Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 9 years ago.
Improve this question
In the last time I heard a lot of complaining about Hibernate. And indeed I have some painful experiences with Hibernate too. So I read about Ebean and Siena.
Both have interesting approaches. Unfortunately, database access layers are very easy to write, but if your project grows and you have to handle great database-tables, you know if they are good or not. So it's really difficult to evaluate such a tool. Hibernate is well known and you could be sure that you can solve your problem with it. Sometime you need to learn a lot, but you can solve it.
How is it with Ebean? Are there any real world applications? Which databases are supported? Is it reliable?
After searching a little bit more I see that there are a lot more ORM-frameworks, so is there at least one reliable one?
Rob (Ebean Committer) here.
Ebean is about 4+ years old now. I would say it is fairly mature now. The supported DB's include Oracle, MySql, Postgres, H2 and SQL Server (and recently SQLite). Ebean is doing stuff that other ORM's are not such as Autofetch (automatic query tuning) so I'm not how that fit's into a 'maturity rating'. IMO the Ebean community is relatively small though so you probably need to hit the Ebean google group to engage them.
Any real world applications? Yes, but you are best to ask the Ebean community about that really. Certainly there is good support for batch processing (batch size, turn of cascading persist for a transaction etc) and large query support that I don't see in JPA etc (you might get something similar with Hibernate's Sessionless support).
Hopefully this might answer some small parts of your question anyway.
Cheers, Rob.
I'm currently a developer of Siena but not since very long. Let me explain why I became a developer on this project?
I went to Siena because I wanted to use Play+GAE and Siena appeared to be a good start for GAE DB and I really wanted to avoid JDO/JPA.
Then, I began to really appreciate Siena for its straightforward, light and easy approach and so simple APIs. It doesn't pretend to be the all-in-one abstraction layer like JDO and the greatest standard DB API like JPA. It really made me think of DB APIs from Python/Ruby and it really fits my point of view: I want a simple DB API which allows me to solve the great majority of my problems and when I have a more complex problem, I will use the lower layer APIs but certainly not an abstraction layer such as hibernate.
The possibility to make my code work on GAE DB or JDBC was also a good aspect. Once again, Siena doesn't pretend to provide exactly the same things in both worlds because SQL and NoSQL are not really compatible (but ORM is neither really compliant to SQL model :) ).
But once again, it is quite practical to be able to rely on the same APIs in several DBs.
Finally, the library is ONE jar and you don't have to retrieve the whole universe to use it.
So, I became progressively a committer on Siena because I wanted to take part of this nice little adventure.
Now siena team is working on a new version keeping the same simple APIs, bringing new interesting features and really improving all the backend code to make it even easier to extend for new DB support.
Siena is a pragmatic API driven by user experiences and that's why I like it ;)
Pascal
We've had really great experience with MyBatis, which is not an ORM per se, but another class of persistence manager, an SQL Mapper. Using it you start with SQL statements and direct it on how to map result rows into POJOs. It's conceptually easy to understand and tune with not much magic going on inside. It's ideal if you are comfortable with SQL or need to work with an established schema.
Besides Ebean and Siena:
You can try JIRM which is focused on CRUDing immutable objects (yes I'm the author).
There is also jOOQ and Joist.
I feel that JIRM minimizes the number of DTO's because the domain objects are immutable and do not inherit, implement and/or are not "enhanced/instrumented". Such is not the same with Siena and Ebean.
Also because the objects are Immutable there is more of a focus on per column updating instead of the whole object which makes more sense given today's AJAX interfaces (compared to the old POST the whole bean model).
What about using EB3, with for instance JBoss (www.jboss.org)?
Related
I've got involved in a project with entity manager in it. It's a bit unclear why should one use it. We have databases to store information in if we don't we can use classes to store informations in without the entity manager. The question is is it worth the effort to learn? Is it a widely used tool?
I know it's a bit opinion based but I'm interested in the facts mainly. But usually others experience shows how good a tool is.
Yes, JPA and Hibernate are widely used. Their benefits are the speed of the development (especially on the early stages of the project), but since it's a very complicated technology not everyone gets to use it effectively.
Ultimately knowing JDBC and databases is much more important than knowing ORMs. Mostly because everything else related to DBs in Java (including ORMs) is based on JDBC. But also if you need to write a very performant code - JDBC could be the right level of abstraction for you.
If you want to learn ORMs I'd advise to start with the book POJOs In Action - it explains the fundamental principles behind these frameworks. And after that check out Java Persistence with Hibernate - this one is more technically involved and describes all sorts of features in Hibernate.
Apart from the fully-featured ORMs there are lighter technologies that ease up the low-level JDBC burden: jOOQ, Spring JDBC, MyBatis.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed last month.
