ORMLite or Query across multiple tables - java

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".

Related

Cassandra Java driver Performance : CQL Queries with IN Clause having high no of values

We are using Datastax Cassandra java driver (version 3.x). There is a logged batch Select statement with 'IN' clause, having a high number of values. Due to which we are facing a serious issue of low performance. Following is the format of query visible while debugging the Java application:
SELECT COL1, COL2, ... FROM XXXX WHERE PARTITIONKEY IN () AND CLUSTERINGKEY IN();
Can anyone please share how such SELECT with more than one IN clause shall be handled when there is high number of values available to pass inside it.
Does Session#executeAsync can solve this issue.
Thanks.
Don't use IN query for partition key (For a limited number of fixed data you can use if performance is not an issue). It imposes a lot of work to Coordinator node. You can use IN for clustering key but make sure your list is not too large as well.
executeAsync is the best approach here. I am adding a code snippet here.
PreparedStatement getInfo = session.prepare("SELECT COL1, COL2, ... FROM XXXX WHERE PARTITIONKEY = ?");
List<ResultSetFuture> futures = new ArrayList<>();
for (Object key : list) {
ResultSetFuture future = session.executeAsync(getInfo(key));
futures.add(future);
}
for (ResultSetFuture future : futures) {
try {
ResultSet rs = future.getUninterruptibly();
Row rw = rs.one();
if (rw != null) {
// set DB info into list or DTO
}
} catch (Exception e) {
// print log
LOGGER.error("", e);
}
}
It's a sample code. Please read this link for more details:
Cassandra Query Patterns: Not using the “in” query for multiple partitions.

How to use net.java.ao.Query to query issues?

I have this select in PostgreSQL:
SELECT "field_1", "field_2","field_3", MIN(COALESCE(NULLIF("field_4",'') ,'TBD')) MINDP,MIN("field_5") MINBOD FROM "MY_TABLE" GROUP BY "field_1", "field_2","field_3"
And I want to use net.java.ao.Query to query my database. My function:
import net.java.ao.Query;
public List<myClass> find() {
String SQL = "SELECT \"field_1\", \"field_2\",\"field_3\", MIN(COALESCE(NULLIF(\"field_4\",'') ,'TBD')) MINDP,MIN(\"field_5\") MINBOD FROM \"MY_TABLE\" GROUP BY \"field_1\", \"field_2\",\"field_3\""
return newArrayList(ao.find(myClass.class, Query.select(SQL)));
}
The problem is: this code return all issues of my table.
When I run this SQL in postgreSQL console it works fine.
My code has different results than SQL console.
Does anybody know why is this happening?
Old question but if somebody steps over this -
Query.select() is not meant to put plain SQL into. It is more of a builder to create 'database independant' query. See some examples here: Finding entities
public MyEntity[] findMyEntities(String fieldValue) {
final Query query = Query.select()
.where("FIELD_VALUE = ?", fieldValue);
// evaluates to something like this
// SELECT * FROM MY_ENTITY WHERE FIELD_VALUE = x;
return ao.find(MyEntity.class, query);
}
This is why there's another method (which you used in your comment), that can handle plain SQL (findWithSQL).
Attention Query and find() often do not work as expected, so you might not get your original query to work using the query builder.

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;

criteria query ORDER BY yields error. Is this an SQL-SERVER limitation? How could I order by correctly on a complicated criteria query?

I have the following criteria query:
String cat = "H";
Criteria criteria = currentSession().createCriteria(this.getPersistentClass()).
add(Restrictions.ne("category", cat)).
createAlias("employees", "emp").
createAlias("emp.company", "company");
Disjunction disjunction = Restrictions.disjunction();
for(Region r: regions){
disjunction.add(Restrictions.eq("company.region", r));
}
criteria.add(disjunction);
if(status != null) {
criteria.add(Restrictions.eq("status", status));
}
if (period != null) {
criteria.add(Restrictions.eq("period", period));
}
criteria.setProjection(Projections.groupProperty("id")) //this line was added to try to "fix" the error, but it still happened.
criteria.addOrder(Order.asc("id"));
I guess a query that explains my criteria query could be:
select n.* from NOMINATION n
join NOMINEE i on n.NOM_ID = i.NOM_ID
join EMPLOYEE e on e.EMP_ID = i.EMP_ID
join COMPANY c on c.COMPANY_CODE = e.COMPANY_CODE
where n.CATEGORY_CODE!='H' and (c.REGION_ID = ? or c.REGION_ID = ? or c.REGION_ID = ?) and n.STATUS_ID = ? and n.PERIOD_ID = ?
order by n.NOM_ID
What I am trying to do here, is pretty confusing but for the most part it works except when I add this specific line (though the query works fine):
criteria.addOrder(Order.asc("id"));
and then I get error:
java.sql.SQLException: Column "NOMINATION.NOM_ID" is invalid in the ORDER BY clause because it is not contained in either an aggregate function or the GROUP BY clause.
Which I suspect is something that has to do with SQL-SERVER. I am already grouping by id. So what am I doing wrong here, or should I just use HQL?
Your current query seems to be a simple Query which doesn't have any group function used or not a group by query. According to your current requirements you do not have to use this line.
criteria.setProjection(Projections.groupProperty("id")).addOrder(Order.asc("id"));
Or you have to modify your sql statements.

hibernate java select queries

i am new to this and today i tried to play hibernate with a method that returns the result of selected row...if is selected then it can return the result in int.. here is my method
public int validateSub(String slave, String source, String table){
Session session = HibernateUtil.getSessionFactory().openSession();
session.beginTransaction();
Query q = session.createQuery("from Subscribers where slave = :slave AND source = :source AND tbl = :tbl");
q.setParameter("slave", slave);
q.setParameter("source", source);
q.setParameter("tbl", table);
int result = q.executeUpdate();
return result;
}
from this method i tried to validate the 3 values that i get from the Subscribers table but at the end i tried to compile having this error
Exception in thread "Thread-0" org.hibernate.hql.QueryExecutionRequestException: Not supported for select queries [from com.datadistributor.main.Subscribers where slave = :slave AND source = :source AND tbl = :tbl]
You can have a look at the below links that how executeUpdate works, one is from the hibernate docs and other the java docs for JPA which defines when the exception is thrown by the method
http://docs.oracle.com/javaee/6/api/javax/persistence/Query.html#executeUpdate()
https://docs.jboss.org/hibernate/orm/3.2/api/org/hibernate/Query.html#executeUpdate()
Alternatively you can use
List list = query.list();
int count = list != null ? list.size() : 0;
return count;
you are running a select query, Eventhough you are not using the select keyword here hibernate will add that as part of the generated SQL.
what you need to do to avoid the exception is the say
q.list();
now, this will return a List (here is the documentation).
if you are trying to get the size of the elements you can say
Query q = session.createQuery("select count(s) from Subscribers s where slave = :slave AND source = :source AND tbl = :tbl");
Long countOfRecords = (Long)q.list().get(0);
you can execute update statements as well in HQL, it follows a similar structure as SQL (except with object and properties).
Hope this helps.
here you want to select record so it is posible without select key word
sessionFactory sesionfatory;
ArrayList list = (ArrayList)sessionfactory.getCurruntSession().find(from table where name LIKE "xyz");
long size = list.get(0);
I also happened to make the same mistake today.
Your SQL statement is not correct.
You can try:
DELETE from Subscribers WHERE slave = :slave AND source
Try this:
int result = q.list().size();

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