初学SqlHelper - 实现增删改查

 1 //数据库连接字符串
 2       public static readonly string constr = ConfigurationManager.ConnectionStrings["connstr"].ConnectionString;
 3 
 4       //打开数据库
 5       public static SqlConnection OpenConnection()
 6       {
 7         SqlConnection conn = new SqlConnection(constr);
 8         conn.Open();
 9         return conn;
10       }
11 
12       //执行不返回结果的sql，用于插入和更新，删除
13       public static int ExecuteNonQuery(string cmdText, params SqlParameter[] parameters)
14       {
15         using (SqlConnection conn = new SqlConnection(constr))
16         {
17           conn.Open();
18           return ExecuteNonQuery(conn, cmdText, parameters);
19         }
20       }
21 
22       //上面方法的重载方法
23       public static int ExecuteNonQuery(SqlConnection conn, string cmdText, params SqlParameter[] parameters)
24       {
25         using (SqlCommand cmd = conn.CreateCommand())
26         {
27           cmd.CommandText = cmdText;
28           cmd.Parameters.AddRange(parameters);
29           return cmd.ExecuteNonQuery();
30         }
31       }
32 
33       //返回对象类型的sql查询，对象单个数据记录的中的某个值，或者count(*)计算的结果，在分页中会经常用到。
34       public static object ExecuteScalar(string cmdText, params SqlParameter[] parameters)
35       {
36         using (SqlConnection conn = new SqlConnection(constr))
37         {
38           conn.Open();
39           return ExecuteScalar(conn, cmdText, parameters);
40         }
41       }
42 
43       //以上方法的重载方法
44       public static object ExecuteScalar(SqlConnection conn, string cmdText, params SqlParameter[] parameters)
45       {
46         using (SqlCommand cmd = conn.CreateCommand())
47         {
48           cmd.CommandText = cmdText;
49           cmd.Parameters.AddRange(parameters);
50           return cmd.ExecuteScalar();
51         }
52       }
53 
54       //获得数据表格的查询
55       public static DataTable ExecuteDataTable(string cmdText, params SqlParameter[] parameters)
56       {
57         using (SqlConnection conn = new SqlConnection(constr))
58         {
59           conn.Open();
60           return ExecuteDataTable(conn, cmdText, parameters);
61         }
62       }
63 
64       //以上方法的重载
65       public static DataTable ExecuteDataTable(SqlConnection conn, string cmdText, params SqlParameter[] parameters)
66       {
67         using (SqlCommand cmd = conn.CreateCommand())
68         {
69           cmd.CommandText = cmdText;
70           cmd.Parameters.AddRange(parameters);
71           using (SqlDataAdapter adapter = new SqlDataAdapter(cmd))
72           {
73             DataTable dt = new DataTable();
74             adapter.Fill(dt);
75             return dt;
76           }
77         }
78       }

View Code - SqlHelper