Improve this question
I am using Java language.I have to use ORM framework with MongoDb as Database.I have two options Morphia or Spring Data Mongo support.As far i am able to get details , it has been found Spring Data Mongo is better to use since:
1)It provides better DAO out of box inbuilt classes.
2)It has larger community base.
Are there any performance based differences between the two.And if there which one is better in which condition.Also i have requirement of multitenancy .After little search i found that there is very simple custom implementation in Spring Data Mongo to do the same.But in Morphia it is somewhat difficult.Does achieving multitenancy in Morphia diificult(where we need to write a lot of boiler plate code)
I have been using Spring-data and I guess I feel somehow it lags as far as maturity is concerned.
It's good for all the practical purposes but the features mongo provides in it's full glory, Spring-data is slow to map that as a driver specially when it comes to aggregation.
As far as performance goes, Spring-data doesn't lag imo.
Sometime I get weird behaviors. Some of their annotation silently doesn't work at some places and for my life I cannot figure out why?
But as an overall implementation it's quite helpful in the way that it provides a robust structure on which your application can grow. It also is easy if you are coming from SQL background since you can draw a parallel between jdbcTemplate and mongoTemplate (though one needs to be cautious)
I seriously considered using Morphia, but dropped the idea since spring-data was providing a more structured ways. Looks like in Morphia we would have to implement some structure on our own which has pros and cons but You usually want to avoid doing it. Since there is a risk of boiler-plate codes, there is a learning curve for 'your' structure for new members.
On the pros side, I am sure Morphia provides more extensiblity leading you to enjoy the ability to suck most out of mongo features. It also is lightweight compared to Spring data.
Morphia is the way to go. Pretty stable, very good Play integration and offers access to all Mongo driver features if you need more torque. Reference resolution, entity embedding are working as expected. You get lifecycle annotations too, which are pretty useful for boilerplate persistence code.
I personally like spring-data because of the hades project... You don't need to implement the DAOs. You just write the interface and spring data automatically provides it to you. However Spring Data Mongodb implementation seems a little buggy in my initial trial. If you have hard dates and is working on a production quality product, probably it is wise to choose Morphia.
Closed. This question needs to be more focused. It is not currently accepting answers.
Want to improve this question? Update the question so it focuses on one problem only by editing this post.
Closed 7 years ago.
Improve this question
I'm a little bit confused on how the process of developping a database based application.
I'm using java language and Relational database.
What's the correct way of looping through the process of developping Object Oriented database based application like "inventory management control".
Developping database schema then doing OOD or Vice versa.
Since I assume you are about to use a traditional RDBMS, from my own experience, it'll be best to first design the database schema: think of all the tables you need to store your information, think of the relations between them (foreign keys).
The next step should be writing the application itself. I assume you're about to use Java, and can benefit from OOP design.
In such a case I strongly recommend using an ORM technology, like Hibernate, to fulfil the gasp between your OOP app design and RDBMS design. Though it's not obligated, since you can use simple JDBC approach.
From my experience, developing this way is much less time consuming than first design your high level OOP application, and then trying to fit a DB schema to it, because usually messing with DB is more time-expensive than with high level OOP abstraction.
There are a number of different approaches possible and they each have their merits and downside.
If you follow the ORM approach and use a tool like Hibernate you can hide much of the database implementation. You would proceed with your OOD and the database schema would drop out of that. ORMs like Hibernate even do the schema generation for you (this is very helpful in testing as you can create an in-memory database on the fly for your tests).
The advantages of this approach is that you can focus on the OOD and work with 'thin slices' where the database schema is generated as you progress. This fits in well with the agile approach.
The downside with the ORM approach is that it may not result in an optimised database schema. For example, the performance of your database schema may not be as good as if you had focused more on the schema design.
If you decide to focus on the database design you can spend time optimising it for performance and other non-functional requirements (like scalability and auditing). The downside with this approach is that it may restrict the way you do OOD in your code and it may be more difficult to work in the iterative fashion preferred by agile.
Closed. This question is opinion-based. It is not currently accepting answers.
Want to improve this question? Update the question so it can be answered with facts and citations by editing this post.
Closed 9 years ago.
Improve this question
Some years ago I started "studying" and working with JAVA (I gotta say that I am an embedded developer, so I mostly work in C and C++).
Receptly I have started working with Databases so I stumbled on Hibernate. I read couple of starting guides and books about the topic and started to play around with some small projects.
Surfing on the Internet (Stackoverflow included) I only have seen projects that include Hibernate/JPA + Spring [+ Struts].
