Repository pattern: One repository class for each entity?

Question

Say you have the following entities defined in a LINQ class:

Product
Customer
Category

Should I have one repository class for all:

Answer 1

I'd have one repository/object because invariably, there'd need to be a map from my EntityTable to my domain object (such as in the body of the GetIQueryableCollection(). How I got around writing this repetitive code is by making a T4 template to generate it for me.

I have an example project which generates the repository pattern on codeplex http://t4tarantino.codeplex.com/ T4 Toolbox example Templates for business classes and repository. It may not work exactly the way you'd like without some tweaking, unless you're already implementing Tarintino and a few other goodies, but the templates are easy to configure.

using System;
using System.Collections.Generic;
using System.Linq;
using Cses.Core.Domain.Model;
using StructureMap;

namespace Cses.Core.Domain
{
    /// 

    /// Core class for Schedule E
    /// 
    public class ScheduleERepository : IScheduleERepository
    {

        private Cses.Core.Repository.SqlDataContext _context = new Cses.Core.Repository.SqlDataContext();

        /// 

        /// constructor
        /// 
        public ScheduleERepository() { }

        /// 

        /// constructor for testing
        /// 
        /// 
        public ScheduleERepository(Cses.Core.Repository.SqlDataContext context)
        {
            _context = context;

        }

        /// 

        /// returns collection of scheduleE values
        /// 
        /// 
        public IQueryable GetIQueryableCollection()
        {           
            return from entity in _context.ScheduleEs                  
               select new ScheduleE()
               {    
                    Amount = entity.Amount,
                    NumberOfChildren = entity.NumberChildren,
                    EffectiveDate = entity.EffectiveDate,
                    MonthlyIncome = entity.MonthlyIncome,
                    ModifiedDate = entity.ModifiedDate,
                    ModifiedBy = entity.ModifiedBy,                      
                    Id = entity.Id                          
               };           
        }