EF 底层基础方法

  1 using System;
  2 using System.Data;
  3 using System.Collections.Generic;
  4 using System.Data.Entity;
  5 using System.Linq;
  6 using System.Linq.Expressions;
  7 using System.Text;
  8 using System.Threading.Tasks;
  9 using SchoolDAL.Context;
 10 using SchoolDAL.Entity;
 11 using System.Data.Entity.Infrastructure;
 12 using System.Data.SqlClient;
 13 using EntityFramework.Extensions;
 14 using System.Reflection;
 15 namespace SchoolDAL
 16 {
 17 
 18     public class BaseDAL
 19     {
 20 
 21         public  DbContext Context;
 22 
 23         public BaseDAL(DbContext context)
 24         {
 25             Context = context;
 26         }
           //得到实体的数量 根据条件
 27         public int GetModelCount<TEntity>(Expression<Func<TEntity, bool>> filterList) where TEntity : class
 28         {
 29             return FindByItem(filterList).Count();
 30         }
 31         //根据单个条件得到实体的集合
 32         public List<TEntity> FindModelList<TEntity>(Expression<Func<TEntity, bool>> filterList,int currPage,int size,out int Total) where TEntity : class
 33         {
 34             List<TEntity> list=new List<TEntity>();
 35             var json = FindByItem(filterList);
 36             try
 37             {
 38                 Total = json.Count();
 39                 list = json.Skip(currPage).Take(size).ToList();// only support order by Id asc
 40             }
 41             catch
 42             {
 43                 Total = 0;
 44             }
 45             return list;
 46         }
 47          //根据条件得到集合
 48         public TEntity FindModel<TEntity>(Expression<Func<TEntity, bool>> filterList) where TEntity : class
 49         {
 50           return   FindByItem(filterList).FirstOrDefault();
 51         }
 52         //根据多个条件得到实体数据源
 53         public IQueryable<TEntity> FindByItem<TEntity>(List<Expression<Func<TEntity, bool>>> filterList) where TEntity : class
 54         {
 55             var json = Context.Set<TEntity>().Where(t => true);
 56             foreach (var item in filterList)
 57             {
 58                 json = json.Where(item);
 59             }
 60             return json;
 61         }
 62          //根据单个条件得到数据源
 63         public IQueryable<TEntity> FindByItem<TEntity>(Expression<Func<TEntity, bool>> filterList) where TEntity : class
 64         {
 65             var json = Context.Set<TEntity>().Where(filterList);
 66 
 67             return json;
 68         }
 69          //单个增加
 70         public bool Create<TEntity>(TEntity TObject) where TEntity : class
 71         {
 72             try
 73             {
 74                 Context.Set<TEntity>().Add(TObject);
 75                 Context.SaveChanges();
 76                 return true;
 77             }
 78             catch (Exception ex)
 79             {
 80                 return false;
 81             }
 82         }
 83         //单个修改
 84         public bool Edit<TEntity>(TEntity TObject) where TEntity : class
 85         {
 86             try
 87             {
 88                 var entry = Context.Entry(TObject);
 89                 Context.Set<TEntity>().Attach(TObject);
 90                 entry.State = EntityState.Modified;
 91                 Context.SaveChanges();
 92                 return true;
 93             }
 94             catch
 95             {
 96                 //throw ex;
 97                 return false;
 98             }
 99         }
100              //单个删除
101         public void Delete<TEntity>(TEntity TObject) where TEntity : class
102         {
103             try
104             {
105                 Context.Set<TEntity>().Remove(TObject);
106                 Context.SaveChanges();
107 
108             }
109             catch (Exception ex)
110             {
111 
112             }
113 
114         }
115 
116          //批量修改
117         public int BulkUpdate<TEntity>(List<Expression<Func<TEntity, bool>>> filterList, Expression<Func<TEntity, TEntity>> UpdatedModel) where TEntity : class
118         {
119             int res = 0;
120             var json = FindByItem(filterList);
121             using (var tran = Context.Database.BeginTransaction())
122             {
123                 try
124                 {
125                     res = Context.Set<TEntity>().Update(json, UpdatedModel);
126                     tran.Commit();
127                 }
128                 catch
129                 {
130                     tran.Rollback();
