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本章我们来创建仓储类Repository 并且引入 UnitOfWork
UnitOfWork 工作单元，对于这个的解释和实例，网上很多很多大神之作，我在这就不班门弄斧了，只是浅谈 一下个人理解，不一定对，希望大家指正：
UnitOfWork 看了很多，个人理解就是 统一事务，在很多操作中我们可能是进行多项操作的，比如 同时保存两个表的数据，如果我们先保存一个表（SaveChanges()之后），再保存另一个表（SaveChanges()）其实是两个不同的事务，通俗的讲，我们对数据库提交了两次数据。而UnitOfWork 就是 把本次操作（分别保存两张表）放在统一事务中，所有的CRUD完成后，统一提交数据，即保证数据的一致性，又减少了提交次数，提高性能。
举个例子，我们之前的Repository的保存操作：
Repository:
public virtual bool Save(T entity)
{
_Context.Add(entity);
return _Context.SaveChanges() > 0;
}
Controller:
public ActionResult Save()
{
var Users=new Users(){Id=1,UserName="张三"};
var Logs=new Logs(){log="注册了用户张三"};
_UserService.Save(Users);
_LogService.Save(Logs);
}
因为本身EF就是带事务的，但是_Context.SaveChanges()之后，事务就结束了，也提交了数据。所以，上面的例子 应该是开启了两次事务，提交了两次数据（一次是Users 一次是 Logs）
这显然是不合理的，首先不说提交两次数据性能的问题，如果用户注册失败，那么日志也不应该添加，应该回滚。但是，显然，上面没有这么做。
所以有了UnitOfWork。
使用UnitOfWork之后，代码应该是这样的：
UnitOfWork:
public bool Commit()
{
return _Context.SaveChanges() > 0;
}
Repository:
public virtual bool Save(T entity)
{
_Context.Add(entity);
}
Controller:
public ActionResult Save()
{
var Users=new Users(){Id=1,UserName="张三"};
var Logs=new Logs(){log="注册了用户张三"};
_UserService.Save(Users);
_LogService.Save(Logs);
_UnitOfWork.Commit();
}
我们在wkmvc.Core类库下，新建一个接口 IUnitOfWork：
1 namespace wkmvc.Core
2 {
3 /// <summary>
4 /// Describe：工作单元接口
5 /// Author：yuangang
6 /// Date：2016/07/16
7 /// Blogs:http://www.cnblogs.com/yuangang
8 /// </summary>
9 public interface IUnitOfWork
10 {
11 bool Commit();
12 }
13 }
IUnitOfWork 实现类 UnitOfWork：
1 using System;
2 using wkmvc.Data;
3
4 namespace wkmvc.Core
5 {
6 /// <summary>
7 /// Describe：工作单元实现类
8 /// Author：yuangang
9 /// Date：2016/07/16
10 /// Blogs:http://www.cnblogs.com/yuangang
11 /// </summary>
12 public class UnitOfWork : IUnitOfWork, IDisposable
13 {
14 #region 数据上下文
15
16 /// <summary>
17 /// 数据上下文
18 /// </summary>
19 private ApplicationDbContext _Context;
20 public UnitOfWork(ApplicationDbContext Context)
21 {
22 _Context = Context;
23 }
24
25 #endregion
26
27 public bool Commit()
28 {
29 return _Context.SaveChanges() > 0;
30 }
31
32 public void Dispose()
33 {
34 if(_Context!=null)
35 {
36 _Context.Dispose();
37 }
38 GC.SuppressFinalize(this);
39 }
40 }
41 }
这样，UnitOfWork 就完成了。下面我们来添加仓储：
新建接口 IRepository 添加基本的操作方法：
1 using System;
2 using System.Linq.Expressions;
3
4 namespace wkmvc.Core
5 {
6 /// <summary>
7 /// Describe：仓储接口
8 /// Author：yuangang
9 /// Date：2016/07/16
10 /// Blogs:http://www.cnblogs.com/yuangang
11 /// </summary>
12 /// <typeparam name="T">实体模型</typeparam>
13 public interface IRepository<T> where T : class
14 {
15 #region 单模型 CRUD 操作
16
17 /// <summary>
18 /// 增加一条记录
19 /// </summary>
20 /// <param name="entity">实体模型</param>
21 /// <param name="IsCommit">是否提交（默认提交）</param>
22 /// <returns></returns>
23 bool Save(T entity, bool IsCommit = true);
24
25 /// <summary>
26 /// 更新一条记录
27 /// </summary>
28 /// <param name="entity">实体模型</param>
29 /// <param name="IsCommit">是否提交（默认提交）</param>
30 /// <returns></returns>
31 bool Update(T entity, bool IsCommit = true);
32
33 /// <summary>
34 /// 增加或更新一条记录
35 /// </summary>
36 /// <param name="entity">实体模型</param>
37 /// <param name="IsSave">是否增加</param>
38 /// <param name="IsCommit">是否提交（默认提交）</param>
39 /// <returns></returns>
40 bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true);
41
42 /// <summary>
43 /// 通过Lamda表达式获取实体
44 /// </summary>
45 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
46 /// <returns></returns>
47 T Get(Expression<Func<T, bool>> predicate);
48
49 /// <summary>
50 /// 删除一条记录
51 /// </summary>
52 /// <param name="entity">实体模型</param>
53 /// <param name="IsCommit">是否提交（默认提交）</param>
54 /// <returns></returns>
55 bool Delete(T entity, bool IsCommit = true);
56
57 #endregion
58 }
59 }
实现类 Repository :
1 using Microsoft.EntityFrameworkCore;
2 using System;
3 using System.Linq;
4 using System.Linq.Expressions;
5 using wkmvc.Data;
6
7 namespace wkmvc.Core
8 {
9 /// <summary>
10 /// Describe：仓储实现类
11 /// Author：yuangang
12 /// Date：2016/07/16
13 /// Blogs:http://www.cnblogs.com/yuangang
14 /// </summary>
15 /// <typeparam name="T">实体模型</typeparam>
16 public abstract class Repository<T> : IRepository<T> where T : class
17 {
18 #region 数据上下文
19
20 /// <summary>
21 /// 数据上下文
22 /// </summary>
23 private ApplicationDbContext _Context;
24
25 /// <summary>
26 /// 工作单元
27 /// </summary>
28 UnitOfWork _UnitOfWork;
29
30 public Repository(ApplicationDbContext Context)
31 {
32 _Context = Context;
33 _UnitOfWork = new UnitOfWork(_Context);
34 }
35
36
37 #endregion
38
39 #region 单模型 CRUD 操作
40
41 /// <summary>
42 /// 增加一条记录
43 /// </summary>
44 /// <param name="entity">实体模型</param>
45 /// <param name="IsCommit">是否提交（默认提交）</param>
46 /// <returns></returns>
47 public virtual bool Save(T entity,bool IsCommit=true)
48 {
49 _Context.Add(entity);
50 if (IsCommit)
51 return _UnitOfWork.Commit();
52 else
53 return false;
54 }
55
56 /// <summary>
57 /// 更新一条记录
58 /// </summary>
59 /// <param name="entity">实体模型</param>
60 /// <param name="IsCommit">是否提交（默认提交）</param>
61 /// <returns></returns>
62 public virtual bool Update(T entity, bool IsCommit = true)
63 {
64 _Context.Attach(entity);
65 _Context.Entry(entity).State = EntityState.Modified;
66 if (IsCommit)
67 return _UnitOfWork.Commit();
68 else
69 return false;
70 }
71
72 /// <summary>
73 /// 增加或更新一条记录
74 /// </summary>
75 /// <param name="entity">实体模型</param>
76 /// <param name="IsSave">是否增加</param>
77 /// <param name="IsCommit">是否提交（默认提交）</param>
