WPF中SqlHelper

using System; using System.Collections.Generic; using System.Linq; using System.Text; using System.Configuration; using System.Data; using System.Data.SqlClient; namespace 数据绑定 {     class SqlHelper     {         private static string strconn= ConfigurationManager.ConnectionStrings["dbstrConn"].ConnectionString;         public static int ExecuteNonQuery(string sql)         {             using (SqlConnection conn = new SqlConnection(strconn))             {                 conn.Open();                 using (SqlCommand cmd = conn.CreateCommand())                 {                     cmd.CommandText = sql;                     return cmd.ExecuteNonQuery();                 }                              }         }         public static object ExecuteScalar(string sql)         {             using (SqlConnection conn = new SqlConnection(strconn))             {                 conn.Open();                 using (SqlCommand cmd = conn.CreateCommand())                 {                     cmd.CommandText = sql;                     return cmd.ExecuteScalar();                 }              }         }         //查询少量数据         public static DataTable ExecuteTable(string sql)         {             using (SqlConnection conn = new SqlConnection(strconn))             {                 conn.Open();                 using (SqlCommand cmd = conn.CreateCommand())                 {                     cmd.CommandText = sql;                     SqlDataAdapter adapter = new SqlDataAdapter(cmd);                     DataSet dataset = new DataSet();                     adapter.Fill(dataset);                     return dataset.Tables[0];                    }              }         }     } }