I just started with ASP.NET MVC 1.0. I've read through some tutorials but I don't have any good ideas on how to build my model.
I've been experimenting with LINQ to SQL. Can't say I like it that much, but I'll give it a try. I prefer using SQL Stored Procedures, but it doesn't seem to work very good together with the optional parameters in my stored procedures.
The project is a prototype, but I would like to start with a good design right away.
The database will probably contain around 50 tables and stored procedures will be used for all queries and updates. Some procedures will also return multiple results. How would the best way to design this model?
All and any ideas are welcome. Should I even use LINQ to SQL? Should I design my stored procedures to only return one result? I feel a little bit lost.
You can use stored procedures with LINQ. You simply need to replace the autogenerated statements on your entities with your stored procs. Look at the properties for the entity (table) in the designer to change these. Your stored procedures won't be able to return multiple results as they need to map onto a collection of either one of your entities or an autogenerated entity, i.e, onto a collection of a single class.
Having said all that, I'd give it a go without using stored procedures. The LINQ code is fully parameterized so you already have this benefit. You'll find that LINQ allows you to easily build up queries alleviating your need for the optional parameters in your stored procs and, likely, resulting in more efficient queries as you don't need to build extra logic into your query to handle the optional parameters. Once you start using LINQ I think you'll find that the power and expressiveness in the code will make you forget about using your stored procedures.
You may still have a need for stored procs or table-valued functions for complex queries -- that's ok. If they map onto an existing entity, you can simply drag the proc/function onto the entity in the designer and you get a nice method on your data context that runs your SQL and returns collections of that entity. If not, I often create a view for the proc/function schema, use that as an entity, and attach the proc/function to it.
May I ask why you need to use stored procedures for this project? They have almost no value today if you are working with a modern database. Parameterized SQL using a good ORM will give you the same cached execution plans and security benefits that you are looking for with stored procedures.
I would recommend NHibernate because it's a far better way to achieve persistence ignorance. And IMHO this is the goal of anyone designing a model. You should be thinking object first instead of data first.
The best resource around is a screencast series by Steve Bohlen "The summer of nhibernate"
Also LINQ to NHibernate is available and works great for any dynamic query that you might need to write.
The only pain you will notice with NHibernate is the XML, but if you really enjoy the ORM you could write a fluent interface instead using FNH.
I found NHibernate to be the best tool around for modeling a domain because your objects are 100% infrastructure free and this allows you to do anything you want with them without having to worry about the database. Also if you are into unit testing of any kind this will make your life much easier :P
Edit
Part of the reason I replied to your question is that I have built many a system using stored procedures and found to regret that decision later. But in my situation I had a requirement by a dba so I couldn't step away from the norm.
If you are already looking at LINQ to SQL I would simply encourage you to look at NHibernate as another great option to achieve the goal of persistence ignorance.
When I got away from thinking about the problem data first it allowed me to work at a much higher level and take advantage of the .net platform for solving problems. TSQL has its place but if you are writing an application and want to maintain it - try to think about how your domain objects will work together in memory first.
Related
As generic repositories can be use for Insert, Update, Delete etc. but it is limited only for simple Crud operations, if I want to use my generic repositories for some more complex insertion and searching like joining of tables and retrieve by stored procedures. And insert data to multiple tables using stored procedures so how will I handle it from generic repositories?
1. Can I call stored procedures from my generic repository?
2. Is it a good idea to use generic repositories + stored procedures?
3. Will it compatible for criteria base complex search?
Your question should be more specific in order to give you a right answer, but here's my two cents:
Yes it is possible to call stored procedures from your repository. If you are using Entity Framework, it is possible to map stored procedures to a CLR object, which you can call from your repository. Depending on the framework (or lack of it) you use, you'll need to figure out the right syntax to do so.
Personally I wouldn't use this approach as I'd rather put business logic in the business layer. However in some cases it will definitely be useful, for instance when performance is ultra important or where you want complete control over your queries, or some other complex operations.
Do keep in mind that you do can use LINQ to build your complex queries (joining, ordering, filtering, aggregating, selecting,, ..). Some parts can even be automated, like the WHERE clause using PredicateBuilder, enabling you to dynamically create and/or queries based on user input, search criteria,..
In general, YES it is possible but it all depends on the context where you're working in.
We are doing a new project, for all devices and browsers compatibility we have decided to use asp.net mvc 4, Html5, css 3, for communicating with Database Entity Framework we want to use.