131                 }
132             }
133             return res;
134         }
135         //批量删除
136         public int BulkDelete<TEntity>(List<Expression<Func<TEntity, bool>>> filterList) where TEntity : class
137         {
138             int res=0;
139             var json = FindByItem(filterList);
140             using(var tran=   Context.Database.BeginTransaction())
141             {
142                 try
143                 {
144                    res= Context.Set<TEntity>().Delete(json);
145                     tran.Commit();
146                 }
147                 catch
148                 {
149                 tran.Rollback();
150                 }
151             }
152             return res;
153 
154         }
155           //批量创建
156         public void BulkCreate<TEntity>(List<TEntity> list,string tableName) where TEntity : class
157         {
158 
159             DataTable dt = new DataTable();
160             Type type = typeof(TEntity);
161             PropertyInfo[] propes = type.GetProperties();
162             foreach (var prop in propes)
163             {
164                 dt.Columns.Add(prop.Name);
165             }
166             foreach (var entity in list)
167             {
168                 DataRow row = dt.NewRow();
169                 foreach (DataColumn col in dt.Columns)
170                 {
171                     foreach (var prop in propes)
172                     {
173                         if (!col.ColumnName.Equals("id", StringComparison.InvariantCultureIgnoreCase))
174                         {
175                             if (prop.Name.Equals(col.ColumnName, StringComparison.InvariantCultureIgnoreCase))
176                                 row[col.ColumnName] = prop.GetValue(entity);
177                         }
178                     }
179 
180                 }
181                 dt.Rows.Add(row);
182             }
183             if (dt != null && dt.Rows.Count > 0)
184             {
185                 using (var tran = Context.BeginTransaction())
186                 {
187                     try
188                     {
189                         using (SqlBulkCopy sqlBulkCopy = new SqlBulkCopy(Context.Database.Connection.ConnectionString))
190                         {
191                             sqlBulkCopy.BatchSize = 10000;
192                             sqlBulkCopy.BulkCopyTimeout = 12000;
193                             sqlBulkCopy.DestinationTableName = string.Format("dbo.{0}", tableName);
196                                 for (int i = 1; i < dt.Columns.Count; i++)
197                                 {
198                                     sqlBulkCopy.ColumnMappings.Add(i, i);
199                                 }
201                             sqlBulkCopy.WriteToServer(dt);
202                             tran.Commit();
203                         }
204                     }
205                     catch (Exception e)
206                     {
207                         tran.Rollback();
208                     }
209                 }
210 
211             }
212            
213         }
214           
215         public SchoolContext GetContext()
216         {
217             return new SchoolContext();
218         }
219 
220         public void DisposeContext(SchoolContext db)
221         {
222                 if (db != null)
223                     db.Dispose();
224         }
225         //绑定实体
226         public DbEntityEntry<TEntity> EditEntry<TEntity>(TEntity TObject) where TEntity : class
227         {
228             var entry = Context.Entry(TObject);
229             Context.Set<TEntity>().Attach(TObject);
230             entry.State = EntityState.Modified;
231             return entry;
232         }
233              //执行存储过程
234         public List<TEntity> ExecuteByStoreProcedure<TEntity>(string ExecuteProcedure,SqlParameter[] parms) where TEntity : class
235         {
236             List<SqlParameter> parmList = new List<SqlParameter>();
237 
245             var list = Context.Database.SqlQuery<TEntity>(ExecuteProcedure, parms);
246                 var enityList = list.ToList();
247              
248                 return enityList;
249          
250         }
251 
252     }
253 }

　　

上面方法包括常见的增删改查，多条件查询，批量删除和修改，以及对存储过程的支持。其中BulkDelete 和BulkUpdate 依赖于EntityFramework.Extensions的类库，这个类库必须通过Nuget安装 链接地址：https://www.nuget.org/packages/EntityFramework.Extended 注意你的Ef版本。