78 /// <returns></returns>
79 public virtual bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true)
80 {
81 return IsSave ? Save(entity, IsCommit) : Update(entity, IsCommit);
82 }
83
84 /// <summary>
85 /// 通过Lamda表达式获取实体
86 /// </summary>
87 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
88 /// <returns></returns>
89 public virtual T Get(Expression<Func<T, bool>> predicate)
90 {
91 return _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate);
92 }
93
94
95 /// <summary>
96 /// 删除一条记录
97 /// </summary>
98 /// <param name="entity">实体模型</param>
99 /// <param name="IsCommit">是否提交（默认提交）</param>
100 /// <returns></returns>
101 public virtual bool Delete(T entity, bool IsCommit = true)
102 {
103 if (entity == null) return false;
104 _Context.Remove(entity);
105
106 if (IsCommit)
107 return _UnitOfWork.Commit();
108 else
109 return false;
110 }
111
112 #endregion
113
114
115 }
116 }
我们都添加了一个 bool IsCommit = true 参数，是为了方便，如果仅仅是进行一项操作，那就没必要使用 UnitOfWork 统一 直接 SaveChanages() 就行了
我们来看下使用：
//第一种
public bool TestOne()
{
var users = new SYS_USER() { UserName="张三",Account="zhangsan",Password="123456" };
return _UserService.Save(users);
}
//第二种
public bool TestTwo()
{
var users1 = new SYS_USER() { UserName = "张三", Account = "zhangsan", Password = "123456" };
var users2 = new SYS_USER() { UserName = "李四", Account = "lisi", Password = "456789" };
var users3 = new SYS_USER() { UserName = "王五", Account = "wangwu", Password = "321654" };
_UserService.Save(users1);
_UserService.Save(users2);
_UserService.Save(users3);
return _UnitOfWork.Commit();
}
本篇主要是介绍用法，具体的解释清大家参考大神们的讲解，如有不对的地方希望指正。具体的实现代码，我们后面一起一点一点写。
1 public interface IRepository<T> where T : class
2 {
3 #region 单模型 CRUD 操作
4
5 /// <summary>
6 /// 增加一条记录
7 /// </summary>
8 /// <param name="entity">实体模型</param>
9 /// <param name="IsCommit">是否提交（默认提交）</param>
10 /// <returns></returns>
11 bool Save(T entity, bool IsCommit = true);
12 /// <summary>
13 /// 增加一条记录（异步方式）
14 /// </summary>
15 /// <param name="entity">实体模型</param>
16 /// <param name="IsCommit">是否提交（默认提交）</param>
17 /// <returns></returns>
18 Task<bool> SaveAsync(T entity, bool IsCommit = true);
19
20 /// <summary>
21 /// 更新一条记录
22 /// </summary>
23 /// <param name="entity">实体模型</param>
24 /// <param name="IsCommit">是否提交（默认提交）</param>
25 /// <returns></returns>
26 bool Update(T entity, bool IsCommit = true);
27 /// <summary>
28 /// 更新一条记录（异步方式）
29 /// </summary>
30 /// <param name="entity">实体模型</param>
31 /// <param name="IsCommit">是否提交（默认提交）</param>
32 /// <returns></returns>
33 Task<bool> UpdateAsync(T entity, bool IsCommit = true);
34
35 /// <summary>
36 /// 增加或更新一条记录
37 /// </summary>
38 /// <param name="entity">实体模型</param>
39 /// <param name="IsSave">是否增加</param>
40 /// <param name="IsCommit">是否提交（默认提交）</param>
41 /// <returns></returns>
42 bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true);
43 /// <summary>
44 /// 增加或更新一条记录（异步方式）
45 /// </summary>
46 /// <param name="entity">实体模型</param>
47 /// <param name="IsSave">是否增加</param>
48 /// <param name="IsCommit">是否提交（默认提交）</param>
49 /// <returns></returns>
50 Task<bool> SaveOrUpdateAsync(T entity, bool IsSave, bool IsCommit = true);
51
52 /// <summary>
53 /// 通过Lamda表达式获取实体
54 /// </summary>
55 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
56 /// <returns></returns>
57 T Get(Expression<Func<T, bool>> predicate);
58 /// <summary>
59 /// 通过Lamda表达式获取实体（异步方式）
60 /// </summary>
61 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
62 /// <returns></returns>
63 Task<T> GetAsync(Expression<Func<T, bool>> predicate);
64
65 /// <summary>
66 /// 删除一条记录
67 /// </summary>
68 /// <param name="entity">实体模型</param>
69 /// <param name="IsCommit">是否提交（默认提交）</param>
70 /// <returns></returns>
71 bool Delete(T entity, bool IsCommit = true);
72 /// <summary>
73 /// 删除一条记录（异步方式）
74 /// </summary>
75 /// <param name="entity">实体模型</param>
76 /// <param name="IsCommit">是否提交（默认提交）</param>
77 /// <returns></returns>
78 Task<bool> DeleteAsync(T entity, bool IsCommit = true);
79
80 #endregion
81
82 #region 多模型 操作
83
84 /// <summary>
85 /// 增加多条记录，同一模型
86 /// </summary>
87 /// <param name="T1">实体模型集合</param>
88 /// <param name="IsCommit">是否提交（默认提交）</param>
89 /// <returns></returns>
90 bool SaveList(List<T> T1, bool IsCommit = true);
91 /// <summary>
92 /// 增加多条记录，同一模型（异步方式）
93 /// </summary>
94 /// <param name="T1">实体模型集合</param>
95 /// <param name="IsCommit">是否提交（默认提交）</param>
96 /// <returns></returns>
97 Task<bool> SaveListAsync(List<T> T1, bool IsCommit = true);
98
99 /// <summary>
100 /// 增加多条记录，独立模型
101 /// </summary>
102 /// <param name="T1">实体模型集合</param>
103 /// <param name="IsCommit">是否提交（默认提交）</param>
104 /// <returns></returns>
105 bool SaveList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
106 /// <summary>
107 /// 增加多条记录，独立模型（异步方式）
108 /// </summary>
109 /// <param name="T1">实体模型集合</param>
110 /// <param name="IsCommit">是否提交（默认提交）</param>
111 /// <returns></returns>
112 Task<bool> SaveListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
113
114 /// <summary>
115 /// 更新多条记录，同一模型
116 /// </summary>
117 /// <param name="T1">实体模型集合</param>
118 /// <param name="IsCommit">是否提交（默认提交）</param>
119 /// <returns></returns>
120 bool UpdateList(List<T> T1, bool IsCommit = true);
121 /// <summary>
122 /// 更新多条记录，同一模型（异步方式）
123 /// </summary>
124 /// <param name="T1">实体模型集合</param>
125 /// <param name="IsCommit">是否提交（默认提交）</param>
126 /// <returns></returns>
127 Task<bool> UpdateListAsync(List<T> T1, bool IsCommit = true);
