基于.NET平台的分层架构实战（九）——数据访问层的第三种实现：基于NBear框架的ORM实现

4.实现数据访问层
做完上述工作，我们就可以来实现数据访问层了。借助于NBear框架的支持，我们可以非常方便的使用ORM方式访问数据库。关于NBear的细节，这里不再赘述，以管理员为例，具体代码如下：

AdminDAL.cs
1using System;
2using System.Collections.Generic;
3using System.Text;
4using System.Data.Common;
5using NGuestBook.IDAL;
6using NGuestBook.Entity;
7using NBear.Common;
8using NBear.Data;
9
10namespace NGuestBook.NBearDAL
11{
12 public class AdminDAL : IAdminDAL
13 {
14 /**//// <summary>
15 /// 插入管理员
16 /// </summary>
17 /// <param name=”admin”>管理员实体类</param>
18 /// <returns>是否成功</returns>
19 public bool Insert(AdminInfo admin)
20 {
21 Gateway.SetDefaultDatabase(“NBearConnectionString”);
22 DbTransaction transcation = Gateway.Default.BeginTransaction();
23 try
24 {
25 Gateway.Default.Save<TAdmin>(AdminConvertor.CommonEntityToNBearEntity(admin));
26 transcation.Commit();
27 return true;
28 }
29 catch
30 {
31 transcation.Rollback();
32 return false;
33 }
34 finally
35 {
36 Gateway.Default.CloseTransaction(transcation);
37 }
38 }
39
40 /**//// <summary>
41 /// 删除管理员
42 /// </summary>
43 /// <param name=”id”>欲删除的管理员的ID</param>
44 /// <returns>是否成功</returns>
45 public bool Delete(int id)
46 {
47 Gateway.SetDefaultDatabase(“NBearConnectionString”);
48 DbTransaction transcation = Gateway.Default.BeginTransaction();
49 try
50 {
51 Gateway.Default.Delete<TAdmin>(id);
52 transcation.Commit();
53 return true;
54 }
55 catch
56 {
57 transcation.Rollback();
58 return false;
59 }
60 finally
61 {
62 Gateway.Default.CloseTransaction(transcation);
63 }
64 }
65
66 /**//// <summary>
67 /// 更新管理员信息
68 /// </summary>
69 /// <param name=”admin”>管理员实体类</param>
70 /// <returns>是否成功</returns>
71 public bool Update(AdminInfo admin)
72 {
73 Gateway.SetDefaultDatabase(“NBearConnectionString”);
74 DbTransaction transcation = Gateway.Default.BeginTransaction();
75 PropertyItem[] properties = {
76 new PropertyItem(“Name”),
77 new PropertyItem(“Password”)
78 };
79 object[] values ={
80 admin.Name,
81 admin.Password
82 };
83 try
84 {
85 Gateway.Default.Update<TAdmin>(properties, values, null, transcation);
86 transcation.Commit();
87 return true;
88 }
89 catch
90 {
91 transcation.Rollback();
92 return false;
93 }
94 finally
95 {
96 Gateway.Default.CloseTransaction(transcation);
97 }
98 }
99
100 /**//// <summary>
101 /// 按ID取得管理员信息
102 /// </summary>
103 /// <param name=”id”>管理员ID</param>
104 /// <returns>管理员实体类</returns>
105 public AdminInfo GetByID(int id)
106 {
107 Gateway.SetDefaultDatabase(“NBearConnectionString”);
108 TAdmin tAdmin = Gateway.Default.Find<TAdmin>(TAdmin._.ID == id);
109 return tAdmin == null ? null : AdminConvertor.NBearEntityToCommonEntity(tAdmin);
110 }
111
112 /**//// <summary>
113 /// 按用户名及密码取得管理员信息
114 /// </summary>
115 /// <param name=”name”>用户名</param>
116 /// <param name=”password”>密码</param>
117 /// <returns>管理员实体类，不存在时返回null</returns>
118 public AdminInfo GetByNameAndPassword(string name, string password)
119 {
120 Gateway.SetDefaultDatabase(“NBearConnectionString”);
121 TAdmin tAdmin = Gateway.Default.Find<TAdmin>(TAdmin._.Name == name && TAdmin._.Password == password);
122 return tAdmin == null ? null : AdminConvertor.NBearEntityToCommonEntity(tAdmin);
123 }
124
125 /**//// <summary>
126 /// 按管理员名取得管理员信息
127 /// </summary>
128 /// <param name=”name”>管理员名</param>
129 /// <returns>管理员实体类</returns>
130 public AdminInfo GetByName(string name)
131 {
132 Gateway.SetDefaultDatabase(“NBearConnectionString”);
133 TAdmin tAdmin = Gateway.Default.Find<TAdmin>(TAdmin._.Name == name);
134 return tAdmin == null ? null : AdminConvertor.NBearEntityToCommonEntity(tAdmin);
135 }
136
137 /**//// <summary>
138 /// 取得全部管理员信息
139 /// </summary>
140 /// <returns>管理员实体类集合</returns>
141 public IList<AdminInfo> GetAll()
142 {
143 IList<AdminInfo> adminCollection = new List<AdminInfo>();
144 Gateway.SetDefaultDatabase(“NBearConnectionString”);
145 TAdmin[] tAdminCollection = Gateway.Default.FindArray<TAdmin>(null, TAdmin._.ID.Desc);
146 foreach (TAdmin tAdmin in tAdminCollection)
147 {
148 adminCollection.Add(AdminConvertor.NBearEntityToCommonEntity(tAdmin));
149 }
150 return adminCollection;
151 }
152 }
153}

来源：http://www.cnblogs.com/leoo2sk