ASP.NET MVC通用存储库
本文关键字：存储 NET MVC ASP | 更新日期: 2023-09-27 18:00:16
我已经搜索了几个小时，并且读了几篇关于构建通用存储库（GR）的文章。据我所知，GR用于存在类似代码的情况。例如，通过表的id从表中提取一行，或者整个表。然而，我仍然无法理解如何实现这一点。
public interface IEntity<T> where T : class{
IQueryable<T> getAll();
T GetById(int id);
}
public class Repository<T> where T : IEntity<T>{
northWindDataContext nwdc = new northWindDataContext();
public IQueryable<T> getAll()
{
//code to retrive the whole table
}
public T GetById(int id)
{
//code to retrieve a single row (don't know how to do)
}
}
然后，我想做一些类似的事情：
Repository<User> rep = new Repository<User>();
IQueryable<User> = rep.getAll<User>;
User user = rep.GetById(35);
有人能告诉我如何完成这项任务吗？
这只是一个创建强类型通用存储库的伪代码。
public interface IRepository<TEntity> : IDisposable where TEntity : class
{
IQueryable<TEntity> GetAll { get; }
IEntity GetById(int id) { get; }
}
public class EntityRepository<TEntity> : IRepository<TEntity> where TEntity : class
{
private IContext context;
private IObjectSet<TEntity> objectSet;
private IObjectSet<TEntity> ObjectSet
{
get
{
if (this.objectSet == null)
{
var entitySetProperty = this.Context.GetType().GetProperties().Single(p => p.PropertyType.IsGenericType && typeof(IQueryable<>).MakeGenericType(typeof(TEntity)).IsAssignableFrom(p.PropertyType));
this.objectSet = (IObjectSet<TEntity>)entitySetProperty.GetValue(this.Context, null);
}
return this.objectSet;
}
}
public IQueryable<TEntity> GetAll
{
get
{
return this.ObjectSet;
}
}
}
然后你可以创建一个特定的存储库界面，比如
public interface IUserRepository : IRepository<User>
{
// some additional properties specific to User repository
...
}
public class UserRepository : EntityRepository<User>, IUserRepository
{
public UserRepository(IUnitOfWork uow)
: base(uow)
{
}
}
不知道这是不是你想要的。如果您正在使用EF。
我一直在使用这里描述的通用存储库。我的代码一直使用作者的设计，效果非常好。这是我一直在使用的代码：
库存
namespace New_Repository_Design.Repositories
{
using System;
using System.Collections.Generic;
using System.Data.SqlClient;
using System.Linq;
using System.Linq.Expressions;
using Specifications;
public interface IRepository
{
/// <summary>
/// Gets entity by key.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="keyValue">The key value.</param>
/// <returns></returns>
TEntity GetByKey<TEntity>(object keyValue) where TEntity : class;
/// <summary>
/// Gets the query.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <returns></returns>
IQueryable<TEntity> GetQuery<TEntity>() where TEntity : class;
/// <summary>
/// Gets the query.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="predicate">The predicate.</param>
/// <returns></returns>
IQueryable<TEntity> GetQuery<TEntity>(Expression<Func<TEntity, bool>> predicate) where TEntity : class;
/// <summary>
/// Gets the query.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
IQueryable<TEntity> GetQuery<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Gets one entity based on matching criteria
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
TEntity Single<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class;
/// <summary>
/// Gets single entity using specification
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
TEntity Single<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Firsts the specified predicate.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="predicate">The predicate.</param>
/// <returns></returns>
TEntity First<TEntity>(Expression<Func<TEntity, bool>> predicate) where TEntity : class;
/// <summary>
/// Gets first entity with specification.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
TEntity First<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Adds the specified entity.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="entity">The entity.</param>
void Add<TEntity>(TEntity entity) where TEntity : class;
/// <summary>
/// Attaches the specified entity.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="entity">The entity.</param>
void Attach<TEntity>(TEntity entity) where TEntity : class;
/// <summary>
/// Deletes the specified entity.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="entity">The entity.</param>
void Delete<TEntity>(TEntity entity) where TEntity : class;
/// <summary>
/// Deletes one or many entities matching the specified criteria
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
void Delete<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class;
/// <summary>
/// Deletes entities which satify specificatiion
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
void Delete<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Updates changes of the existing entity.
