How can I use the tools to generate DAOs?
In fact, instead of passing through the hbm files, I need to configure hibernate tools to generate the DAO and the annotations.
See Hibernate Tools - DAO generation and How generate DAO with Hibernate Tools in Eclipse?
First let me assume DAO as POJO/Entity beans. Basically you can accomplish your task either through forward or reverse engineering. In case of forward engineering, probably you can look into AndroMDA tool. In case If u wish to accomplish it through reverse engineering Click here ..
Hope this will be helpful.
Welcome. You got to write all your data access logic by your hand (if I’m not wrong). Hiberante let you interact with database in three ways.
Native SQL which is nothing but DDL/plain SQL query. This can be used very rarely in hibernate projects even though this is faster than below mentioned options. Reason is simple “One of the key advantage of hibernate or any other popular ORM framework over JDBC Is you can get rid of database specific queries from your application code!”
HQL stands for hibernate query language which is proprietary query language of hibernate. This looks similar to native SQL queries but the key difference is object/class name will be used instead of table name and public variable names will be used instead of column names. This is more Object oriented approach. Some interesting things will be happening in background and check if you are keen!
Criteria API is a more object oriented and elegant alternative to Hibernate Query Language (HQL). It’s always a good solution to an application which has many optional search criteria.
You can find lots of examples on internet. Please post your specific requirements for further clarification on your problem.
Cheers!
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I want to process a batch file into some Sql table and I'm thinking of using Data Transformation for it has the mapping funcionality which is very good. Is there any way to define a Target Type that can be helpful for this task?
If we go with Camel (which has several database-capable components) we will get a graphical depiction of the application flow through basic Fuse Tooling. (There is no graphical mapper, though.)
I hope that helps. Camel really does make it easy to handle your messages and put them in a database-- but you can't drag-n-drop that part of the application design.
Rick
You can use the mapper if you want, but you might also give consideration to using Camel for this task.
Camel offers JPA, Hibernate, JDBC, SQL etc. all good ways to send data to a database. Camel's got great flat-file handling skills, too, so it's a pretty easy task to set things up for the persistence part.
In my spare time, I'm trying restart my effort to learn F#. I'm doing so by trying to create a simple application that will allow me to analyze my financial transactions.
My first attempt at creating this application failed due to the persistence step. I used SQL and the EntityFramework package, but the latter generated database entities, which I did not want to use throughout my application since they're all mutable (I think..). Instead I had to map these database entities to domain entities. Much manual glue code later it worked....until I found a bug and was forced to replace much of that glue code. That was the tipping point that made me quit.
On SO I found a question describing my situation, e.g. Saving F# types to a database. Mark Seeman suggested that the pain of mapping can be overcome if I'd not use objects for persistence. At work I have recently been introduced to MongoDb, which at least saves me the pain of mapping from database entities to domain entities. These entities all need some ID, and I chose to use an ObjectId from Mongo. Ooops, there comes the deja vu, in order not to have my domain entities being dependent on Mongo, I will once more have to create database and domain entities....as well as the mapping. Bah & Ugh.
In C# I'm used to do such mapping with tools like Automapper, but they don't really work for special F# types. So now I'm wondering what Mark Seeman ment by "using objects for persistance". How is this solved in F#? So far I haven't been able to fine more info on this topic besides the aforementioned question on SO.
I have written a wrapper around ADO.NET's DbProviderFactory that I use extensively throughout my applications. I also have written a lot of code that maps IDataReader rows to POCOs. However, as I have tons of classes the whole thing is getting to be a pain in the ass to maintain.
I have been looking at replacing the whole she-bang with a micro-orm like Petapoco. I have a few queries though:
I have lots of POCOs that contain other POCOs in them as properties. How well does the Petapoco support this?
Should I use a ORM like Massive or Simple.Data that returns a dynamic object and map that to a POCO?
Are there any approaches I can take to the whole mapping of rows to POCOs? I can't really use convention-based tools as my database isn't particularly consistent in how it is designed.
