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How to fetch list of tables in database using HibernateDaoSupport?

Here I have added my code. Issue occurs in try block while I am trying fetch list of tables.
Database is MySql
Exception is : java.lang.IllegalArgumentException: node to traverse cannot be null!
public class DBOptimizationDAO extends HibernateDaoSupport {
private static final Log log = LogFactory.getLog(DBOptimizationDAO.class);
public void optimizeAdapter(String year)
{
List<com.ecw.adapterservice.beans.TransactionInbound> transactionInboundList = null;
StringBuilder queries = new StringBuilder();
try {
transactionInboundList = (List<com.ecw.adapterservice.beans.TransactionInbound>)super.getHibernateTemplate().find("from TransactionInbound where inboundTimestamp < '" + year+ "-01-01'order by 1 desc limit 2");
// Check if archive table exist or not
List<Object> inboundObj = getHibernateTemplate().find("SHOW TABLES LIKE transaction_outbound");
List<Object> outboundObj = getHibernateTemplate().find("SHOW TABLES LIKE 'transaction_outbound_archive'");

The HibernateTemplate::find expects a HQL query in the string parameter and you are passing a native statement. You can do native stuff (queries, statements, etc) using the Session object returned by HibernateTemplate::getSession. To pass a native select query you then have Session::createSQLQuery
BUT do you really want to rely on database specific code to do this? There is a more elegant way to do it by using DatabaseMetaData::getTables. See this answer. And you can get an instance of DatabaseMetaData from a callback method of your HibernateTemplate.
Try this:
Session session = getHibernateTemplate().getSessionFactory().getCurrentSession();
if(!session instaceof SessionImpl){
//handle this, maybe throw an exception
}
else {
Connection con = (SessionImpl)session.connection();
...
}

JPA Select Query with composite primary key leads an exception

I have tried the below code for getting the single NotificationSubType Object. But finding exception like " org.apache.openjpa.persistence.ArgumentException: Encountered "from" at character 1, but expected: ["DELETE", "SELECT", "UPDATE"]."
Please help me on given problem.
Code is given below :
...
...
try {
Query query = this.em.createQuery("from NotificationSubType conc WHERE conc.id.alertTyC = ?1 and conc.id.alertSubTyC = ?2");
query.setParameter(1, "MPPRINT");
query.setParameter(2, "REIN");
NotificationSubType trackIdResLst = (NotificationSubType)query.getSingleResult();
if (null != trackIdResLst) {
System.out.println("TRUE");
} else{
System.out.println("FALSE");
}
} catch (Exception e) {
NotificationLogger.errorWithThrowable(e);
throw new NotificationServiceException(e.getMessage());
}
...

Why not read the exception? and read the JPA spec ?
JPQL statements have to start with SELECT, UPDATE or DELETE. Anything other than those is illegal (and yours starts with FROM for some reason). Put a SELECT and the candidate alias in front of it for more chance of success
Yes Hibernate bastardises the JPQL standard with HQL (which allows you to omit SELECT plus the alias) but you are using OpenJPA so you need to use JPA compliant queries, and besides it would be good practice even when using Hibernate to obey the standard!

Ebean query using setDistinct() does not work

I'm using an ebean query in the play! framework to find a list of records based on a distinct column. It seems like a pretty simple query but the problem is the ebean method setDistinct(true) isn't actually setting the query to distinct.
My query is:
List<Song> allSongs = Song.find.select("artistName").setDistinct(true).findList();
In my results I get duplicate artist names.
From what I've seen I believe this is the correct syntax but I could be wrong. I'd appreciate any help. Thank you.

I just faced the same issue out of the blue and can not figure it out. As hfs said its been fixed in a later version but if you are stuck for a while you can use
findSet()
So in your example use
List<Song> allSongs = Song.find.select("artistName").setDistinct(true).findSet();

According to issue #158: Add support for using setDistinct (by excluding id property from generated sql) on the Ebean bug tracker, the problem is that an ID column is added to the beginning of the select query implicitly. That makes the distinct keyword act on the ID column, which will always be distinct.
This is supposed to be fixed in Ebean 4.1.2.

