自己写的Dapper通用数据访问层

    using Microsoft.Practices.EnterpriseLibrary.Data;
    using Microsoft.Practices.EnterpriseLibrary.Data.Oracle;
    using System;
    using System.Collections.Generic;
    using System.Data;
    using System.Data.Common;
    using System.Data.OleDb;
    using System.Linq;
    using System.Text;
   using System.Threading.Tasks;
   using Dapper;
   using System.Collections;
   using System.Reflection;
   using Knet.H5.Entity.Core;

   namespace Knet.H5.Toolkit.Data.Core
   {
       public class DapperDBase<T> where T : class,new()
       {
           public string TableName { get; set; }
           public string Primarykey { get; set; }
           public List<string> CoulmnsList { get; set; }
           public DapperDBase()
           {
               var tablenameAttribute = (TableAttribute)Attribute.GetCustomAttribute(typeof(T), typeof(TableAttribute));
               Primarykey = tablenameAttribute.PrimaryKey;
               TableName = tablenameAttribute.TableName;
               CoulmnsList = GetEntityProperties(typeof(T));
           }

           /// 得到web.config里配置项的数据库连接字符串。
           private static readonly string connectionString = "Data Source=(DESCRIPTION=(ADDRESS_LIST=(ADDRESS=(PROTOCOL=TCP)(HOST=)(PORT=1521)))(CONNECT_DATA=(SERVICE_NAME=ora9)));User Id=;Password=;";

           private static DbConnection _db;

           private static readonly object objLocker = new object();

           public static DbConnection DB
           {
               get
               {
                   if (_db == null)
                   {
                       lock (objLocker)
                       {
                           if (_db == null)
                           {
                               Database Db = new OracleDatabase(connectionString);
                               DbConnection connection = Db.CreateConnection();
                               return connection;
                           }
                       }
                   }
                   return _db;
               }
           }

           /// <summary>
           /// 根据ID获取model
           /// </summary>
           /// <param name="Id"></param>
           /// <returns></returns>
           public T GetModelById(object Id)
           {
               string executeSql = @" SELECT " + string.Join(",", CoulmnsList) + " FROM  " + this.TableName + " WHERE ID = :ID ";
               var conditon = new { ID = Id };
               return DB.Query<T>(executeSql, conditon).SingleOrDefault() ?? default(T);
           }

           /// <summary>
           /// 根据ID获取model
           /// </summary>
           /// <param name="Id"></param>
           /// <returns></returns>
           public T GetModelById(object Id, params string[] selectCoumlns)
           {
               var selectFields = string.Empty;
               if (selectCoumlns.Length > )
               {
                   selectFields = string.Join<string>(",", selectCoumlns);
               }
               else
               {
                   selectFields = string.Join(",", CoulmnsList);
               }
               string executeSql = @" SELECT " + selectFields + " FROM " + this.TableName + "  WHERE " + this.Primarykey + " = :ID ";
               var conditon = new { ID = Id };
               return DB.Query<T>(executeSql, conditon).SingleOrDefault() ?? default(T);
           }

           /// <summary>
           /// 根据ID获取model
           /// </summary>
           /// <param name="Id"></param>
           /// <returns></returns>
           public T GetModelByWhere(object whereObj)
           {
               var wherePro = whereObj.GetType().GetProperties();
               var whereList= new List<string>();
              foreach (var item in wherePro)
              {
                  if (item.GetValue(whereObj) == null) continue;
                  whereList.Add(string.Format("{0}=:{0}", item.Name));
              }
              string executeSql = @" SELECT " + string.Join(",", CoulmnsList) + " FROM " + this.TableName;
              if (whereList.Count > )
              {
                  executeSql += " WHERE " + string.Join(" AND ", whereList);
              }
              return DB.Query<T>(executeSql, whereObj).SingleOrDefault() ?? default(T);
          }

          /// <summary>
          /// 获取列表
          /// </summary>
          /// <param name="whereStr">只能使用且的关系，且属于该model内的字段</param>
          /// <param name="order">排序字段 create_date desc</param>
          /// <returns></returns>
          public List<T> GetList(object whereObj = null, string order = null)
          {
              var whereList = new List<string>();
              if (whereObj != null)
              {
                  var wherePro = whereObj.GetType().GetProperties();
                  foreach (var item in wherePro)
                  {
                      if (item.GetValue(whereObj) == null) continue;
                      whereList.Add(string.Format("{0}=:{0}", item.Name));
                  }
              }
              string executeSql = @" SELECT " + string.Join(",", CoulmnsList) + " FROM  " + this.TableName;
              if (whereList.Count > )
              {
                  executeSql += " WHERE " + string.Join(" and ", whereList);
              }
              if (!string.IsNullOrEmpty(order))
              {
                  executeSql += " ORDER BY " + order;
              }
              return DB.Query<T>(executeSql, whereObj).ToList();
          }