128
129 /// <summary>
130 /// 更新多条记录，独立模型
131 /// </summary>
132 /// <param name="T1">实体模型集合</param>
133 /// <param name="IsCommit">是否提交（默认提交）</param>
134 /// <returns></returns>
135 bool UpdateList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
136 /// <summary>
137 /// 更新多条记录，独立模型（异步方式）
138 /// </summary>
139 /// <param name="T1">实体模型集合</param>
140 /// <param name="IsCommit">是否提交（默认提交）</param>
141 /// <returns></returns>
142 Task<bool> UpdateListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
143
144 /// <summary>
145 /// 删除多条记录，同一模型
146 /// </summary>
147 /// <param name="T1">实体模型集合</param>
148 /// <param name="IsCommit">是否提交（默认提交）</param>
149 /// <returns></returns>
150 bool DeleteList(List<T> T1, bool IsCommit = true);
151 /// <summary>
152 /// 删除多条记录，同一模型（异步方式）
153 /// </summary>
154 /// <param name="T1">实体模型集合</param>
155 /// <param name="IsCommit">是否提交（默认提交）</param>
156 /// <returns></returns>
157 Task<bool> DeleteListAsync(List<T> T1, bool IsCommit = true);
158
159 /// <summary>
160 /// 删除多条记录，独立模型
161 /// </summary>
162 /// <param name="T1">实体模型集合</param>
163 /// <param name="IsCommit">是否提交（默认提交）</param>
164 /// <returns></returns>
165 bool DeleteList<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
166 /// <summary>
167 /// 删除多条记录，独立模型（异步方式）
168 /// </summary>
169 /// <param name="T1">实体模型集合</param>
170 /// <param name="IsCommit">是否提交（默认提交）</param>
171 /// <returns></returns>
172 Task<bool> DeleteListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class;
173
174 /// <summary>
175 /// 通过Lamda表达式，删除一条或多条记录
176 /// </summary>
177 /// <param name="predicate"></param>
178 /// <param name="IsCommit"></param>
179 /// <returns></returns>
180 bool Delete(Expression<Func<T, bool>> predicate, bool IsCommit = true);
181 /// <summary>
182 /// 通过Lamda表达式，删除一条或多条记录（异步方式）
183 /// </summary>
184 /// <param name="predicate"></param>
185 /// <param name="IsCommit"></param>
186 /// <returns></returns>
187 Task<bool> DeleteAsync(Expression<Func<T, bool>> predicate, bool IsCommit = true);
188
189 #endregion
190
191 #region 获取多条数据操作
192
193 /// <summary>
194 /// 返回IQueryable集合，延时加载数据
195 /// </summary>
196 /// <param name="predicate"></param>
197 /// <returns></returns>
198 IQueryable<T> LoadAll(Expression<Func<T, bool>> predicate);
199 /// <summary>
200 /// 返回IQueryable集合，延时加载数据（异步方式）
201 /// </summary>
202 /// <param name="predicate"></param>
203 /// <returns></returns>
204 Task<IQueryable<T>> LoadAllAsync(Expression<Func<T, bool>> predicate);
205
206 // <summary>
207 /// 返回List<T>集合,不采用延时加载
208 /// </summary>
209 /// <param name="predicate"></param>
210 /// <returns></returns>
211 List<T> LoadListAll(Expression<Func<T, bool>> predicate);
212 // <summary>
213 /// 返回List<T>集合,不采用延时加载（异步方式）
214 /// </summary>
215 /// <param name="predicate"></param>
216 /// <returns></returns>
217 Task<List<T>> LoadListAllAsync(Expression<Func<T, bool>> predicate);
218
219 /// <summary>
220 /// T-Sql方式：返回IQueryable<T>集合
221 /// </summary>
222 /// <param name="sql">SQL语句</param>
223 /// <param name="para">Parameters参数</param>
224 /// <returns></returns>
225 IQueryable<T> LoadAllBySql(string sql, params DbParameter[] para);
226 /// <summary>
227 /// T-Sql方式：返回IQueryable<T>集合（异步方式）
228 /// </summary>
229 /// <param name="sql">SQL语句</param>
230 /// <param name="para">Parameters参数</param>
231 /// <returns></returns>
232 Task<IQueryable<T>> LoadAllBySqlAsync(string sql, params DbParameter[] para);
233
234 /// <summary>
235 /// T-Sql方式：返回List<T>集合
236 /// </summary>
237 /// <param name="sql">SQL语句</param>
238 /// <param name="para">Parameters参数</param>
239 /// <returns></returns>
240 List<T> LoadListAllBySql(string sql, params DbParameter[] para);
241 /// <summary>
242 /// T-Sql方式：返回List<T>集合（异步方式）
243 /// </summary>
244 /// <param name="sql">SQL语句</param>
245 /// <param name="para">Parameters参数</param>
246 /// <returns></returns>
247 Task<List<T>> LoadListAllBySqlAsync(string sql, params DbParameter[] para);
248
249 /// <summary>
250 /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合
251 /// </summary>
252 /// <typeparam name="TEntity">实体对象</typeparam>
253 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
254 /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
255 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
256 /// <param name="orderby">排序字段</param>
257 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
258 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
259 /// <returns>实体集合</returns>
260 List<TResult> QueryEntity<TEntity, TOrderBy, TResult>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby,Expression<Func<TEntity, TResult>> selector,bool IsAsc)
261 where TEntity : class
262 where TResult : class;
263 /// <summary>
264 /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合（异步方式）
265 /// </summary>
266 /// <typeparam name="TEntity">实体对象</typeparam>
267 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
268 /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
269 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
270 /// <param name="orderby">排序字段</param>
271 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
272 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
273 /// <returns>实体集合</returns>
274 Task<List<TResult>> QueryEntityAsync<TEntity, TOrderBy, TResult>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Expression<Func<TEntity, TResult>> selector, bool IsAsc)
275 where TEntity : class
276 where TResult : class;
277
278 /// <summary>