/// The caller must later call SaveChanges() on the repository explicitly to save the entity to database
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="entity">The entity.</param>
void Update<TEntity>(TEntity entity) where TEntity : class;
/// <summary>
/// Finds entities based on provided criteria.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
IEnumerable<TEntity> Find<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Finds entities based on provided criteria.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
IEnumerable<TEntity> Find<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class;
/// <summary>
/// Finds one entity based on provided criteria.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
TEntity FindOne<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
/// <summary>
/// Finds one entity based on provided criteria.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
TEntity FindOne<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class;
/// <summary>
/// Gets all.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <returns></returns>
IEnumerable<TEntity> GetAll<TEntity>() where TEntity : class;
/// <summary>
/// Gets a collection of entity with paging support
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="orderBy">The order by.</param>
/// <param name="pageIndex">Index of the page.</param>
/// <param name="pageSize">Size of the page.</param>
/// <param name="sortOrder">The sort order.</param>
/// <returns></returns>
IEnumerable<TEntity> Get<TEntity>(Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class;
/// <summary>
/// Gets a collection of entity base on criteria with paging support
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <param name="orderBy">The order by.</param>
/// <param name="pageIndex">Index of the page.</param>
/// <param name="pageSize">Size of the page.</param>
/// <param name="sortOrder">The sort order.</param>
/// <returns></returns>
IEnumerable<TEntity> Get<TEntity>(Expression<Func<TEntity, bool>> criteria, Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class;
/// <summary>
/// Gets entities which satify specification
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <param name="orderBy">The order by.</param>
/// <param name="pageIndex">Index of the page.</param>
/// <param name="pageSize">Size of the page.</param>
/// <param name="sortOrder">The sort order.</param>
/// <returns></returns>
IEnumerable<TEntity> Get<TEntity>(ISpecification<TEntity> criteria, Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class;
/// <summary>
/// Counts the specified entities.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <returns></returns>
int Count<TEntity>() where TEntity : class;
/// <summary>
/// Counts entities with the specified criteria.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
int Count<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class;
/// <summary>
/// Counts entities satifying specification.
/// </summary>
/// <typeparam name="TEntity">The type of the entity.</typeparam>
/// <param name="criteria">The criteria.</param>
/// <returns></returns>
int Count<TEntity>(ISpecification<TEntity> criteria) where TEntity : class;
}
}
DomainRepository
namespace New_Repository_Design.Repositories
{
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.Entity.Design.PluralizationServices;
using System.Data.Objects;
using System.Data.SqlClient;
using System.Globalization;
using System.Linq;
using System.Linq.Expressions;
using Specifications;
public sealed class DomainRepository : IRepository
{
private readonly PluralizationService _pluralizer = PluralizationService.CreateService(CultureInfo.GetCultureInfo("en"));
private readonly string _connectionStringName;
private ObjectContext _objectContext;
/// <summary>
/// Initializes a new instance of the <see cref="GenericRepository<TEntity>"/> class.
/// </summary>
public DomainRepository()
: this(string.Empty)
{
}
/// <summary>
/// Initializes a new instance of the <see cref="GenericRepository<TEntity>"/> class.
/// </summary>
/// <param name="connectionStringName">Name of the connection string.</param>
public DomainRepository(string connectionStringName)
{
this._connectionStringName = connectionStringName;
}
/// <summary>
/// Initializes a new instance of the <see cref="GenericRepository"/> class.
/// </summary>
/// <param name="objectContext">The object context.</param>
public DomainRepository(ObjectContext objectContext)
{
if (objectContext == null)
throw new ArgumentNullException("objectContext");
this._objectContext = objectContext;
}
public TEntity GetByKey<TEntity>(object keyValue) where TEntity : class
{
EntityKey key = GetEntityKey<TEntity>(keyValue);
object originalItem;
if (ObjectContext.TryGetObjectByKey(key, out originalItem))
{
return (TEntity)originalItem;
}
return default(TEntity);
}
public IQueryable<TEntity> GetQuery<TEntity>() where TEntity : class
{
var entityName = GetEntityName<TEntity>();
var q = ObjectContext.CreateQuery<TEntity>(entityName);
//return ObjectContext.CreateQuery<TEntity>(entityName);
return q;
}
public IQueryable<TEntity> GetQuery<TEntity>(Expression<Func<TEntity, bool>> predicate) where TEntity : class
{
return GetQuery<TEntity>().Where(predicate);