          /// <summary>
          /// 获取列表
          /// </summary>
          /// <param name="whereStr">只能使用且的关系，且属于该model内的字段</param>
          /// <param name="order">排序字段 create_date desc</param>
          /// <returns></returns>
          public List<T> GetList(string whereStr = null, string order = null)
          {
              string executeSql = @" SELECT " + string.Join(",", CoulmnsList) + " FROM  " + this.TableName;
              if (!string.IsNullOrEmpty(whereStr))
              {
                  executeSql += " where " + whereStr;
              }
              if (!string.IsNullOrEmpty(order))
              {
                  executeSql += "order by " + order;
              }
              return DB.Query<T>(executeSql, whereStr).ToList();
          }

          /// <summary>
          /// 获取全部字段
          /// </summary>
          /// <param name="order">排序</param>
          /// <returns></returns>
          public List<T> GetAllList(string order = null)
          {
              string executeSql = @" SELECT " + string.Join(",", CoulmnsList) + " FROM  " + this.TableName;
              if (!string.IsNullOrEmpty(order))
              {
                  executeSql += " ORDER BY " + order;
              }
              return DB.Query<T>(executeSql).ToList();
          }

          /// <summary>
          /// 插入
          /// </summary>
          /// <param name="model"></param>
          /// <returns></returns>
          public int Add(T model)
          {
              string executeSql = @" INSERT INTO " + this.TableName + " (" + string.Join(",", CoulmnsList) + " ) VALUES (" + string.Join(",:", CoulmnsList).Insert(, ":") + ") ";
              return DB.Execute(executeSql, model);
          }

          /// <summary>
          /// 更新
          /// </summary>
          /// <param name="model"></param>
          /// <returns></returns>
          public bool Update(T model)
          {
              var wherePro = model.GetType().GetProperties();
              var whereSql = new List<string>();
              foreach (var item in wherePro)
              {
                  //if (item.GetValue(model) == null) continue;
                  whereSql.Add(string.Format("{0}=:{0}", item.Name));
              }
              string executeSql = @" UPDATE " + this.TableName + " SET  " + string.Join(",", whereSql) + " WHERE " + this.Primarykey + "=:" + Primarykey;
              return DB.Execute(executeSql, model) > ;
          }

          /// <summary>
          /// 根据条件更新指定的字段
          /// </summary>
          /// <param name="updateCoumlns"></param>
          /// <param name="whereStr"></param>
          /// <returns></returns>
          public bool Update(object updateCoumlns, string whereStr)
          {
              var wherePro = updateCoumlns.GetType().GetProperties();
              var whereSql = new List<string>();
              foreach (var item in wherePro)
              {
                  if (item.GetValue(updateCoumlns) == null) continue;
                  whereSql.Add(string.Format("{0}=:{0}", item.Name));
              }
              string executeSql = @" UPDATE " + this.TableName + " SET  " + string.Join(",", whereSql);
              if (!string.IsNullOrEmpty(whereStr))
              {
                  executeSql += " WHERE " + whereStr;
              }
              return DB.Execute(executeSql, updateCoumlns) > ;
          }

          //public bool Update(string[] fields,string value)