279 /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合
280 /// </summary>
281 /// <typeparam name="TEntity">实体对象</typeparam>
282 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
283 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
284 /// <param name="orderby">排序字段</param>
285 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
286 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
287 /// <returns>自定义实体集合</returns>
288 List<object> QueryObject<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby,Func<IQueryable<TEntity>,List<object>> selector,bool IsAsc)
289 where TEntity : class;
290 /// <summary>
291 /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合（异步方式）
292 /// </summary>
293 /// <typeparam name="TEntity">实体对象</typeparam>
294 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
295 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
296 /// <param name="orderby">排序字段</param>
297 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
298 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
299 /// <returns>自定义实体集合</returns>
300 Task<List<object>> QueryObjectAsync<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>, List<object>> selector, bool IsAsc)
301 where TEntity : class;
302
303 /// <summary>
304 /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合
305 /// </summary>
306 /// <typeparam name="TEntity">实体对象</typeparam>
307 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
308 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
309 /// <param name="orderby">排序字段</param>
310 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
311 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
312 /// <returns>动态类</returns>
313 dynamic QueryDynamic<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where,Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>,List<object>> selector,bool IsAsc)
314 where TEntity : class;
315 /// <summary>
316 /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合（异步方式）
317 /// </summary>
318 /// <typeparam name="TEntity">实体对象</typeparam>
319 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
320 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
321 /// <param name="orderby">排序字段</param>
322 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
323 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
324 /// <returns>动态类</returns>
325 Task<dynamic> QueryDynamicAsync<TEntity, TOrderBy>(Expression<Func<TEntity, bool>> where, Expression<Func<TEntity, TOrderBy>> orderby, Func<IQueryable<TEntity>, List<object>> selector, bool IsAsc)
326 where TEntity : class;
327
328 #endregion
329
330 #region 验证是否存在
331
332 /// <summary>
333 /// 验证当前条件是否存在相同项
334 /// </summary>
335 bool IsExist(Expression<Func<T, bool>> predicate);
336 /// <summary>
337 /// 验证当前条件是否存在相同项（异步方式）
338 /// </summary>
339 Task<bool> IsExistAsync(Expression<Func<T, bool>> predicate);
340
341 /// <summary>
342 /// 根据SQL验证实体对象是否存在
343 /// </summary>
344 bool IsExist(string sql, params DbParameter[] para);
345 /// <summary>
346 /// 根据SQL验证实体对象是否存在（异步方式）
347 /// </summary>
348 Task<bool> IsExistAsync(string sql, params DbParameter[] para);
349
350 #endregion
351 }
1 public abstract class Repository<T> : IRepository<T> where T : class
2 {
3 #region 数据上下文
4
5 /// <summary>
6 /// 数据上下文
7 /// </summary>
8 private ApplicationDbContext _Context;
9
10 public Repository(ApplicationDbContext Context)
11 {
12 _Context = Context;
13 }
14
15 #endregion
16
17 #region 单模型 CRUD 操作
18
19 /// <summary>
20 /// 增加一条记录
21 /// </summary>
22 /// <param name="entity">实体模型</param>
23 /// <param name="IsCommit">是否提交（默认提交）</param>
24 /// <returns></returns>
25 public virtual bool Save(T entity,bool IsCommit=true)
26 {
27 _Context.Set<T>().Add(entity);
28 if (IsCommit)
29 return _Context.SaveChanges() > 0;
30 else
31 return false;
32 }
33 /// <summary>
34 /// 增加一条记录(异步方式)
35 /// </summary>
36 /// <param name="entity">实体模型</param>
37 /// <param name="IsCommit">是否提交（默认提交）</param>
38 /// <returns></returns>
39 public virtual async Task<bool> SaveAsync(T entity, bool IsCommit = true)
40 {
41 _Context.Set<T>().Add(entity);
42 if (IsCommit)
43 return await Task.Run(() => _Context.SaveChanges() > 0);
44 else
45 return await Task.Run(() => false);
46 }
47
48 /// <summary>
49 /// 更新一条记录
50 /// </summary>
51 /// <param name="entity">实体模型</param>
52 /// <param name="IsCommit">是否提交（默认提交）</param>
53 /// <returns></returns>
54 public virtual bool Update(T entity, bool IsCommit = true)
55 {
56 _Context.Set<T>().Attach(entity);
57 _Context.Entry<T>(entity).State = EntityState.Modified;
58 if (IsCommit)
59 return _Context.SaveChanges() > 0;
60 else
61 return false;
62 }
63 /// <summary>
64 /// 更新一条记录（异步方式）
65 /// </summary>
66 /// <param name="entity">实体模型</param>
67 /// <param name="IsCommit">是否提交（默认提交）</param>
68 /// <returns></returns>
69 public virtual async Task<bool> UpdateAsync(T entity, bool IsCommit = true)
70 {
71 _Context.Set<T>().Attach(entity);
72 _Context.Entry<T>(entity).State = EntityState.Modified;
73 if (IsCommit)
74 return await Task.Run(() => _Context.SaveChanges() > 0);
75 else
76 return await Task.Run(() => false);
77 }
78
79 /// <summary>
80 /// 增加或更新一条记录
81 /// </summary>
82 /// <param name="entity">实体模型</param>
83 /// <param name="IsSave">是否增加</param>
84 /// <param name="IsCommit">是否提交（默认提交）</param>
85 /// <returns></returns>
86 public virtual bool SaveOrUpdate(T entity, bool IsSave, bool IsCommit = true)
87 {
88 return IsSave ? Save(entity, IsCommit) : Update(entity, IsCommit);
89 }
90 /// <summary>