}
public IQueryable<TEntity> GetQuery<TEntity>(ISpecification<TEntity> specification) where TEntity : class
{
return specification.SatisfyingEntitiesFrom(GetQuery<TEntity>());
}
public IEnumerable<TEntity> Get<TEntity>(Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class
{
if (sortOrder == SortOrder.Ascending)
{
return GetQuery<TEntity>().OrderBy(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
return GetQuery<TEntity>().OrderByDescending(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
public IEnumerable<TEntity> Get<TEntity>(Expression<Func<TEntity, bool>> predicate, Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class
{
if (sortOrder == SortOrder.Ascending)
{
return GetQuery<TEntity>().Where(predicate).OrderBy(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
return GetQuery<TEntity>().Where(predicate).OrderByDescending(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
public IEnumerable<TEntity> Get<TEntity>(ISpecification<TEntity> specification, Expression<Func<TEntity, string>> orderBy, int pageIndex, int pageSize, SortOrder sortOrder = SortOrder.Ascending) where TEntity : class
{
if (sortOrder == SortOrder.Ascending)
{
return specification.SatisfyingEntitiesFrom(GetQuery<TEntity>()).OrderBy(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
return specification.SatisfyingEntitiesFrom(GetQuery<TEntity>()).OrderByDescending(orderBy).Skip(pageIndex).Take(pageSize).AsEnumerable();
}
public TEntity Single<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class
{
return GetQuery<TEntity>().SingleOrDefault<TEntity>(criteria);
}
public TEntity Single<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
return criteria.SatisfyingEntityFrom(GetQuery<TEntity>());
}
public TEntity First<TEntity>(Expression<Func<TEntity, bool>> predicate) where TEntity : class
{
return GetQuery<TEntity>().FirstOrDefault(predicate);
}
public TEntity First<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
return criteria.SatisfyingEntitiesFrom(GetQuery<TEntity>()).FirstOrDefault();
}
public void Add<TEntity>(TEntity entity) where TEntity : class
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
ObjectContext.AddObject(GetEntityName<TEntity>(), entity);
}
public void Attach<TEntity>(TEntity entity) where TEntity : class
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
ObjectContext.AttachTo(GetEntityName<TEntity>(), entity);
}
public void SaveChanges()
{
this.ObjectContext.SaveChanges();
}
public void Delete<TEntity>(TEntity entity) where TEntity : class
{
if (entity == null)
{
throw new ArgumentNullException("entity");
}
ObjectContext.DeleteObject(entity);
}
public void Delete<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class
{
IEnumerable<TEntity> records = Find<TEntity>(criteria);
foreach (TEntity record in records)
{
Delete<TEntity>(record);
}
}
public void Delete<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
IEnumerable<TEntity> records = Find<TEntity>(criteria);
foreach (TEntity record in records)
{
Delete<TEntity>(record);
}
}
public IEnumerable<TEntity> GetAll<TEntity>() where TEntity : class
{
return GetQuery<TEntity>().AsEnumerable();
}
public void Update<TEntity>(TEntity entity) where TEntity : class
{
var fqen = GetEntityName<TEntity>();
object originalItem;
EntityKey key = ObjectContext.CreateEntityKey(fqen, entity);
if (ObjectContext.TryGetObjectByKey(key, out originalItem))
{
ObjectContext.ApplyCurrentValues(key.EntitySetName, entity);
}
}
public IEnumerable<TEntity> Find<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class
{
return GetQuery<TEntity>().Where(criteria);
}
public TEntity FindOne<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class
{
return GetQuery<TEntity>().Where(criteria).FirstOrDefault();
}
public TEntity FindOne<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
return criteria.SatisfyingEntityFrom(GetQuery<TEntity>());
}
public IEnumerable<TEntity> Find<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
return criteria.SatisfyingEntitiesFrom(GetQuery<TEntity>());
}
public int Count<TEntity>() where TEntity : class
{
return GetQuery<TEntity>().Count();
}
public int Count<TEntity>(Expression<Func<TEntity, bool>> criteria) where TEntity : class
{
return GetQuery<TEntity>().Count(criteria);
}
public int Count<TEntity>(ISpecification<TEntity> criteria) where TEntity : class
{
return criteria.SatisfyingEntitiesFrom(GetQuery<TEntity>()).Count();
}
private ObjectContext ObjectContext
{
get
{
return this._objectContext;
}
}
private string GetEntityName<TEntity>() where TEntity : class
{
return string.Format("{0}.{1}", ObjectContext.DefaultContainerName, _pluralizer.Pluralize(typeof(TEntity).Name));
}
private EntityKey GetEntityKey<TEntity>(object keyValue) where TEntity : class
{
var entitySetName = GetEntityName<TEntity>();
var objectSet = ObjectContext.CreateObjectSet<TEntity>();
var keyPropertyName = objectSet.EntitySet.ElementType.KeyMembers[0].ToString();
var entityKey = new EntityKey(entitySetName, new[] { new EntityKeyMember(keyPropertyName, keyValue) });
return entityKey;
}
}
}`
例如，通过ID获取物品。
DomainRepository.FindOne<User>(u => u.Id == userId);
将返回单个用户。或
DomainRepository.Find<User>(u => u.UserName.Contains("Blah"));
试用这个存储库，看看它是否适合您的需求。