How about using a text templating/code generator to build out a lightweight persistence layer? I have a battle-hardened open source project called TextMetal to generate the necessary persistence layer based on tried and true architectural decisions. The only lacking thing is object to object relations but it does support query expressions and works well with poorly designed data schemas.
You can see a real world project that uses the above tool call Can Do It For.
Feel free to ask me about any design decisions once you take a look-sse.
Simple.Data automagically casts its dynamic type to static types. It will map nested properties as long as they have been eager-loaded using the .With method. So for example
Customer customer = db.Customer.WithOrders().Get(42);
would populate the Orders property of the customer object.
Could you use QueryFirst, or modify it? It takes your sql and wraps it in vanilla ADO code, generated at design time. You get fresh POCOs from your result schema every time you save your file. Additionally, you can choose to test all queries and regenerate all wrappers via the option in the tools menu. It's dependent on Sql Server and SqlClient, so unless you do some modification, you'll lose DbProviderFactory.
I have a postgres database and I want to generate the entity class of a table. I need this in order to connect to the database without using something like :
NpgsqlCommand cmd = new NpgsqlCommand("SELECT * FROM TABLE1", conn);
How can I obtain the class?
Can you provide some detailed steps? I can't seem to find this anywhere.
Thanks in advance!
Entity classes are usually hand-written, or are generated from a schema then hand-tweaked. In the Java world many tools like NetBeans and Eclipse can help, but things seem much less mature in the C#/.NET world if you're not using Microsoft databases and Microsoft query tools.
This answer refers to a few useful tools, and a quick search also found the NHibernate entity generator, which seems to be part of a tool with support for Entity Framework and LINQ too.
Depends on a language but yes - you can do something like this in Java or Python using Object Relational tools such as SQLAlchemy, Hybernate, iBatis, etc.
They can generate schema for you, can populate data based on the definitions of objects.
I have now decided to try out ASP.NET MVC 3.
My host provider, however, only supports MySQL and therefore I have to figure out how to use MVC 3 with MySQL.
I have also decided that I don't wanna do any SQL code if I can avoid it, and I would also like O/RM without too much effort. I understand that the Entity Framework will actually help me accomplish this to a large extent.
I have been trying to get into the various ways of using the EF, with the database first, model first and code first approaches supplied by the framework.
So far, I have not had much luck, and I find that the examples available all use very different approaches that confuses me a lot.
I might begin by asking for guidance on getting a few concepts right.
First of all, the Model (in MVC) is actually more like a ViewModel, that represents something (Users, Posts, etc.) in terms of Properties is more or less simple classes. I.e. the model is where the data from the database gets mapped to an object (the O/RM). Am I right?
A repository is a wrapper that encapsulates a specific way of retrieving data for the models. For instance, a DatabaseRepository or a FakeTestRepository.
Should I have a single repository in my MVC project, or a repository per database table, such that I have a UsersRepository and PostsRepository?
Should the repository be a model for itself, not a model at all, or tied to individual models (so that UsersRepository is part of the UsersModel)?
I have tried to use the EF's model first approach, and for a simple test I just have created an empty model and added the entities "Author" and "Guide" that are related by a one-to-many relation.
When I then, in Visual Studio 2010, "Generate database from model", I get the corresponding sql code. I want this database to be created in MySQL. How can I accomplish that?
Are there some code examples for MVC 3 with MySQL and O/RM where the creation of a small site is demonstrated?
Thanks.
Concerning EF Model First approach: take a look at this Tips & Tricks article. We have described this common situation in it (it is Oracle-specific, but dotConnect for MySQL contains the "Devart SSDLToMySQL.tt" template).
As for the rest of the questions - there is no definite answer. Choose the approach that suits you better.
In my point of view, you should try the code first. And as you said that your host only provides MySQL you can also use MySQL database as a database I personally use MySQL. Concepts are the same but logic is different you have to code it a different way. But from my point of view, you can use MySQL as a database service.