91 /// 增加或更新一条记录（异步方式）
92 /// </summary>
93 /// <param name="entity">实体模型</param>
94 /// <param name="IsSave">是否增加</param>
95 /// <param name="IsCommit">是否提交（默认提交）</param>
96 /// <returns></returns>
97 public virtual async Task<bool> SaveOrUpdateAsync(T entity, bool IsSave, bool IsCommit = true)
98 {
99 return IsSave ? await SaveAsync(entity, IsCommit) : await UpdateAsync(entity, IsCommit);
100 }
101
102 /// <summary>
103 /// 通过Lamda表达式获取实体
104 /// </summary>
105 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
106 /// <returns></returns>
107 public virtual T Get(Expression<Func<T, bool>> predicate)
108 {
109 return _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate);
110 }
111 /// <summary>
112 /// 通过Lamda表达式获取实体（异步方式）
113 /// </summary>
114 /// <param name="predicate">Lamda表达式（p=>p.Id==Id）</param>
115 /// <returns></returns>
116 public virtual async Task<T> GetAsync(Expression<Func<T, bool>> predicate)
117 {
118 return await Task.Run(()=> _Context.Set<T>().AsNoTracking().SingleOrDefault(predicate));
119 }
120
121 /// <summary>
122 /// 删除一条记录
123 /// </summary>
124 /// <param name="entity">实体模型</param>
125 /// <param name="IsCommit">是否提交（默认提交）</param>
126 /// <returns></returns>
127 public virtual bool Delete(T entity, bool IsCommit = true)
128 {
129 if (entity == null) return false;
130 _Context.Set<T>().Attach(entity);
131 _Context.Set<T>().Remove(entity);
132
133 if (IsCommit)
134 return _Context.SaveChanges() > 0;
135 else
136 return false;
137 }
138 /// <summary>
139 /// 删除一条记录（异步方式）
140 /// </summary>
141 /// <param name="entity">实体模型</param>
142 /// <param name="IsCommit">是否提交（默认提交）</param>
143 /// <returns></returns>
144 public virtual async Task<bool> DeleteAsync(T entity, bool IsCommit = true)
145 {
146 if (entity == null) return await Task.Run(() => false);
147 _Context.Set<T>().Attach(entity);
148 _Context.Set<T>().Remove(entity);
149 if (IsCommit)
150 return await Task.Run(() => _Context.SaveChanges() > 0);
151 else
152 return await Task.Run(() => false); ;
153 }
154
155 #endregion
156
157 #region 多模型 操作
158
159 /// <summary>
160 /// 增加多条记录，同一模型
161 /// </summary>
162 /// <param name="T1">实体模型集合</param>
163 /// <param name="IsCommit">是否提交（默认提交）</param>
164 /// <returns></returns>
165 public virtual bool SaveList(List<T> T1, bool IsCommit = true)
166 {
167 if (T1 == null || T1.Count == 0) return false;
168
169 T1.ToList().ForEach(item =>
170 {
171 _Context.Set<T>().Add(item);
172 });
173
174 if (IsCommit)
175 return _Context.SaveChanges() > 0;
176 else
177 return false;
178 }
179 /// <summary>
180 /// 增加多条记录，同一模型（异步方式）
181 /// </summary>
182 /// <param name="T1">实体模型集合</param>
183 /// <param name="IsCommit">是否提交（默认提交）</param>
184 /// <returns></returns>
185 public virtual async Task<bool> SaveListAsync(List<T> T1, bool IsCommit = true)
186 {
187 if (T1 == null || T1.Count == 0) return await Task.Run(() => false);
188
189 T1.ToList().ForEach(item =>
190 {
191 _Context.Set<T>().Add(item);
192 });
193
194 if (IsCommit)
195 return await Task.Run(() => _Context.SaveChanges() > 0);
196 else
197 return await Task.Run(() => false);
198 }
199
200 /// <summary>
201 /// 增加多条记录，独立模型
202 /// </summary>
203 /// <param name="T1">实体模型集合</param>
204 /// <param name="IsCommit">是否提交（默认提交）</param>
205 /// <returns></returns>
206 public virtual bool SaveList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
207 {
208 if (T == null || T.Count == 0) return false;
209 var tmp = _Context.ChangeTracker.Entries<T>().ToList();
210 foreach (var x in tmp)
211 {
212 var properties = typeof(T).GetTypeInfo().GetProperties();
213 foreach (var y in properties)
214 {
215 var entry = x.Property(y.Name);
216 entry.CurrentValue = entry.OriginalValue;
217 entry.IsModified = false;
218 y.SetValue(x.Entity, entry.OriginalValue);
219 }
220 x.State = EntityState.Unchanged;
221 }
222 T.ToList().ForEach(item =>
223 {
224 _Context.Set<T1>().Add(item);
225 });
226 if (IsCommit)
227 return _Context.SaveChanges() > 0;
228 else
229 return false;
230 }
231 /// <summary>
232 /// 增加多条记录，独立模型（异步方式）
233 /// </summary>
234 /// <param name="T1">实体模型集合</param>
235 /// <param name="IsCommit">是否提交（默认提交）</param>
236 /// <returns></returns>
237 public virtual async Task<bool> SaveListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
238 {
239 if (T == null || T.Count == 0) return await Task.Run(() => false);
240 var tmp = _Context.ChangeTracker.Entries<T>().ToList();
241 foreach (var x in tmp)
242 {
243 var properties = typeof(T).GetTypeInfo().GetProperties();
244 foreach (var y in properties)
245 {
246 var entry = x.Property(y.Name);
247 entry.CurrentValue = entry.OriginalValue;
248 entry.IsModified = false;
249 y.SetValue(x.Entity, entry.OriginalValue);
250 }
251 x.State = EntityState.Unchanged;
252 }
253 T.ToList().ForEach(item =>
254 {
255 _Context.Set<T1>().Add(item);
256 });
257 if (IsCommit)
258 return await Task.Run(() => _Context.SaveChanges() > 0);
259 else
260 return await Task.Run(() => false);
261 }
262
263 /// <summary>
264 /// 更新多条记录，同一模型
265 /// </summary>
266 /// <param name="T1">实体模型集合</param>
267 /// <param name="IsCommit">是否提交（默认提交）</param>
268 /// <returns></returns>
269 public virtual bool UpdateList(List<T> T1, bool IsCommit = true)
270 {
271 if (T1 == null || T1.Count == 0) return false;
272
273 T1.ToList().ForEach(item =>
274 {
275 _Context.Set<T>().Attach(item);
276 _Context.Entry<T>(item).State = EntityState.Modified;
277 });
278
279 if (IsCommit)
280 return _Context.SaveChanges() > 0;
281 else