I am designing a quite big personal project. I wanted to do it "step by step" in order to learn all parts that it implies: DB, Hibernate (I wanted to use first hbm.xml and then Annotations), make an easy standalone swing application, and then use Spring + web page.
Probably my question is a little stupid but, I will ask it anyway
Does Hibernate make sense without Spring?
Should I keep playing a little longer with Hibernate while I read up on Spring and then develope the project using both technologies?
My only goal in this project is to learn. Nothing more, nothing less. I do not care about the effort.
Thanks so much for your opinions! I appreciate!
Yes Hibernate make sense without Spring but it will make more sense with Spring :)
As you have already studied Hibernate, you know about it so let me tell you that Spring will make your life more easier mainly because of DI and it also have Hibernate support classes for doing common functions, transaction management.
I suggest you to do both together because without Spring you will be learning obsolete Hibernate Design, for example using Service Locator etc.
Note : You will find learning Spring way much easier as compared to Hibernate :)
Unless you have a pressing reason to do your database work first, I would suggest taking a different approach and learning Spring core before you dive into Hibernate. This is what I did way back when I learned both, and it was very effective for me.
As another answer mentions, Spring is (probably) easier to learn than Hibernate, and you will probably end up with a "cleaner" project as a result of using Spring since using the framework encourages the use of a lot of best practices in Java. Since you're learning Java, that's a big plus.
Once you get those practices down, you can move into Spring/Hibernate integration and tackle that, but you'll probably find it a lot easier.
Closed. This question does not meet Stack Overflow guidelines. It is not currently accepting answers.
We don’t allow questions seeking recommendations for books, tools, software libraries, and more. You can edit the question so it can be answered with facts and citations.
Closed 7 years ago.
Improve this question
I currently have an application, where it's primary performance issue is using file-based database consisted of JSON responses.
I'd like to rewrite my application to use SQLite database feature.
Since I'm lazy, I'd like to use some kind of ORM.
So far I have found only two big ORM libraries:
ORMLite
GreenDAO ORM
DB4O
ActiveAndroid
My primary goal is to raise performance on working with data as much as possible
But I've found two possible issues with those libraries.
ORMLite uses annotations, which is big performance issue in pre-honeycomb due to this bug
GreenDAO is using some kind of code generator, and that would slow me down on development as I would have to write generator, and then use generated code. And I don't very like this idea.
DB4O is JPA, which I've always considered as slow and heavy on memory usage, therefore unsuitable for low-end devices (remember the Android API v7)
ad #ChenKinnrot:
The estimated load should be sufficient to think about using an ORM.
In my case it is about 25-30 unique tables, and at least 10 table joins (2 - 4 tables at a time). About 300-500 unique fields (columns)
So my questions are:
Should I use ORM/JPA layer in Android application?
If so, what library would you recommend me to use? (and please add some arguments too)
I've used ORMLite and found it straightforward once you got the hang of it (a few hours), quite powerful and didn't cause any performance problems (app tested in Gingerbread on HTC desire and HTC Hero).
I will be using it again in any projects I need to use a DB for.
A ORM layer is appealing.
However, in practice I either write simple ORM myself or use the Content Provider paradigm, which does not cooperate well with ORM.
I have looked into some existing ORM libraries (mainly ORMLite ,activeAnroid) but they all scared me away
as they seems not so easy to get started.
"We're talking about 25-30 unique tables, and at least 10 table joins.
About 300-500 unique fields (columns)"
If you have fixed and limited patterns of how the data will be queried, I would recommend to write the ORM/sql yourself.
My 2 cents.
If you are worried about your app's performance, I'd recommend greenDAO. It will save you from writing lots of boring code, so code generation should not be an issue. In return, it will generate also entities and DB unit tests for you.
I got some knowledge to share so:
ORM by definition is slower than writing your own sql, it's suppose to simplify the coding of data access, and provide a generic solution, generic = runs slower than you write your queries, if you know sql well.
The real question is how good performance you want to get, if it's the best possible, don't consider any data mapping framework, only sql generation framework that will help you write stuff faster, but gives you full control of everything.
If you don't want to get the most out of the sql db, use orm, I got no experience with this orm you mentioned, so I can't say what to choose.
And your DB is not so big and complex so the time you'll save with orm is not an issue.
In my experience, I had a lot of benefits from using ORM engines. However, there was the case when I had to deal with performance problems.
I had to load about 10 000 rows from the database, and with a standard implementation (I was using ORMLite), it took about 1 minute to complete (depends on the device CPU).
When you need to read a lot of data from the database, you can execute plain SQL and parse the results yourself (in my case, I only needed to query for 3 columns from the table). ORMLite also allows you to retrieve raw-results. By this, the performance has increased by 10 times. All 10 000 rows were loaded in 5 seconds or less!