Our senior members(Manager, DBA(they are also new to mvc 4, EF)) in the team asking us to write every thing will be in the stored procedures while communicating Database so that maintenance becomes easy.
Is it the correct match if we go like that(MVC4+ EF + stored procedures)? Will i not get maintenance and performance if i go with Code first reverse engineering(because database tables are ready i want to do like that), Please reply.
Below is the flow we want to do, please correct me
As Database is already ready, so first we will write the stored procedures for communication with DB.
New Mvc 4 project and will add .edmx file(EF) and select tables and Stored procedures
in mvc controller or web api we write the consuming stored procedures
There is nothing technically wrong with ASP.NET MVC + EF + Stored Procedures approach, from the first sight.
But my experience show, is that typically it's huge overkill. The common problem I see is the conflicting interests between developers and DBA's. In most worst scenarios all DB releated stuff are controlled by DBA, so if developer what to add/change some feature he needs to wait for implementation of it by DBA (or wait for approve, which could also take long).
So, I personally see that as more bureaucratic way of development.
My own perpective is to be more agile on development and tools like Code First matches that. Stored Procedures could still play major role, while code/performance optimization, but not something to start with.
I agree that using stored procedures in the database is a good approach. Centralizing data validation and calculations in the database ensures data integrity. Client-side validation is important for the user experience but you must also ensure that you test the data validity in the database.
Using Entity Framework, you can generate entities which relate directly to tables in your database, or else you can design entities which use procedures for insert/update/delete operations rather than simple table updates.
In MVC you will use the entities as models to manage your data interactions.
Good luck
This is my personal view. I am sure others might have different ones. Since you are asking this question I am hoping you are open for discussions, otherwise I wouldn’t have bothered as this topic is like a religious discussion as lots of people have very strong opinions and are not likely to change them.
Personally I don't think stored procedures are meant to write business logic. They should be used for writing data access logic. I would only use a stored procedure if I want to optimize an expensive query such as a dynamic search but nothing else. You will get slightly less performance if you have your logic in the domain model, but its not even noticeable in most situations.
One of the strong arguments for writing business logic in stored procedures is because you can easily change some logic by changing your stored procedure. But should we really go and change the business logic of a deployed application without doing proper testing. What will happen if you accidently do a mistake? Doing a deployment is not such a big deal now with continuous builds and I don’t think as a professional developer you should take that risk.
When you decide to write your logic in stored procedures, you give up all the object oriented concepts and you end up writing some procedural code that we wrote maybe 10 years ago. C# language has come a long way now and you will not be able to use those new language features in heart of your application which is business logic. You also loose the visual studio features to refactor code, advanced and easy debugging features etc.
I also don’t like the idea of having triggers as it’s not visible in source code. Imagine someone new in your team trying to add a new feature some time later and if he doesn’t know that a trigger exists, he might write some incorrect logic.
If your application contains some complex business logic, (I am sure most applications do) you should have a domain model that contains not only just properties of your entities, but also your logic. Otherwise you will be falling in to the anti-pattern called anemic data model.
You will not be able to test your business logic by writing unit testing if you have your logic in stored procedures.
You will also not be able to deploy your business logic to multiple servers if you have them in stored procedures if your site becomes really successful.
You will also not be using all powerful capabilities of Entity framework and LINQ if you have all your logic in your stored procedures. You actually don’t need an ORM Mapper if that is the approach you are going to take.
This is what I would recommend for your project.
Even though you already have the database, you can still use code first approach of Entity framework. You can download the EF code first reverse engineer power tool and have the code first code auto generated for you. This is going to be a one off thing and after than if you have any more changes, you can directly do to the database and update the code first code accordingly. Fluent API is bit confusing at first, but you can easily learn that from the generated code.
Do not access your data context from the controller. Have a repository layer that will contain all your data access logic. You can access the repository from your controller. (This allows you to unit test your code by mocking the repository). There are lots of video tutorials on how to use the repository pattern on asp.net site.
Your domain model is going to be the entities that got generated from the Entity framework. Try to have your business logic in those models. It takes a little while to get use to the domain model pattern. But one you get used to it you will start to appreciate its benefits.
Hope this helps.
hi all
We do know that CommandType property of a SqlCommand object has 3 options: TableDirect, Text and StoredProcedure or "SP".
Knowing that "SP" has benefits over two other options, my question is do you make lots of SP in your own systems?
