Dapper.Contrib AS Entity, Why it fails?

Question

Iam planning to use Contrib with dapper to make my classes in desktop applications look like this

public abstract class DB : IDisposable
{
    public virtual long Insert()
    {
        using (var db = ConFactory.GetConnection())
        {
            db.Open();
            return db.Insert(this);
        }
    }
// ... and other CRUD operations 
}

then any Concept class will inherits from DB class; like this

[Table("test")]
public class Test : DB
{
    [Key]
    public int TestId { get; set; }
    public string Name { get; set; } 
}

using Test class

using (Test t = new Test { Name = textBox2.Text })
{
    textBox1.Text = t.Insert().ToString();
}

this sample always fails and gives me

SQL logic error near ")": syntax error

BUT when I implement Insert() method inside child class it works well !!! the problem is: my code contains lot of classes, rewrite All CUD operations is so disturbing, any idea to solve this with less code?

I would strongly advise against putting anything into your domain classes. Keep them clean and lean. — DavidG, Mar 20 '18 at 18:59
OK Thanks I'll keep that in mind :), what about this? is it clean enough? — msh, Mar 20 '18 at 19:22
If you run a SQL Trace, what was the SQL being submitted to the database? — mjwills, Mar 20 '18 at 20:41
I cannot find good SQL tracer works well with dapper & SQLite !!! do you have one? — msh, Mar 21 '18 at 11:45

score 0 · Accepted Answer · answered Mar 22 '18 at 22:52

I figured out a better way to solve this... which is more flexible and more pro i think. I'll put the solution here ... soon on github

the solution based on Extension methods, to inject CUD operation with only concept classes I proposed IDbTable base class

public abstract class IDbTable : IDisposable
{
    public void Dispose()
    {
        // do disposing if you need
    }
}

public static class DB
{
    public static long Insert<T>(this T entity) where T : IDbTable
    {
        using (var db = ConFactory.GetConnection())
        {
                db.Open();
                return db.Insert(entity);
        }
    }
    public static void Delete<T>(this T entity) where T : IDbTable
    {
            using (var db = ConFactory.GetConnection())
            {
                db.Open();
                db.Delete(entity);
            }
    }
    public static void Update<T>(this T entity) where T : IDbTable
    {
            using (var db = ConFactory.GetConnection())
            {
                db.Open();
                SqlMapperExtensions.Update(db, entity);
            }
    }

    public static T Get<T>(int id)
    {
        using (var db = ConFactory.GetConnection())
        {
            db.Open();
            return db.Get<T>(id);
        }
    }
}

ok this is all

when any class inherits from IDbTable base class, it have insert, update and delete method as extenssion

[Table("test")]
public class Test : IDbTable
{
    [Key]
    public int TestId { get; set; }
    public string Name { get; set; }
}

.......

Test t = new Test { Name = textBox2.Text };
textBox1.Text = t.Insert().ToString();

AND it WORKS fine !!!

any suggestion to improve will be appreciated.

Dapper.Contrib AS Entity, Why it fails?

1 Answers1