282 return false;
283 }
284 /// <summary>
285 /// 更新多条记录，同一模型（异步方式）
286 /// </summary>
287 /// <param name="T1">实体模型集合</param>
288 /// <param name="IsCommit">是否提交（默认提交）</param>
289 /// <returns></returns>
290 public virtual async Task<bool> UpdateListAsync(List<T> T1, bool IsCommit = true)
291 {
292 if (T1 == null || T1.Count == 0) return await Task.Run(() => false);
293
294 T1.ToList().ForEach(item =>
295 {
296 _Context.Set<T>().Attach(item);
297 _Context.Entry<T>(item).State = EntityState.Modified;
298 });
299
300 if (IsCommit)
301 return await Task.Run(() => _Context.SaveChanges() > 0);
302 else
303 return await Task.Run(() => false);
304 }
305
306 /// <summary>
307 /// 更新多条记录，独立模型
308 /// </summary>
309 /// <param name="T1">实体模型集合</param>
310 /// <param name="IsCommit">是否提交（默认提交）</param>
311 /// <returns></returns>
312 public virtual bool UpdateList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
313 {
314 if (T == null || T.Count == 0) return false;
315
316 T.ToList().ForEach(item =>
317 {
318 _Context.Set<T1>().Attach(item);
319 _Context.Entry<T1>(item).State = EntityState.Modified;
320 });
321
322 if (IsCommit)
323 return _Context.SaveChanges() > 0;
324 else
325 return false;
326 }
327 /// <summary>
328 /// 更新多条记录，独立模型（异步方式）
329 /// </summary>
330 /// <param name="T1">实体模型集合</param>
331 /// <param name="IsCommit">是否提交（默认提交）</param>
332 /// <returns></returns>
333 public virtual async Task<bool> UpdateListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
334 {
335 if (T == null || T.Count == 0) return await Task.Run(() => false);
336
337 T.ToList().ForEach(item =>
338 {
339 _Context.Set<T1>().Attach(item);
340 _Context.Entry<T1>(item).State = EntityState.Modified;
341 });
342
343 if (IsCommit)
344 return await Task.Run(() => _Context.SaveChanges() > 0);
345 else
346 return await Task.Run(() => false);
347 }
348
349 /// <summary>
350 /// 删除多条记录，同一模型
351 /// </summary>
352 /// <param name="T1">实体模型集合</param>
353 /// <param name="IsCommit">是否提交（默认提交）</param>
354 /// <returns></returns>
355 public virtual bool DeleteList(List<T> T1, bool IsCommit = true)
356 {
357 if (T1 == null || T1.Count == 0) return false;
358
359 T1.ToList().ForEach(item =>
360 {
361 _Context.Set<T>().Attach(item);
362 _Context.Set<T>().Remove(item);
363 });
364
365 if (IsCommit)
366 return _Context.SaveChanges() > 0;
367 else
368 return false;
369 }
370 /// <summary>
371 /// 删除多条记录，同一模型（异步方式）
372 /// </summary>
373 /// <param name="T1">实体模型集合</param>
374 /// <param name="IsCommit">是否提交（默认提交）</param>
375 /// <returns></returns>
376 public virtual async Task<bool> DeleteListAsync(List<T> T1, bool IsCommit = true)
377 {
378 if (T1 == null || T1.Count == 0) return await Task.Run(() => false);
379
380 T1.ToList().ForEach(item =>
381 {
382 _Context.Set<T>().Attach(item);
383 _Context.Set<T>().Remove(item);
384 });
385
386 if (IsCommit)
387 return await Task.Run(() => _Context.SaveChanges() > 0);
388 else
389 return await Task.Run(() => false);
390 }
391
392 /// <summary>
393 /// 删除多条记录，独立模型
394 /// </summary>
395 /// <param name="T1">实体模型集合</param>
396 /// <param name="IsCommit">是否提交（默认提交）</param>
397 /// <returns></returns>
398 public virtual bool DeleteList<T1>(List<T1> T, bool IsCommit = true) where T1 : class
399 {
400 if (T == null || T.Count == 0) return false;
401
402 T.ToList().ForEach(item =>
403 {
404 _Context.Set<T1>().Attach(item);
405 _Context.Set<T1>().Remove(item);
406 });
407
408 if (IsCommit)
409 return _Context.SaveChanges() > 0;
410 else
411 return false;
412 }
413 /// <summary>
414 /// 删除多条记录，独立模型（异步方式）
415 /// </summary>
416 /// <param name="T1">实体模型集合</param>
417 /// <param name="IsCommit">是否提交（默认提交）</param>
418 /// <returns></returns>
419 public virtual async Task<bool> DeleteListAsync<T1>(List<T1> T, bool IsCommit = true) where T1 : class
420 {
421 if (T == null || T.Count == 0) return await Task.Run(() => false);
422
423 T.ToList().ForEach(item =>
424 {
425 _Context.Set<T1>().Attach(item);
426 _Context.Set<T1>().Remove(item);
427 });
428
429 if (IsCommit)
430 return await Task.Run(() => _Context.SaveChanges() > 0);
431 else
432 return await Task.Run(() => false);
433 }
434
435 /// <summary>
436 /// 通过Lamda表达式，删除一条或多条记录
437 /// </summary>
438 /// <param name="predicate"></param>
439 /// <param name="IsCommit"></param>
440 /// <returns></returns>
441 public virtual bool Delete(Expression<Func<T, bool>> predicate, bool IsCommit = true)
442 {
443 IQueryable<T> entry = (predicate == null) ? _Context.Set<T>().AsQueryable() : _Context.Set<T>().Where(predicate);
444 List<T> list = entry.ToList();
445
446 if (list != null && list.Count == 0) return false;
447 list.ForEach(item => {
448 _Context.Set<T>().Attach(item);
449 _Context.Set<T>().Remove(item);
450 });
451
452 if (IsCommit)
453 return _Context.SaveChanges() > 0;
454 else
455 return false;
456 }
457 /// <summary>
458 /// 通过Lamda表达式，删除一条或多条记录（异步方式）
459 /// </summary>
460 /// <param name="predicate"></param>
461 /// <param name="IsCommit"></param>
462 /// <returns></returns>
463 public virtual async Task<bool> DeleteAsync(Expression<Func<T, bool>> predicate, bool IsCommit = true)
464 {
465 IQueryable<T> entry = (predicate == null) ? _Context.Set<T>().AsQueryable() : _Context.Set<T>().Where(predicate);
466 List<T> list = entry.ToList();
467
468 if (list != null && list.Count == 0) return await Task.Run(() => false);
469 list.ForEach(item => {
470 _Context.Set<T>().Attach(item);
471 _Context.Set<T>().Remove(item);
472 });
473
474 if (IsCommit)