Or What solution do you have instead of creating SP?
Thank you
Aside of creating Stored Procedures you can use Object Relational Mapping
Such as:
linq to sql
Nhibernate
Entity Framework
Data Access :SP's vs ORMs
Choose the best way that suits you.
In all production system I used SPs and pure ADO.NET Core to access the data. Systems range from having 100-300 tables and about 500-1000 stored procedures.
Most of the Data Access code is generated using a tool. I've posted the source code and sample application on my blog if you're interested in using/modifying it. The tool can generate over 100,000 lines of code in about 20-25 seconds going against a database with about 750 stored procedures.
Data Access Layer - Code Gen
Of course if you're no familiar with Databases, data modeling/design and stored procedures you're probably better off using Linq to SQL or EF4 (Entity Framework version 4) or similar. If you need brute force performance then ADO.NET core along with Stored procedures is the way to go.
Re: your first question
When you go down the path of stored procedures, the number of stored procedures begins to grow continually for the life of the project. Outside of the basic CRUD operations, each stored procedure tends to be tightly bound to a particular problem and not very re-usable. A rule of thumb is that I can expect 8-12 stored procedures for each data table (excluding reference or code tables, such as the list of states or countries).
The very large number of procs makes naming conventions very important so that you can find anything without constantly visually re-scanning the whole list of 400-500 procs.
Re: your second question
There are a lot of ugly things that happen with sql written inside of strings inside of C# or VB.NET -- it's error prone, ugly, etc.
Linq, nHybernate and many others exist, but the "concept count" (the number of things you need to learn to start being productive), is much higher than learning how to write a good stored procedure executer in C#.
I try to make sure that stored procedures are only created for database functionality - not business logic.
It's Database Functionality when I have some database architecture that's a bit obscure and I want to hide that from callers.
It's Business Logic when it is simply the way in which my application adds or updates or how much validation they do, etc., etc.
I'm developing a Java EE application (JSF + Richfaces + Oracle 10g), and i wanted to use JPA.
But in the end, i didn't see any advantages of using it, because it's going to complexify my code.
I found that calling my procedures (stored procedures in my orale DB) is better than using JPA (because i can, for example, change some lines in those procedures without the need to re'compile my "WAR" project every time i have some error + i can use PL/SQL which helps me a lot)
So, i wanted to ask you people, when to use JPA ?
Isn't making your own queries (you can choose the right ordering for you selects, the columns that you want to select, and not all the columns: because of ORM and the fact that your entities attributes are mapped to the columns of your table, and that oblige you to select all the attributes present in your entity,....)
Is it my method that i used (stored function)
But in the end, i didn't see any advantages of using it, because it's going to complexify my code.
This might be subjective but, personally, I find JDBC typically more verbose, harder to maintain and thus somehow more complex. With an ORM like JPA, you don't have to write all the CRUD queries, you don't have to handle the mapping of query results to objects, you don't have to handle the low level stuff yourself, etc.
I found that calling my procedures (stored procedures in my orale DB) is better than using JPA (because i can, for example, change some lines in those procedures without the need to re'compile my "WAR" project every time i have some error + I can use PL/SQL which helps me a lot)
This is totally dependent on your definition of "better". In your case, you might prefer SP because of your development workflow (I don't run my code in container to setup the persistence part) and because you are comfortable with PL/SQL. But again, personally, I don't find SP "better":
I don't really enjoy hand writing SQL queries for everything
I find that SP are harder to test, debug, maintain
I find that SP are bad for code reuse
I find that SP lock you in (I consider this as a disadvantage)
I tend to find systems build around SP harder to scale
Read also Who Needs Stored Procedures, Anyways? (amongst other resource) for more opinions.
So, I wanted to ask you people, when to use JPA ?
When you want to speed-up development, to focus on implementing business code instead of plumbing. And of course, when appropriate.
Isn't making your own queries (...)
Did you identify a particular performance problem? Or are you just assuming there will be a problem. To my experience, retrieving more columns than required is most of time not an issue. And if it becomes an issue, there are solutions.
You can define what fields are retrieved in a query, using JPA.
Why is the complexity of your code going up with use of JPA ? You state no example. Before you'd have to do messy JDBC, and now you just call "em.persist(obj)" ... is that really more complex.
You ought to be thinking in terms of what relations there are between objects (if any) and that be the determiner on whether you need an ORM
If I use stored procedures, can I use an ORM?
