如何使用ADO.NET和存储过程在数据库中保存复杂的C＃对象？

Question

I have a complex C# object which needs to be persisted in multiple tables (around 12) in the database:

class Foo
{
    public Guid FooId { get; set; }
    public Bar[] Bars { get; set; }
}

class Bar
{
    public Guid BarId { get; set; }
    public Guid FooId { get; set; }
    public Baz[] Bazs { get; set; }
}

class Baz
{
    public Guid BazId { get; set; }
    public Guid BarId { get; set; }
    // And so on ...
}

Questions:

1. What is the best way to send this complex object (an instance of Foo ) as input to the stored procedure?
2. In the stored procedure how can I relate the corresponding Foo , Bar and Baz tables with its parent Ids (ex. Bar needs its parent FooId )?

Answer 1

Here is a rough outline of how you might want to consider modeling it. This isn't by any means a complete skeleton (as you may want to play with the scope a bit), but should give a general idea. I've used models similar to this in several projects.

It may be possible to abstract these classes if they all follow the same type of data model.

class Foo
{
    public Guid FooId { get; private set; } // Only allow the object to define its Id.
    public List<Bar> Bars { get; set; } // Use a dynamic storage object.
    private bool Deleted { get; set; } // Monitors if the object has been deleted in the DB.

    public Foo()
    {
        this.FooId = Guid.Empty;
        this.Deleted = false;
        Bars = new List<Bar>();
    }

    public Foo(Guid fooId)
    {
        this.Deleted = false;

        this.FooId = fooId;
        LoadFromDatabase();

        Bars = new List<Bar>();
        LoadBarsFromDatabase();
    }

    private void LoadFromDatabase()
    {
        // Read from DB, set local variables...
    }

    private void LoadBarsFromDatabase()
    {
        // Psuedocode to load all Bars.
        foreach (var barData in barIdsLinkedToFooTable.Rows)
        {
            Bars.Add(new Bar(this, barData["barId"]));
        }
    }

    public void SaveToDatabase()
    {
        // If FooId is Guid.Empty, the record is new.
        // You may also want to consider the Deleted property value.
        // Either generate the new Guid first or let SQL do it for you in your SP.

        // Save Foo to DB with stored proc.

        // Save Bars.
        foreach (var bar in Bars)
        {
            bar.SaveToDatabase();
        }
    }

    public void Delete()
    {
        // Delete via a stored proc.
        // Might be a good idea to set SQL to cascade the delete,
        //  this way all the children will be deleted automatically.

        this.Deleted = true;
    }
}

class Bar
{
    public Guid BarId { get; private set; } // Only allow the local object to generate Id.
    public Foo ParentFoo { get; set; } // Store a reference to the parent.
    public List<Baz> Bazs { get; set; } // Use a dynamic storage object.
    private bool Deleted { get; set; } // Monitors if the object has been deleted in the DB.

    public Bar(Foo parentFoo)
    {
        // New Bar object.
        this.BarId = Guid.Empty;
        this.ParentFoo = parentFoo;
        this.Bazs = new List<Baz>();
        this.Deleted = false;
    }

    public Bar(Foo parentFoo, Guid barId)
    {
        // Create from existing object.
        this.Deleted = false;

        this.BarId = barId;
        this.ParentFoo = parentFoo;
        LoadFromDatabase();

        Bazs = new List<Baz>();
        LoadBazsFromDatabase();
    }

    /* DB methods for load, save, and delete similar to above. */
}

Answer 2

In theory you should serialize your complex object into XML and pass it as parameter to stored procedure.

In stored procedure code you can query this XML. TSQL Parse XML in Stored Procedure

In result you can reach high performance, but this way may become too difficult to maintain because stored procedure must know how to proceed your complex object.