데이터베이스 작업 중의 SqlHelper 방법

 1 class SqlHelper
 2     {
 3         private static string connStr = ConfigurationManager.ConnectionStrings["connStr"].ConnectionString;
 4 
 5         public static int ExecuteNonQuery(string cmdStr,params SqlParameter[] parameters)
 6         {
 7             using (SqlConnection conn = new SqlConnection(connStr))
 8             {
 9                 conn.Open();
10                 using (SqlCommand cmd = conn.CreateCommand())
11                 {
12                     cmd.CommandText = cmdStr;
13                     cmd.Parameters.AddRange(parameters);
14                     return cmd.ExecuteNonQuery();
15                 }
16             }
17         }
18 
19         public static object ExecuteScalar(string cmdStr, params SqlParameter[] parameters)
20         {
21             using (SqlConnection conn = new SqlConnection(connStr))
22             {
23                 conn.Open();
24                 using (SqlCommand cmd = conn.CreateCommand())
25                 {
26                     cmd.CommandText = cmdStr;
27                     cmd.Parameters.AddRange(parameters);
28                     return cmd.ExecuteScalar();
29                 }
30             }
31         }
32 
33         public static DataTable ExecuteDataTable(string cmdStr, params SqlParameter[] parameters)
34         {
35             using (SqlConnection conn = new SqlConnection(connStr))
36             {
37                 conn.Open();
38                 using (SqlCommand cmd = conn.CreateCommand())
39                 {
40                     DataTable dt = new DataTable();
41                     cmd.CommandText = cmdStr;
42                     cmd.Parameters.AddRange(parameters);
43                     SqlDataAdapter adapter = new SqlDataAdapter(cmd);
44                     adapter.Fill(dt);
45                     return dt;
46                 }
47             }
48 
49         }
50     }