475 return await Task.Run(() => _Context.SaveChanges() > 0);
476 else
477 return await Task.Run(() => false);
478 }
479
480 #endregion
481
482 #region 获取多条数据操作
483
484 /// <summary>
485 /// Lamda返回IQueryable集合，延时加载数据
486 /// </summary>
487 /// <param name="predicate"></param>
488 /// <returns></returns>
489 public virtual IQueryable<T> LoadAll(Expression<Func<T, bool>> predicate)
490 {
491 return predicate != null ? _Context.Set<T>().Where(predicate).AsNoTracking<T>() : _Context.Set<T>().AsQueryable<T>().AsNoTracking<T>();
492 }
493 /// <summary>
494 /// 返回IQueryable集合，延时加载数据（异步方式）
495 /// </summary>
496 /// <param name="predicate"></param>
497 /// <returns></returns>
498 public virtual async Task<IQueryable<T>> LoadAllAsync(Expression<Func<T, bool>> predicate)
499 {
500 return predicate != null ? await Task.Run(()=> _Context.Set<T>().Where(predicate).AsNoTracking<T>()) : await Task.Run(() => _Context.Set<T>().AsQueryable<T>().AsNoTracking<T>());
501 }
502
503 /// <summary>
504 /// 返回List<T>集合,不采用延时加载
505 /// </summary>
506 /// <param name="predicate"></param>
507 /// <returns></returns>
508 public virtual List<T> LoadListAll(Expression<Func<T, bool>> predicate)
509 {
510 return predicate != null ? _Context.Set<T>().Where(predicate).AsNoTracking().ToList() : _Context.Set<T>().AsQueryable<T>().AsNoTracking().ToList();
511 }
512 // <summary>
513 /// 返回List<T>集合,不采用延时加载（异步方式）
514 /// </summary>
515 /// <param name="predicate"></param>
516 /// <returns></returns>
517 public virtual async Task<List<T>> LoadListAllAsync(Expression<Func<T, bool>> predicate)
518 {
519 return predicate != null ? await Task.Run(() => _Context.Set<T>().Where(predicate).AsNoTracking().ToList()) : await Task.Run(() => _Context.Set<T>().AsQueryable<T>().AsNoTracking().ToList());
520 }
521
522 /// <summary>
523 /// T-Sql方式：返回IQueryable<T>集合
524 /// </summary>
525 /// <param name="sql">SQL语句</param>
526 /// <param name="para">Parameters参数</param>
527 /// <returns></returns>
528 public virtual IQueryable<T> LoadAllBySql(string sql, params DbParameter[] para)
529 {
530 return _Context.Set<T>().FromSql(sql, para);
531 }
532 /// <summary>
533 /// T-Sql方式：返回IQueryable<T>集合（异步方式）
534 /// </summary>
535 /// <param name="sql">SQL语句</param>
536 /// <param name="para">Parameters参数</param>
537 /// <returns></returns>
538 public virtual async Task<IQueryable<T>> LoadAllBySqlAsync(string sql, params DbParameter[] para)
539 {
540 return await Task.Run(() => _Context.Set<T>().FromSql(sql, para));
541 }
542
543
544 /// <summary>
545 /// T-Sql方式：返回List<T>集合
546 /// </summary>
547 /// <param name="sql">SQL语句</param>
548 /// <param name="para">Parameters参数</param>
549 /// <returns></returns>
550 public virtual List<T> LoadListAllBySql(string sql, params DbParameter[] para)
551 {
552 return _Context.Set<T>().FromSql(sql, para).Cast<T>().ToList();
553 }
554 /// <summary>
555 /// T-Sql方式：返回List<T>集合（异步方式）
556 /// </summary>
557 /// <param name="sql">SQL语句</param>
558 /// <param name="para">Parameters参数</param>
559 /// <returns></returns>
560 public virtual async Task<List<T>> LoadListAllBySqlAsync(string sql, params DbParameter[] para)
561 {
562 return await Task.Run(()=> _Context.Set<T>().FromSql(sql, para).Cast<T>().ToList());
563 }
564
565 /// <summary>
566 /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合
567 /// </summary>
568 /// <typeparam name="TEntity">实体对象</typeparam>
569 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
570 /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
571 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
572 /// <param name="orderby">排序字段</param>
573 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
574 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
575 /// <returns>实体集合</returns>
576 public virtual List<TResult> QueryEntity<TEntity, TOrderBy, TResult>
577 (Expression<Func<TEntity, bool>> where,
578 Expression<Func<TEntity, TOrderBy>> orderby,
579 Expression<Func<TEntity, TResult>> selector,
580 bool IsAsc)
581 where TEntity : class
582 where TResult : class
583 {
584 IQueryable<TEntity> query = _Context.Set<TEntity>();
585 if (where != null)
586 {
587 query = query.Where(where);
588 }
589
590 if (orderby != null)
591 {
592 query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
593 }
594 if (selector == null)
595 {
596 return query.Cast<TResult>().AsNoTracking().ToList();
597 }
598 return query.Select(selector).AsNoTracking().ToList();
599 }
600 /// <summary>
601 /// 可指定返回结果、排序、查询条件的通用查询方法，返回实体对象集合（异步方式）
602 /// </summary>
603 /// <typeparam name="TEntity">实体对象</typeparam>
604 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
605 /// <typeparam name="TResult">数据结果，与TEntity一致</typeparam>
606 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
607 /// <param name="orderby">排序字段</param>
608 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
609 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
610 /// <returns>实体集合</returns>
611 public virtual async Task<List<TResult>> QueryEntityAsync<TEntity, TOrderBy, TResult>
612 (Expression<Func<TEntity, bool>> where,
613 Expression<Func<TEntity, TOrderBy>> orderby,
614 Expression<Func<TEntity, TResult>> selector,
615 bool IsAsc)
616 where TEntity : class
617 where TResult : class
618 {
619 IQueryable<TEntity> query = _Context.Set<TEntity>();
620 if (where != null)
621 {
622 query = query.Where(where);
623 }
624
625 if (orderby != null)
626 {
627 query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
628 }
629 if (selector == null)
