三层框架Dal层 sqlHelper内容

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;
namespace Dal
{
    class sqlhelper
    {
        static string constr = ConfigurationManager.ConnectionStrings["constr"].ConnectionString;
        static SqlConnection conn = new SqlConnection(constr);

        public static void ConnOpen()
        {
            if (conn.State == System.Data.ConnectionState.Closed)
            {
                conn.Open();
            }
        }
        public static void ConnClose()
        {
            if (conn.State == System.Data.ConnectionState.Open)
            {
                conn.Close();
            }
        }
        //封装查询
        public static SqlDataReader ExecuteReader(string sql, params object[] parms)
        {
            ConnOpen();
            SqlCommand cmd = new SqlCommand(sql, conn);
            for (int i = 0; i < parms.Length; i++)
            {
                cmd.Parameters.AddWithValue("@" + i, parms[i]);
            }
            SqlDataReader sdr = cmd.ExecuteReader();
            return sdr;
        }
        // 封装修改(删除 增加 更新)
        public static bool GetExcuteNonQuery(string sql, params object[] parms)
        {
            ConnOpen();
            SqlCommand cmd = new SqlCommand(sql, conn);
            for (int i = 0; i < parms.Length; i++)
            {
                cmd.Parameters.AddWithValue("@" + i, parms[i]);
            }
            int j = cmd.ExecuteNonQuery();
            if (j > 0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        //封装执行返回第一行第一列的语句
        public static object GetExcuteScalar(string sql, params object[] parms)
        {
            ConnOpen();
            SqlCommand cmd = new SqlCommand(sql, conn);
            for (int i = 0; i < parms.Length; i++)
            {
                cmd.Parameters.AddWithValue("@" + i, parms[i]);
            }
            object obj = cmd.ExecuteScalar();
            return obj;
        }

        //封装数据集
        public static DataTable GetDateTable(string sql, params object[] parms)
        {

            SqlDataAdapter sda = new SqlDataAdapter(sql, constr);
            for (int i = 0; i < parms.Length; i++)
            {
                sda.SelectCommand.Parameters.AddWithValue("@" + i, parms[i]);
            }
            DataTable dt = new DataTable();
            sda.Fill(dt);
            return dt;
        }

        //可以分页 ，也可以以获取数据起始
        public static DataSet GetDateSet(string sql, int index, int maxcount, string name, params object[] parms)
        {
            SqlDataAdapter sda = new SqlDataAdapter(sql, constr);
            for (int i = 0; i < parms.Length; i++)
            {
                sda.SelectCommand.Parameters.AddWithValue("@" + i, parms[i]);
            }
            DataTable dt = new DataTable();
            DataSet ds = new DataSet();
            sda.Fill(ds, index, maxcount, name);
            return ds;
        }

        /// <summary>
        /// 
        /// </summary>
        /// <param name="sql">要执行的sql语句</param>
        /// <param name="commandType">要执行的查询语句类型，如存储过程或SQL文本命令</param>
        /// <param name="parameters">Transact-SQL语句或者存储过程的参数数组</param>
        /// <returns></returns>
        public static int getExecuteNonQuery(string sql, CommandType commandType, SqlParameter[] parameters)
        {
            SqlConnection conn = new SqlConnection(constr);
            SqlCommand cmd = new SqlCommand(sql, conn) { CommandType = commandType };
            if (parameters != null)
            {
                foreach (SqlParameter parameter in parameters)
                {
                    cmd.Parameters.Add(parameter);
                }
            }
            conn.Open();
            int count = cmd.ExecuteNonQuery();
            conn.Close();
            return count;
        }


    }
}