Generic linq-to-sql repository

A generic linq-to-sql class for easy, strongly-typed data access

1.04k

Repository interface:

public interface IRepository<T>
{
    IEnumerable<T> GetAll();
    IEnumerable<T> Get(Func<T, bool> exp);
    void Insert(T entity);
    void CommitChanges();
}

Implementation:

    public class LinqToSqlRepository<T> : IRepository<T> where T : class
    {
        private DataContext _db;

        public LinqToSqlRepository(DataContext db)
        {
        	_db = db;
        }

        protected Table<T> GetTable()
        {
        	return _db.GetTable<T>();
        }

        public IEnumerable<T> GetAll()
        {
        	return GetTable().AsQueryable();
        }

        public IEnumerable<T> Get(Func<T, bool> exp)
        {
        	return GetTable().Where(exp);
        }

        public void Insert(T entity)
        {
        	GetTable().InsertOnSubmit(entity);
        }

        public void CommitChanges()
        {
        	_db.SubmitChanges();
        }
    }

A fake repository for used with tests:

public class InMemoryRepository<T> : IRepository<T> where T : class
{
    private readonly IList<T> _storage;

    public InMemoryRepository(IList<T> storage)
    {
    	_storage = storage;
    }

    public IEnumerable<T> GetAll()
    {
    	return _storage.AsEnumerable();
    }

    public IEnumerable<T> Get(Func<T, bool> exp)
    {
    	return _storage.Where(exp);
    }

    public void Insert(T entity)
    {
    	_storage.Add(entity);
    }

    public void CommitChanges()
    {

    }
}

The DataContext passed to LinqToSqlRepository should be a UoW implementation. The repository could handle all the disposal by itself but i found it more useful to do explicitly do that.

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.net c# linq-to-sql repository

alexandern
110

September 29, 2010 10:59 PM

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Generic linq-to-sql repository - alexandern Wednesday 29, 2010 10:59 PM

2 Feedback

What happens if you don't need Insert in some of your repositories? - @johannormen Thursday 30, 2010 1:35 PM

What about disposing the external resources as the db connection? - @lennybacon Thursday 21, 2010 11:39 AM

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3 Discussion(s)

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Doens't bring any value to the discussion

@johannormen Well, in this case you must implement the Insert method signature, but you can skip implementing the method body.

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alexandern
110

Thursday 30, 2010 5:46 PM

public interface IRepository<T> : IDisposable
{
    IEnumerable<T> GetAll();
    IEnumerable<T> Get(Func<T, bool> exp);
    void Insert(T entity);
    void CommitChanges();
}

public class LinqToSqlRepository<T> : IRepository<T> where T : class
{
    private DataContext _db;

    public LinqToSqlRepository()
    {
        var connStr =
            ConfigurationManager.
                ConnectionStrings["RepositoryConnection"].
                    ConnectionString;
        _db = new DataContext(connStr);
    }

    public LinqToSqlRepository(DataContext db)
    {
        _db = db;
    }

    protected Table<T> GetTable()
    {
        return _db.GetTable<T>();
    }

    public IEnumerable<T> GetAll()
    {
        return GetTable().AsQueryable();
    }

    public IEnumerable<T> Get(Func<T, bool> exp)
    {
        return GetTable().Where(exp);
    }

    public void Insert(T entity)
    {
        GetTable().InsertOnSubmit(entity);
    }

    public void CommitChanges()
    {
        _db.SubmitChanges();
    }

    /// <summary>
    /// Performs application-defined tasks associated with freeing, releasing, or resetting unmanaged resources.
    /// </summary>
    /// <filterpriority>2</filterpriority>
    public void Dispose()
    {
        _db.Dispose();
    }
}

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@lennybacon
222

Thursday 21, 2010 11:40 AM

Reply to: lennybacon

A Perfect Fork, try that feature ;)

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@fredrikn "I'm the master"
3.11k

Thursday 21, 2010 12:22 PM

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