630 {
631 return await Task.Run(() => query.Cast<TResult>().AsNoTracking().ToList());
632 }
633 return await Task.Run(() => query.Select(selector).AsNoTracking().ToList());
634 }
635
636 /// <summary>
637 /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合
638 /// </summary>
639 /// <typeparam name="TEntity">实体对象</typeparam>
640 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
641 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
642 /// <param name="orderby">排序字段</param>
643 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
644 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
645 /// <returns>自定义实体集合</returns>
646 public virtual List<object> QueryObject<TEntity, TOrderBy>
647 (Expression<Func<TEntity, bool>> where,
648 Expression<Func<TEntity, TOrderBy>> orderby,
649 Func<IQueryable<TEntity>,
650 List<object>> selector,
651 bool IsAsc)
652 where TEntity : class
653 {
654 IQueryable<TEntity> query = _Context.Set<TEntity>();
655 if (where != null)
656 {
657 query = query.Where(where);
658 }
659
660 if (orderby != null)
661 {
662 query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
663 }
664 if (selector == null)
665 {
666 return query.AsNoTracking().ToList<object>();
667 }
668 return selector(query);
669 }
670 /// <summary>
671 /// 可指定返回结果、排序、查询条件的通用查询方法，返回Object对象集合（异步方式）
672 /// </summary>
673 /// <typeparam name="TEntity">实体对象</typeparam>
674 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
675 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
676 /// <param name="orderby">排序字段</param>
677 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
678 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
679 /// <returns>自定义实体集合</returns>
680 public virtual async Task<List<object>> QueryObjectAsync<TEntity, TOrderBy>
681 (Expression<Func<TEntity, bool>> where,
682 Expression<Func<TEntity, TOrderBy>> orderby,
683 Func<IQueryable<TEntity>,
684 List<object>> selector,
685 bool IsAsc)
686 where TEntity : class
687 {
688 IQueryable<TEntity> query = _Context.Set<TEntity>();
689 if (where != null)
690 {
691 query = query.Where(where);
692 }
693
694 if (orderby != null)
695 {
696 query = IsAsc ? query.OrderBy(orderby) : query.OrderByDescending(orderby);
697 }
698 if (selector == null)
699 {
700 return await Task.Run(() => query.AsNoTracking().ToList<object>());
701 }
702 return await Task.Run(() => selector(query));
703 }
704
705
706 /// <summary>
707 /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合
708 /// </summary>
709 /// <typeparam name="TEntity">实体对象</typeparam>
710 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
711 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
712 /// <param name="orderby">排序字段</param>
713 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
714 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
715 /// <returns>动态类</returns>
716 public virtual dynamic QueryDynamic<TEntity, TOrderBy>
717 (Expression<Func<TEntity, bool>> where,
718 Expression<Func<TEntity, TOrderBy>> orderby,
719 Func<IQueryable<TEntity>,
720 List<object>> selector,
721 bool IsAsc)
722 where TEntity : class
723 {
724 List<object> list = QueryObject<TEntity, TOrderBy>
725 (where, orderby, selector, IsAsc);
726 return Common.JsonHelper.JsonConvert.JsonClass(list);
727 }
728 /// <summary>
729 /// 可指定返回结果、排序、查询条件的通用查询方法，返回动态类对象集合（异步方式）
730 /// </summary>
731 /// <typeparam name="TEntity">实体对象</typeparam>
732 /// <typeparam name="TOrderBy">排序字段类型</typeparam>
733 /// <param name="where">过滤条件，需要用到类型转换的需要提前处理与数据表一致的</param>
734 /// <param name="orderby">排序字段</param>
735 /// <param name="selector">返回结果（必须是模型中存在的字段）</param>
736 /// <param name="IsAsc">排序方向，true为正序false为倒序</param>
737 /// <returns>动态类</returns>
738 public virtual async Task<dynamic> QueryDynamicAsync<TEntity, TOrderBy>
739 (Expression<Func<TEntity, bool>> where,
740 Expression<Func<TEntity, TOrderBy>> orderby,
741 Func<IQueryable<TEntity>,
742 List<object>> selector,
743 bool IsAsc)
744 where TEntity : class
745 {
746 List<object> list = QueryObject<TEntity, TOrderBy>
747 (where, orderby, selector, IsAsc);
748 return await Task.Run(() => Common.JsonHelper.JsonConvert.JsonClass(list)) ;
749 }
750
751 #endregion
752
753 #region 验证是否存在
754
755 /// <summary>
756 /// 验证当前条件是否存在相同项
757 /// </summary>
758 public virtual bool IsExist(Expression<Func<T, bool>> predicate)
759 {
760 var entry = _Context.Set<T>().Where(predicate);
761 return (entry.Any());
762 }
763 /// <summary>
764 /// 验证当前条件是否存在相同项（异步方式）
765 /// </summary>
766 public virtual async Task<bool> IsExistAsync(Expression<Func<T, bool>> predicate)
767 {
768 var entry = _Context.Set<T>().Where(predicate);
769 return await Task.Run(() => entry.Any());
770 }
771
772 /// <summary>
773 /// 根据SQL验证实体对象是否存在
774 /// </summary>
775 public virtual bool IsExist(string sql, params DbParameter[] para)
776 {
777 return _Context.Database.ExecuteSqlCommand(sql, para) > 0;
778 }
779 /// <summary>
780 /// 根据SQL验证实体对象是否存在（异步方式）
781 /// </summary>
782 public virtual async Task<bool> IsExistAsync(string sql, params DbParameter[] para)
783 {
784 return await Task.Run(() => _Context.Database.ExecuteSqlCommand(sql, para) > 0);
785 }
786
787 #endregion
788
789 }
希望跟大家一起学习Asp.net Core
刚开始接触，水平有限，很多东西都是自己的理解和翻阅网上大神的资料，如果有不对的地方和不理解的地方，希望大家指正！
虽然Asp.net Core 现在很火热，但是网上的很多资料都是前篇一律的复制，所以有很多问题我也暂时没有解决，希望大家能共同帮助一下！
【无私分享：ASP.NET CORE 项目实战（第五章）】Repository仓储 UnitofWork
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原文地址：http://www.cnblogs.com/zhangxiaolei521/p/5808403.html
