5 SQlHelper

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.SqlClient;
using System.Configuration;
using System.Data;

namespace SQlHelper登录
{
    class SQlHelper
    {
        public static int ExecuteNonQuery(string sql ,params SqlParameter [] parameters)
        {  
            string constr = ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
            using (SqlConnection conn =new SqlConnection (constr))
            {
                conn.Open();
                using (SqlCommand cmd=conn.CreateCommand ())
                {
                    cmd.CommandText = sql;
                    foreach ( SqlParameter parameter in parameters  )
                    {
                        cmd.Parameters.Add(parameter);
                    }
                    return cmd.ExecuteNonQuery();
                }
            }

        }
        public static object  ExecuteScalar(string sql, params SqlParameter[] parameters)
        {
            string constr = ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
            using (SqlConnection conn = new SqlConnection(constr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = sql;
                    foreach (SqlParameter parameter in parameters)
                    {
                        cmd.Parameters.Add(parameter);
                    }
                    return cmd.ExecuteScalar();
                 
                }
            }

        }
        public static DataTable ExecuteTables(string sql, params SqlParameter[] parameters)
        {
            string constr = ConfigurationManager.ConnectionStrings["ConStr"].ConnectionString;
            using (SqlConnection conn = new SqlConnection(constr))
            {
                conn.Open();
                using (SqlCommand cmd = conn.CreateCommand())
                {
                    cmd.CommandText = sql;
                    foreach (SqlParameter parameter in parameters)
                    {
                        cmd.Parameters.Add(parameter);
                    }
                    DataSet dataset = new DataSet();
                    SqlDataAdapter adapter = new SqlDataAdapter(cmd);
                    adapter.Fill(dataset);
                    DataTable datatable=dataset.Tables[0];
                    return datatable;
                }
            }

        }

    }
}