          /// <summary>
          /// 获取分页数据
          /// </summary>
          /// <param name="pageIndex"></param>
          /// <param name="pageSize"></param>
          /// <param name="selectFields">查询的字段</param>
          /// <param name="whereObj"></param>
          /// <param name="order"></param>
          /// <returns></returns>
          public PagedList<T> GetPagerList(int pageIndex, int pageSize, string[] selectFields = null, object whereObj = null, string order = null)
          {
              var whereList = new List<string>();
              if (whereObj != null)
              {
                  var wherePro = whereObj.GetType().GetProperties();
                  foreach (var item in wherePro)
                  {
                      if (item.GetValue(whereObj) == null) continue;
                      whereList.Add(string.Format("{0}=:{0}", item.Name));
                  }
              }
              string orderSql = string.Empty, whereSql = string.Empty, fields = " row_.*";
              if (!string.IsNullOrEmpty(order))
              {
                  orderSql = " ORDER BY " + order;
              }
              if (whereList.Count > )
              {
                  whereSql = " WHERE " + string.Join(" and ", whereList);
              }
              if (selectFields != null && selectFields.Length > )
              {
                  fields = string.Join(",", selectFields);
              }
              string executeSql = @" SELECT COUNT(0) FROM  " + this.TableName + whereSql;
              int totalCount = DB.Query<int>(executeSql, whereObj).SingleOrDefault();
              string pagerSql = "SELECT * FROM ( SELECT " + fields + ", rownum rownum_ from ( SELECT * FROM " + this.TableName + whereSql + orderSql + ") row_ where rownum <= " + pageIndex * pageSize + ") where rownum_ >" + (pageIndex - ) * pageSize + "";
              var source = DB.Query<T>(pagerSql, whereObj).ToList();
              return new PagedList<T>(source, pageIndex, pageSize, totalCount);
          }

          /// <summary>
          /// 删除数据
          /// </summary>
          /// <param name="id"></param>
          /// <returns></returns>
          public bool Delete(object id)
          {
              string executeSql = @" DELETE FROM " + this.TableName + " WHERE " + this.Primarykey + " = :ID";
              var conditon = new { ID = id };
              return DB.Execute(executeSql, conditon) > ;
          }

          #region 直接执行sql

          /// <summary>
          /// 执行sql语句，参数都以带入的形式
          /// </summary>
          /// <param name="executeSql"></param>
          /// <param name="value"></param>
          /// <returns></returns>
          public bool Update(string executeSql, object value)
          {
              return DB.Execute(executeSql, value) > ;
          }

          /// <summary>
          /// 执行sql语句，参数都以带入的形式
          /// </summary>
          /// <param name="executeSql"></param>
          /// <param name="value"></param>
          /// <returns></returns>
          public int Add(string executeSql, object value)
          {
              return DB.Execute(executeSql, value);
          }

          /// <summary>
          /// 执行SQL获取table
          /// </summary>
          /// <param name="executeSql"></param>
          /// <returns></returns>
          public DataTable GetTable(string executeSql)
          {
              return DB.Query<DataTable>(executeSql).SingleOrDefault();
          }

          /// <summary>
          /// 执行SQL获取LIST
          /// </summary>
          /// <param name="executeSql"></param>
          /// <returns></returns>
          public List<T> GetList(string executeSql)
          {
              return DB.Query<T>(executeSql).ToList();
          }
          #endregion

          /// <summary>
          /// 对datatable进行分页
          /// </summary>
          /// <param name="dt"></param>
          /// <param name="PageIndex"></param>
          /// <param name="PageSize"></param>
          /// <returns></returns>
          public DataTable SplitDataTable(DataTable dt, int PageIndex, int PageSize)
          {
              if (PageIndex == )
                  return dt;
              DataTable newdt = dt.Clone();
              //newdt.Clear();
              int rowbegin = (PageIndex - ) * PageSize;
              int rowend = PageIndex * PageSize;

              if (rowbegin >= dt.Rows.Count)
                  return newdt;

              if (rowend > dt.Rows.Count)
                  rowend = dt.Rows.Count;
              for (int i = rowbegin; i <= rowend - ; i++)
              {
                  DataRow newdr = newdt.NewRow();
                  DataRow dr = dt.Rows[i];
                  foreach (DataColumn column in dt.Columns)
                  {
                      newdr[column.ColumnName] = dr[column.ColumnName];
                  }
                  newdt.Rows.Add(newdr);
              }

              return newdt;
          }

          /// <summary>
          /// 获取实体所有属性名称
          /// </summary>
          /// <param name="entity"></param>
          /// <returns></returns>
          private List<string> GetEntityProperties(Type type)
          {
              var list = new List<string>();
              PropertyInfo[] properties = type.GetProperties();
              foreach (var pro in properties)
              {
                  var fieldsAttribute = new FieldsAttribute();
                  var attrmodel = pro.GetCustomAttributes<FieldsAttribute>(true).FirstOrDefault();
                  if (attrmodel != null )
                  {//controller上有标记
                      fieldsAttribute = attrmodel as FieldsAttribute;
                  }
                  if (!fieldsAttribute.IsSourceFields) continue;
                 // if ()
                  list.Add(pro.Name);
              }
              return list;
          }
      }
  }