As an alternative you can use a native SQL query (SqlQuery).
The mechanism is described here:
https://ebean-orm.github.io/apidocs/com/avaje/ebean/SqlQuery.html
This is from the documentation:
public interface SqlQuery
extends Serializable
Query object for performing native SQL queries that return SqlRow's.
Firstly note that you can use your own sql queries with entity beans by using the SqlSelect annotation. This should be your first approach when wanting to use your own SQL queries.
If ORM Mapping is too tight and constraining for your problem then SqlQuery could be a good approach.
The returned SqlRow objects are similar to a LinkedHashMap with some type conversion support added.
// its typically a good idea to use a named query
// and put the sql in the orm.xml instead of in your code
String sql = "select id, name from customer where name like :name and status_code = :status";
SqlQuery sqlQuery = Ebean.createSqlQuery(sql);
sqlQuery.setParameter("name", "Acme%");
sqlQuery.setParameter("status", "ACTIVE");
// execute the query returning a List of MapBean objects
List<SqlRow> list = sqlQuery.findList();

i have a solution for it:-
RawSql rawSql = RawSqlBuilder
.parse("SELECT distinct CASE WHEN PARENT_EQUIPMENT_NUMBER IS NULL THEN EQUIPMENT_NUMBER ELSE PARENT_EQUIPMENT_NUMBER END AS PARENT_EQUIPMENT_NUMBER " +
"FROM TOOLS_DETAILS").create();
Query<ToolsDetail> query = Ebean.find(ToolsDetail.class);
ExpressionList<ToolsDetail> expressionList = query.setRawSql(rawSql).where();//ToolsDetail.find.where();
if (StringUtils.isNotBlank(sortBy)) {
if (StringUtils.isNotBlank(sortMode) && sortMode.equals("descending")) {
expressionList.setOrderBy("LPAD("+sortBy+", 20) "+"desc");
//expressionList.orderBy().asc(sortBy);
}else if (StringUtils.isNotBlank(sortMode) && sortMode.equals("ascending")) {
expressionList.setOrderBy("LPAD("+sortBy+", 20) "+"asc");
// expressionList.orderBy().asc(sortBy);
} else {
expressionList.setOrderBy("LPAD("+sortBy+", 20) "+"desc");
}
}
if (StringUtils.isNotBlank(fullTextSearch)) {
fullTextSearch = fullTextSearch.replaceAll("\\*","%");
expressionList.disjunction()
.ilike("customerSerialNumber", fullTextSearch)
.ilike("organizationalReference", fullTextSearch)
.ilike("costCentre", fullTextSearch)
.ilike("inventoryKey", fullTextSearch)
.ilike("toolType", fullTextSearch);
}
//add filters for date range
String fromContractStartdate = Controller.request().getQueryString("fm_contract_start_date_from");
String toContractStartdate = Controller.request().getQueryString("fm_contract_start_date_to");
String fromContractEndtdate = Controller.request().getQueryString("fm_contract_end_date_from");
String toContractEnddate = Controller.request().getQueryString("fm_contract_end_date_to");
if(StringUtils.isNotBlank(fromContractStartdate) && StringUtils.isNotBlank(toContractStartdate))
{
Date fromSqlStartDate=new Date(AppUtils.convertStringToDate(fromContractStartdate).getTime());
Date toSqlStartDate=new Date(AppUtils.convertStringToDate(toContractStartdate).getTime());
expressionList.between("fmContractStartDate",fromSqlStartDate,toSqlStartDate);
}if(StringUtils.isNotBlank(fromContractEndtdate) && StringUtils.isNotBlank(toContractEnddate))
{
Date fromSqlEndDate=new Date(AppUtils.convertStringToDate(fromContractEndtdate).getTime());
Date toSqlEndDate=new Date(AppUtils.convertStringToDate(toContractEnddate).getTime());
expressionList.between("fmContractEndDate",fromSqlEndDate,toSqlEndDate);
}
PagedList pagedList = ToolsQueryFilter.getFilter().applyFilters(expressionList).findPagedList(pageNo-1, pageSize);
ToolsListCount toolsListCount = new ToolsListCount();
toolsListCount.setList(pagedList.getList());
toolsListCount.setCount(pagedList.getTotalRowCount());
return toolsListCount;

