C# SqlDBHelper帮助类

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

namespace ClassLibrary
{
    /// <summary>
    /// SqlDBHelper帮助类
    /// </summary>
    public class SqlDBHelper
    {
        public static SqlConnection connection;
        public static SqlConnection Connection
        {
            get
            {
                string connectionString = ConfigurationManager.ConnectionStrings["mybookshop"].ConnectionString;
                if (connection == null)
                {
                    connection = new SqlConnection(connectionString);
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Closed)
                {
                    connection = new SqlConnection(connectionString);
                    connection.Open();
                }
                else if (connection.State == System.Data.ConnectionState.Broken)
                {
                    connection.Close();
                    connection.Open();
                }
                return connection;
            }
        }
      
        /// <summary>
        /// 单个数据增，删，改
        /// </summary>
        /// <param name="safeSql"></param>
        /// <returns></returns>
        public static int ExecuteCommand(string safeSql)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    int result = cmd.ExecuteNonQuery();
                    return result;
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带多个参数的增，删，改
        /// </summary>
        /// <param name="safeSql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static int ExecuteCommand(string safeSql, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    cmd.Parameters.AddRange(values);
                    return cmd.ExecuteNonQuery();
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带多个参数的增，删，改
        /// </summary>
        /// <param name="safeSql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static int ExecuteCommand(string safeSql, CommandType type, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    cmd.CommandType = type;
                    cmd.Parameters.AddRange(values);
                    cmd.ExecuteNonQuery();
                    return cmd.ExecuteNonQuery();
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带多个参数的增，删，改
        /// </summary>
        /// <param name="safeSql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static int ExecuteCommand(string safeSql, CommandType type, int index)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    cmd.CommandType = type;
                    SqlParameter paramOne = new SqlParameter("@rid", SqlDbType.Int);
                    paramOne.Value = index;
                    cmd.Parameters.Add(paramOne);
                    return cmd.ExecuteNonQuery();
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 查单个值
        /// </summary>
        /// <param name="safeSql"></param>
        /// <returns></returns>
        public static int GetScalar(string safeSql)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    int result = Convert.ToInt32(cmd.ExecuteScalar());
                    return result;
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带参数的查询语句
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static int GetScalar(string sql, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(sql, Connection))
                {
                    cmd.Parameters.AddRange(values);
                    int result = Convert.ToInt32(cmd.ExecuteScalar());
                    return result;
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带执行类型的ExecuteScalar
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="type"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static int GetScalar(string sql, CommandType type, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(sql, Connection))
                {
                    cmd.CommandType = type;
                    cmd.Parameters.AddRange(values);
                    int result = Convert.ToInt32(cmd.ExecuteScalar());
                    return result;
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 查询表,获取多个记录
        /// </summary>
        /// <param name="safeSql"></param>
        /// <returns></returns>
        public static SqlDataReader GetReader(string safeSql)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    SqlDataReader reader = cmd.ExecuteReader();
                    return reader;
                }

            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
     
        /// <summary>
        /// 带参数的-查询表,获取多个记录
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static SqlDataReader GetReader(string sql, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(sql, Connection))
                {
                    cmd.Parameters.AddRange(values);
                    SqlDataReader reader = cmd.ExecuteReader();
                    return reader;
                }
            }
            catch (SqlException)
            {
                throw;
            }
        }
     
        /// <summary>
        /// 查询表,获取多个记录---语句，类型，参数
        /// </summary>
        /// <param name="safeSql"></param>
        /// <param name="cmdType"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static SqlDataReader GetReader(string safeSql, CommandType cmdType, params SqlParameter[] values)
        {
            try
            {
                using (SqlCommand cmd = new SqlCommand(safeSql, Connection))
                {
                    cmd.CommandType = cmdType;
                    cmd.Parameters.AddRange(values);
                    SqlDataReader reader = cmd.ExecuteReader();
                    return reader;
                }
            }
            catch (SqlException ex)
            {
                throw ex;
            }
        }
      
        /// <summary>
        /// 返回datatable
        /// </summary>
        /// <param name="safeSql"></param>
        /// <returns></returns>
        public static DataTable GetDataSet(string safeSql)
        {
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand(safeSql, Connection);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }
      
        /// <summary>
        ///  返回dataTable ,带参数使用
        /// </summary>
        /// <param name="sql"></param>
        /// <param name="values"></param>
        /// <returns></returns>
        public static DataTable GetDataSet(string sql, params SqlParameter[] values)
        {
            DataSet ds = new DataSet();
            SqlCommand cmd = new SqlCommand(sql, Connection);
            cmd.Parameters.AddRange(values);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            da.Fill(ds);
            return ds.Tables[0];
        }      
    }
}