AcroDB. How to use | Less pain in your's development hands

Hi, all! Almost a week have passed, after I have posted my new flexible provider article. Maybe, nobody commented it, because of article compicity... So, today I will try to show you, how to use AcroDb.

The model

Usually, when you start to design your future application, you need to describe 3 levels of MVC, and first of it goes the model layer. For the simple projects, the model layer consists of simple tables/entities. Let's say we have to build a model for only one entity type, to store cars.

Car entity description

What fields should this entity have? Let them be:

ID - the unique Guid of car record (primary key).
Name - car name string (if we need to specify the limit of this field, let it be maximum 80 chars).
YearOfAssembly - the year, when this car starts to drive (integer value).
Description - the text with notes about the car (infinite string).

Car entity prototype in AcroDb

Now let me describe, how this entity will look like in code using AcroDb library.

	[AcroDbEntity]
	public interface ICar
	{
	Guid ID { get; set; }
	[AcroColumnStringLength(80)]
	string Name { get; set; }
	int YearOfAssembly { get; set; }
	[AcroColumnStringLong]
	string Description { get; set; }
	}

view raw 01.cs hosted with ❤ by GitHub

And if you have setup AcroDataContext class settings correctly as it was described in first post, after application start you will have a Car table in your database/no-relational system. Or if you will change properties of this interface, table schema will be updated, thanks to SubSonic.

So, AcroColumnStringLength attribute is used to specify the maximum length of the column in db. The AcroColumnStringLong attribute marks te column as infinite (MAX) size. For all column attributes, please, read here.

Working with entity

Now I will show the parts of code, how to work with our entity.

Creating and saving an object

	using (var manager = AcroDataContext.Go)
	{
	//Object creation and filling
	var car = manager.Provide<ICar>().Create();
	car.Name = "Mitsubisi Lancer";
	car.YearOfAssembly = 2009;
	car.Description = "Mitsubisi Lancer, a bit new, but red one";

	//Saving an entity
	manager.Provide<ICar>().Save(car);
	//Don't forget to submit changes
	manager.SubmitChanges();
	}

view raw 02.cs hosted with ❤ by GitHub

Querying a db

Here is a sample of Linq query for multiply objects:

	using (var manager = AcroDataContext.Go)
	{
	//We will find all cars assembled in 2009 and will show it to console
	var collection = manager.Provide<ICar>()
	.Query.Where(c => c.YearOfAssembly == 2009);
	foreach (var car in collection)
	Console.WriteLine(car.Name);
	}

view raw 03.cs hosted with ❤ by GitHub

Almost the same example for single object and count function:

	using (var manager = AcroDataContext.Go)
	{
	//We will find one car assembled in 2009 and which is first in our db
	var car = manager.Provide<ICar>()
	.Query.Where(c => c.YearOfAssembly == 2009).First();
	Console.WriteLine(car.Name);
	}

view raw 04.cs hosted with ❤ by GitHub

As you can see, here you can use usual Linq methods applying to the Query property, as Query property is IQueryabe type.

Updating and deleting an entity

	using (var manager = AcroDataContext.Go)
	{
	//Object search and changing
	var car = manager.Provide<ICar>()
	.Query.Where(c => c.YearOfAssembly == 2009).First();
	car.Name = "Mitsubisi Lancer (Red)";
	manager.Provide<ICar>().Save(car);
	manager.SubmitChanges();

	//Deleting an entity
	manager.Provide<ICar>().Delete(car);
	//Don't forget to submit changes even after delete
	manager.SubmitChanges();
	}

view raw 05.cs hosted with ❤ by GitHub

The end for today

As you can see, I have tried to save the simplicity in working with objects as in Linq2Sql, but have added a multi-context support for it, so you are not limited only for MS SQL...

Also, you don't need to work with db directly. All tables/objects will be created for you automatically.

If you have any comments/proposals please, write them in comment form. Next time I plan to describe, how to use simple business logic layer with AcroDb and relations between entities.

AcroDB. How to use C#