ORMLite or Query across multiple tables

I am trying to query a table based on criteria from a join table using ORMLite.
Here is how I would express the query I am trying to write in tsql:
select * from media m inner join file f on m.fileId = f.fileId
where m.isNew = 1 OR f.isNew = 1
The result should be a list of media records where either the media record or the corresponding file record has isNew = 1.
I have read through the documentation on using OR in ORMLite, but all of the examples use a single table, not joining. Likewise I have read the documentation on joins, but none of the examples include a where clause that spans both tables. Is there any way besides a raw query to do this?
I had a look at this question: https://stackoverflow.com/a/12629645/874782 and it seems to ask the same thing, but the accepted answer produces an AND query, not an OR. Here is my code that I used to test that theory:
public List<Media> getNewMedia() {
Session session = getSession();
Account account = session.getSelectedAccount();
ContentGroup contentGroup = account.getSelectedContentGroup();
List<Media> results = null;
try {
QueryBuilder<Category, Integer> categoryQueryBuilder = getHelper().getCategoryDao().queryBuilder();
categoryQueryBuilder.where().eq("group_id", contentGroup.getId());
QueryBuilder<MediaCategory, Integer> mediaCatQb = getHelper().getMediaCategoryDao().queryBuilder();
mediaCatQb = mediaCatQb.join(categoryQueryBuilder);
QueryBuilder<FileRecord, Integer> fileQueryBuilder = getHelper().getFileDao().queryBuilder();
fileQueryBuilder.where().ge("lastUpdated", contentGroup.getLastDownload());
QueryBuilder<Media, Integer> mediaQb = getHelper().getMediaDao().queryBuilder();
mediaQb.where().eq("seen", false);
// join with the media query
results = mediaQb.join(fileQueryBuilder).join(mediaCatQb).query();
} catch (SQLException e) {
Log.e(TAG, "Sql Exception", e);
}
return results;
}
For the sake of completion, this is querying for a slightly more complex example than the one I gave above, this one expressed in tsql would be
select * from Media m join FileRecord f on m.fileRecordId = f.fileRecordId
where m.seen = false OR f.lastUpdated >= lastUpdateDate
When I run it, it is actually doing an AND query, which is what I would expect based on two joins with independent where clauses.
I think the key issue is that a where clause is inherently tied to a table, because it is performed on a QueryBuilder object which comes from a Dao that is specific to that table. How can I get around this?

I think what you are looking for is joinOr search for it in the ORMLite docs.
Like join(QueryBuilder) but this combines the WHERE statements of two
query builders with a SQL "OR".

How to check if any object is related to a row in a table with constrain of foreign key

I am using Hibernate and MySql.
I have a 2 tables:
User: id, name, type
City: id, name, type
type: id, name
Where user.type has foreign key to user_type.id. and as well city.
I would like before deleting a row in user_type table, to check if any row from any table is related to it.
my columns are mapped for example:
#ManyToOne(fetch = FetchType.EAGER)
#JoinColumn(name = "type_id")
How can I do it?

You said
I have around 100 tables like User and City mapped to this value
ok. Hibernate with JPA book says
You may have removed all other references manually
Which implies you should query manually any related Table. But it says if other entity references Type, database constraints prevent any inconsistency and you see a foreign key constraint exception. I Think it is the best way you can check out what you want. Otherwise, you should query manually for any related Table.
try {
userType = (Type) session.load(Type.class, id);
session.delete(userType);
/**
* or JDBCException
* e.getCause()
* e.getErrorCode() - vendor-specific
*/
} catch (HibernateException e) {
// checkout Exception right here e.getCause();
}
All exceptions thrown by Hibernate are fatal. This means you have to roll back the database transaction and close the current Session. So you may want To open a new session.

use native SQL with Hibernate together:
boolean canDeleteType(ind type_id){
Session s = HibernateUtil.getSessionFactory();
s.beginTransaction();
Query q = s.createQuery("SELECT User.type_id From User");
List l = q.list();
if(l.contains(type_id){
return false;
}
return false;
}
and do the same for your City table too.