.NetCore学习笔记：二、基于Dapper的泛型Repository

为减少代码量，这里实现一个基于Dapper的泛型Repository。

这里需要引用Dapper.dll和Dapper.Contrib.dll。

接口定义：

 /// <summary>
 /// Repository接口
 /// </summary>
 /// <typeparam name="T"></typeparam>
 public interface IRepository<T> where T : class, IEntity
 {
     /// <summary>
     /// 查询
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="sql"></param>
     /// <param name="param"></param>
     /// <param name="commandType"></param>
     /// <returns></returns>
     IEnumerable<T> Query(string sql, object param = null, CommandType? commandType = null);

     /// <summary>
     /// 删除行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entity"></param>
     /// <returns></returns>
     bool Delete(T entity);
     /// <summary>
     /// 删除表所有数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
     bool DeleteAll();
     /// <summary>
     /// 获取行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="id"></param>
     /// <returns></returns>
     T Get(object id);
     /// <summary>
     /// 获取表的所有数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
     IEnumerable<T> GetAll();
     /// <summary>
     /// 添加行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entity"></param>
     /// <returns></returns>
     long Insert(T entity);
     /// <summary>
     /// 更新行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entity"></param>
     /// <returns></returns>
     bool Update(T entity);

     /// <summary>
     /// 分页方法
     /// </summary>
     /// <param name="sql"></param>
     /// <param name="pageIndex">当前页码</param>
     /// <param name="pageSize">每页显示条数</param>
     /// <param name="param">参数</param>
     /// <param name="transaction"></param>
     /// <param name="commandTimeout"></param>
     /// <returns></returns>
     PagedResult<T> GetPageList(string sql, int pageIndex, int pageSize, object param = null);
 }

接口实现：

 /// <summary>
 /// 泛型Repository
 /// </summary>
 /// <typeparam name="T"></typeparam>
 public class Repository<T> : IRepository<T> where T : class, IEntity
 {
     private IUnitOfWork _unitOfWork;

     public Repository(IUnitOfWork unitOfWork)
     {
         _unitOfWork = unitOfWork;
     }
     /// <summary>
     /// 查询
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="sql"></param>
     /// <param name="param"></param>
     /// <param name="commandType"></param>
     /// <returns></returns>
     public IEnumerable<T> Query(string sql, object param = null, CommandType? commandType = null)
     {
         var r = _unitOfWork.DbConnection.Query<T>(sql, param: param, transaction: _unitOfWork.DbTransaction, commandType: commandType);
         return r;
     }
     /// <summary>
     /// 删除行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entityToDelete"></param>
     /// <returns></returns>
     public bool Delete(T entity)
     {
         var r = _unitOfWork.DbConnection.Delete<T>(entity, _unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 删除表所有数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
     public bool DeleteAll()
     {
         var r = _unitOfWork.DbConnection.DeleteAll<T>(_unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 获取行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="id"></param>
     /// <returns></returns>
     public T Get(object id)
     {
         var r = _unitOfWork.DbConnection.Get<T>(id, _unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 获取表的所有数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <returns></returns>
     public IEnumerable<T> GetAll()
     {
         var r = _unitOfWork.DbConnection.GetAll<T>(_unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 添加行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entity"></param>
     /// <returns></returns>
     public long Insert(T entity)
     {
         var r = _unitOfWork.DbConnection.Insert<T>(entity, _unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 更新行数据
     /// </summary>
     /// <typeparam name="T"></typeparam>
     /// <param name="entity"></param>
     /// <returns></returns>
     public bool Update(T entity)
     {
         var r = _unitOfWork.DbConnection.Update<T>(entity, _unitOfWork.DbTransaction);
         return r;
     }
     /// <summary>
     /// 分页方法
     /// </summary>
     /// <param name="sql"></param>
     /// <param name="pageIndex">当前页码</param>
     /// <param name="pageSize">每页显示条数</param>
     /// <param name="param">参数</param>
     /// <param name="transaction"></param>
     /// <param name="commandTimeout"></param>
     /// <returns></returns>
     public PagedResult<T> GetPageList(string sql, int pageIndex, int pageSize, object param = null)
     {
        var pagingResult =  _unitOfWork.DbConnection.GetPageList<T>(sql, pageIndex, pageSize, param: param, transaction: _unitOfWork.DbTransaction);
         return pagingResult;
     }
 }

GetPageList为Dapper的一个分页扩展：

 /// <summary>
 /// 分页方法
 /// </summary>
 /// <param name="sql"></param>
 /// <param name="pageIndex">当前页码</param>
 /// <param name="pageSize">每页显示条数</param>
 /// <param name="param">参数</param>
 /// <param name="transaction"></param>
 /// <param name="commandTimeout"></param>
 /// <returns></returns>
 public static PagedResult<T> GetPageList<T>(this IDbConnection connection, string sql, int pageIndex, int pageSize, object param = null, IDbTransaction transaction = null, int? commandTimeout = null)
 {
     if (pageIndex < ) pageIndex = ;
     if (pageSize < ) pageSize = ;
     var startRow = (pageIndex - ) * pageSize;

     //MySql分页
     sql = $"SELECT * FROM ({sql}) tt1  LIMIT {startRow},{pageSize};  SELECT COUNT(1) FROM ({sql}) tt2;";

     PagedResult<T> pagingResult = new PagedResult<T>();
     pagingResult.Paged.PageIndex = pageIndex;
     pagingResult.Paged.PageSize = pageSize;
     using (var result = connection.QueryMultiple(sql, param: param, transaction, commandTimeout))
     {
         var list = result.Read<T>();
         var totalCount = result.Read<long>().FirstOrDefault();
         pagingResult.Data = list;
         pagingResult.Paged.TotalRow = totalCount;
     }
     return pagingResult;
 }

PagedResult类：

 /// <summary>
 /// 分页模型
 /// </summary>
 /// <typeparam name="T"></typeparam>
 public class PagedResult<T>
 {
     public PagedResult()
     {
         this.Paged = new Paged();
     }

     /// <summary>
     /// 结果
     /// </summary>
     public IEnumerable<T> Data { get; set; }

     /// <summary>
     /// 分页数据，包含数据总行数、当前页码、页数据行数和总的分页数
     /// </summary>
     public Paged Paged { get; set; }
 }

Paged类：

 /// <summary>
 /// 分页数据
 /// </summary>
 public class Paged
 {
     /// <summary>
     /// 当前页码
     /// </summary>
     public int PageIndex { get; set; }
     /// <summary>
     /// 页数据行数
     /// </summary>
     public int PageSize { get; set; }
     /// <summary>
     /// 总行数
     /// </summary>
     public long TotalRow { get; set; }
     /// <summary>
     /// 总的分页数
     /// </summary>
     public int TotalPage
     {
         get
         {
             if (this.TotalRow >  && this.PageSize > )
                 return (int)Math.Ceiling((decimal)this.TotalRow / this.PageSize);
             else
                 return ;
         }
     }
 }

在IServiceCollection容器中注册：

services.AddScoped(typeof(IRepository<>), typeof(Repository<>));

源码地址：https://github.com/letnet/NetCoreDemo