT * FROM BANKACCOUNTS WHERE PARTYID = :partyId AND CURRENCYID = :currencySymbol AND ISDEFAULTBANKACCOUNT= :defaultbankAccount";
SQLQuery q = session.createSQLQuery(sql);
q.addEntity(BankAccount.class);
q.setParameter("partyId", partyId);
q.setParameter("currencySymbol", currencySymbol);
q.setParameter("defaultbankAccount", 1);
//
List<BackAccount> existingDefaults = q.list();
for (BankAccount existing : existingDefaults) {
if (! existing.equals( acc))
existing.setDefaultBankAccount( false);
}
// set the specified Account as Default.
acc.setDefaultBankAccount( true);
// done.
}
This is how you write proper code, do it simple & reliable. Never make or depend on weak assumptions about the reliability of data or internal state, always read & process "beforehand state" before you do the operation, just implement your code clean & right and it will serve you well.

I think that your second query won't be executed at all because the entity is already in the first level cache.
As your transaction is not yet commited, you don't see the changes in the underlying database.
(this is only a guess)

That's only a guess because you're not giving many details, but I suppose that you perform your myObject.setMyDefaultProperty(1) while your session is open.
In this case, be careful that you don't need to actually perform a session.update(myObject) to save the change. It is the nominal case when database update is transparently done by hibernate.
So, in fact, I think that your change is saved... (but not commited, of course, thus not seen when you check in db)
To verify this, you should enable the hibernate.show_sql option. You will see if an Update statement is triggered (I advise to always enable this option in development phase anyway)

Query for task start and end dates in Activiti

I'm looking for a solution to query completed tasks in Activiti by filtering on the completion date. Because once they're finished completed task entries are being moved into the act_hi_taskinst table by the BPMN engine i would expected the required filters to be in the HistoricTaskInstanceQuery class. However there's nothing like startedAfter/startedBefore and finishedAfter/finishedBefore methods like in the HistoricProcessInstanceQuery. The table has the start_time_ and end_time_ columns so there's no reason why this kind of query would be not possible.
Is there an other way to filter by these properties or currently the only way to get around this is to query the act_hi_tasks table directly bypassing the Activiti engine?

Activiti provides Query API so there is no need to query act_hi_taskinst directly.
You query may look like this one
NativeHistoricTaskInstanceQuery taskQuery = historyService.createNativeHistoricTaskInstanceQuery();
taskQuery.sql("SELECT * FROM "+ managementService.getTableName(HistoricTaskInstance.class)+" WHERE start_time_=#{startTime} AND end_time_=#{endTime}");
taskQuery.parameter("startTime", startTime).parameter("endTime", end_time);
List<HistoricTaskInstance> tasks = taskQuery.list();

Activiti BPM get Variables within Task

is it possible to get all process or task variables using TaskService:
processEngine.getTaskService.createTaskQuery().list();
I know there is an opportunity to get variables via
processEngine.getTaskService().getVariable()
or
processEngine.getRuntimeService().getVariable()
but every of operation above goes to database. If I have list of 100 tasks I'll make 100 queries to DB. I don't want to use this approach.
Is there any other way to get task or process related variables?

Unfortunately, there is no way to do that via the "official" query API! However, what you could do is writing a custom MyBatis query as described here:
https://app.camunda.com/confluence/display/foxUserGuide/Performance+Tuning+with+custom+Queries
(Note: Everything described in the article also works for bare Activiti, you do not need the fox engine for that!)
This way you could write a query which selects tasks along with the variables in one step. At my company we used this solution as we had the exact same performance problem.
A drawback of this solution is that custom queries need to be maintained. For instance, if you upgrade your Activiti version, you will need to ensure that your custom query still fits the database schema (e.g., via integration tests).

If it is not possible to use the API as elsvene says, you can query yourself the database. Activiti has several tables on the database.
You have act_ru_variable, were the currently running processes store the variables. For the already finished processess you have act_hi_procvariable. Probably you can find a detailed explanation on what is on each table in activiti userguide.
So you just need to make queries like
SELECT *
FROM act_ru_variable
WHERE *Something*

The following Test, sends a value object (Person) to a process which just adds a few tracking infos for demonstration.
I had the same problem, to get the value object after execution the service to do some validation in my test.
The following piece of code shows the execution and the gathering of the task varaible after the execution was finished.
#Test
public void justATest() {
Map<String, Object> inVariables = new HashMap<String, Object>();
Person person = new Person();
person.setName("Jens");
inVariables.put("person", person);
ProcessInstance processInstance = runtimeService.startProcessInstanceByKey("event01", inVariables);
String processDefinitionId = processInstance.getProcessDefinitionId();
String id = processInstance.getId();
System.out.println("id " + id + " " + processDefinitionId);
List<HistoricVariableInstance> outVariables =
historyService.createHistoricVariableInstanceQuery().processInstanceId(id).list();
for (HistoricVariableInstance historicVariableInstance : outVariables) {
String variableName = historicVariableInstance.getVariableName();
System.out.println(variableName);
Person person1 = (Person) historicVariableInstance.getValue();
System.out.println(person1.toString());
}
}

Hibernate: Issues with running update query

I see there are two ways to create update query in Hibernate. First you can go with the standard approach where we have hql like:
Query q = session.createQuery("update" + LogsBean.class.getName() + " LogsBean " + "set LogsBean.jobId= :jobId where LogsBean.jobId= :oldValue ");
q.setLong("jobId", jobId);
q.setLong("oldValue", 0);
return q.executeUpdate();
or we can go and run
getHibernateTemplate.saveorupdate(jobId);
Now am getting java.lang.IllegalArgumentException: node to traverse cannot be null! on running first query and am not sure hwo to provide condition in getHibernateTemplate example, i want to update jobIds in log table whose value matches 0 and so i want to run something like
Update logs set jobId = 23 where jobId = 0
Above is the simple sql query that I am trying to run but I want to run this via hibernate, tried couple ways but it is not working, any suggestions?
Update:
As noted by Jeff, issue was not having space after update and so that issue got resolved but still values are not updated, i have updated show_sql true for hibernate and checking what could be the cause of the issue, will be running query generated by hibernate to run again db and see if records are updated.

Just a few things that might help you to resolve this:
What does .executeUpdate() return, 0 (as it did not update any
rows)?
Does it throw a HibernateException that you are
silently catching or rethrowing?
Which FlushMode do you have configured?
Does the update get to the DB? You could switch on the query log for your DB server.