EDIT:
If I can use a ORM, doesn't that defeat part of the database agnosticity reason for using an ORM? In other words, why else would I want to use an ORM, if I am binding myself to a particular database with stored procedures (or is that assumption wrong)?
Using ORM to access stored procedures is one of the best uses of ORM. It'll give you strongly typed objects, while you still have full control over the SQL.
In my experience I would let the ORM handle the 'CRUD' operations, and leave the specialty work to the stored procedures. Generally, using a stored procedure for 'CRUD' operations is overkill, and to let the ORM handle it, could drastically improve your productivity.
Yes, you can, all main ORMs support stored procedures.
As for your assumption, you are particulary right, when you use stored procedures with ORM you are coupling your project to a particular database. But in practice it is 99% that you will not need to change your database provider, so in this case you use ORM not to abstract from concrete DB provider, but to help yourself with object-relational mapping task - which is a main ORM's task and which ORM was originally made for.
It raises an interesting point.
Once you have ORM, and relatively simple queries, why do you need stored procedures? SP's are intimately bound to the database. ORM frees you from having to maintain a lot of DB-specific code. What is DB-specific can be isolated and managed.
I suggest that an ORM is a golden chance to cut the complexity and put all the processing in the code where it belongs.
Use the database for what it does best -- store data.
Use your application for what it does best -- process data.
You can use both ORM features and stored procedures functionality at once. Particularly use ORM until it fits you, but if you have some trouble with performance or need some low level tune - include stored procedures in your business-logic.
Yes you can but you will want to spend some time investigating what capabilities the ORM provides around stored procedures.
Most will allow you to run a stored procedure that returns a strongly typed object / entity. More advanced ORM's will allow you to plug stored procedures in for performing CRUD actions as well (so your generic querying, deleting etc goes via a stored procedure rather than a dynamic query).
Generally ORM's are great for generating ad-hoc queries and getting strongly typed entities but having strong stored procedure support has the benefit of allowing you to (sometimes) more easily access native capability of your RDMS that may not be exposed as first class citizens in the ORM - especially if the ORM supports many database engines.
Following up from your edit:
Often you will want to use the ad-hoc querying engine provided by the ORM however as I alluded to earlier - sometimes you want to query using a capability not exposed from the ORM.
The benefits of strongly typed entities is invaluable as it means you have domain object usually, rather than data readers, data tables etc. You can cleanly encapsulate behaviors and logic within those entities that you have retrieved.
The list of additional benefits is very long indeed - for example, with the LightSpeed ORM (and most others) your entities will support standard binding interfaces, error reporting interfaces, validation etc. On the querying side you will lose out on lazy loading etc unless you write it yourself.
Database "agnosticity" (?) is not the only reason to use an ORM. However, you could take advantage of being DB independent on 99% of your interactions with the DB and in 1% (or 2% or 10% or whatever) you might need stored procedures for speed/clarity/complexity. If you changed DBs, you would need to rewrite those.
I use netTiers a lot at work and we let it generate our stored procedures for us. These only handle the basic CRUD operations, but they are very fast and save me a TON of time. netTiers will also let us create custom stored procedures and generate our data access code with these procedures.
You can, but many of the more advanced ORM features tend to become more cumbersome to use. Something like iBatis is very easy to integrate with stored procedures, while the more sophisticated features of more complex engines like (N?)Hibernate like generation of dynamic SQL and lazy loading of large fields can become more of a hassle than they're worth.
I believe that any tool that frees you from redoing work and concentrate in solving the problems is valid. ORMs appear to be that tool when it come to basic CRUD operations - even if using SPs to better implement a requirement (like using a hammer on a nail, it's just the right tool for task).
The point is: there's no black or white, just a scale of gray. Very inneficient and badly coded applications use the excuse of being 'DB agnostic' to explain the exagerated use of DB resources. In many cases, being very tied to a database is not good too. The objective is: getting maximum 'DB agnosticism' while not wasting customer IT resources without need.
There's no 'old vs new', just people saying that extreme 'pure' approaches are better. I don't really believe so. I believe that, as with any tool, the 'best' (notice the quotes) approach is using ORM until still is the right tool to make your data access. And use SPs inside your ORM when you reach a point where you're wasting resources and reducing scalability and 'worth life' (I forgot the english expression equivalent for the portuguese 'vida útil') of TI resources. Or, in other words, use SP when it's for the processing at hand what a hammer is for the nail.