【SQLServer】DBHelper即Ｃ＃数据库底层封装

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Configuration;
using System.Data.SqlClient;
using System.Data;
namespace MYHelper
{
    //不加public，只有dal私有引用；
    //封装执行sql server增删改查辅助类，提供相应执行sql语句和存储过程的方法
    //作者：白宁超（http://www.cnblogs.com/baiboy/）
	static class SQLHelper
    {
        //读取配置文件中的连接字符串
        static string connstr = ConfigurationManager.ConnectionStrings["sql"].ConnectionString;
        /// <summary>
        /// 执行非查询sql语句，返回受影响行数，如果执行非增删改则返回-1
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="paras">参数数组</param>
        /// <returns>影响行数res</returns>
        public static int ExecuteNonQuery(string sql, params SqlParameter[] paras)
        {
            int res = -1;
            using (SqlConnection conn = new SqlConnection(connstr))
            {
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    cmd.CommandType = CommandType.StoredProcedure;
                    if (paras != null || paras.Length > 0)
                    {
                        cmd.Parameters.AddRange(paras);
                    }
                    conn.Open();
                    res = cmd.ExecuteNonQuery();
                }
            }
            return res;
        }
        /// <summary>
        /// 执行非查询sql语句，返回受影响行数，如果执行非增删改则返回-1
        /// </summary>
        /// <param name="sql">sql语句</param>
        /// <param name="paras">参数数组</param>
        /// <returns>影响行数res</returns>
         public static int ExecuteNonParaQuery(string sql)
         {
             int res = -1;
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     conn.Open();
                     res = cmd.ExecuteNonQuery();
                 }
             }
             return res;
         }
         /// <summary>
         /// 执行读取数据，返回一个对象
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras">参数数组</param>
         /// <returns>返回一个对象o</returns>
         public static object ExecuteScalar(string sql, params SqlParameter[] paras)
         {
             object  o = null;
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     cmd.CommandType = CommandType.StoredProcedure;
                     if (paras != null)
                     {
                         cmd.Parameters.AddRange(paras);
                     }
                     conn.Open();
                     o = cmd.ExecuteScalar();
                 }
             }
             return o;
         }
         /// <summary>
         /// 执行查询sql语句，返回一个对象
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras">查询参数</param>
         /// <returns>返回DataReader对象</returns>
         public static SqlDataReader ExecuteReader(string sql, params SqlParameter[] paras)
         {
             SqlConnection conn = new SqlConnection(connstr);
             using (SqlCommand cmd = new SqlCommand(sql, conn))
             {
                 cmd.CommandType = CommandType.StoredProcedure;
                 if (paras != null)
                 {
                     cmd.Parameters.AddRange(paras);
                 }
                 conn.Open();
                 try
                 {
                     return cmd.ExecuteReader(CommandBehavior.CloseConnection);
                 }
                 catch (Exception ex)
                 {
                     cmd.Dispose();
                     throw ex;
                 }
             }
         }

         /// <summary>
         /// 执行查询sql语句，返回一个无参数dataset对象
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras"></param>
         /// <returns>返回dataset 对象</returns>
         public static DataSet GetDataSetNotPara(string sql)
         {
             DataSet ds = new DataSet();
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     //根据传来的参数。决定是sql语句还是存储过程
                     cmd.CommandType = CommandType.StoredProcedure;
                     conn.Open();
                     using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                     {
                         sda.Fill(ds);
                     }
                 }
             }
             return ds;
         }
		 
         /// <summary>
         /// 执行查询sql语句，返回一个无参数dataset对象
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras"></param>
         /// <returns>返回dataset 对象</returns>
         public static DataTable  GetDataTableNotPara(string sql)
         {
             DataTable dt = new DataTable();
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     //根据传来的参数。决定是sql语句还是存储过程
                  
                     conn.Open();
                     using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                     {
                         sda.Fill(dt);
                     }
                 }
             }
             return dt;
         }

         /// <summary>
         /// 执行查询sql语句，返回一个dataset对象
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras">查询参数</param>
         /// <returns>返回dataset 对象</returns>
         public static DataSet GetDataSet(string sql, params SqlParameter[] paras)
         {
             DataSet  ds = new DataSet();
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     //根据传来的参数。决定是sql语句还是存储过程
                     cmd.CommandType = CommandType.StoredProcedure;
                     //添加参数
                     cmd.Parameters.AddRange(paras);
                     conn.Open();
                     using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                     {
                         sda.Fill(ds);
                     }
                 }
             }
             return ds;
         }
         /// <summary>
         /// 可以执行sql语句或存储过程
         /// </summary>
         /// <param name="text"></param>
         /// <param name="ct"></param>
         /// <param name="param"></param>
         /// <returns></returns>
         public static DataTable ProcGetTable(string sql, params SqlParameter[] param)
         {
             DataTable dt = new DataTable();

             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlCommand cmd = new SqlCommand(sql, conn))
                 {
                     //根据传来的参数。决定是sql语句还是存储过程
                     
                     cmd.CommandType = CommandType.StoredProcedure;
                     //添加参数
                     cmd.Parameters.AddRange(param);
                     //cmd.Parameters.Add("@name", SqlDbType.NVarChar, 20).Value = param[0];
                     //cmd.Parameters.Add("@pwd", SqlDbType.NVarChar, 20).Value = param[1];
                     conn.Open();
                     using (SqlDataAdapter sda = new SqlDataAdapter(cmd))
                     {
                         sda.Fill(dt);
                     }
                 }
             }
             return dt;
         }
        
         /// <summary>
         /// 实现分页功能
         /// </summary>
         /// <param name="sql">sql语句</param>
         /// <param name="paras">参数数组（显示index页和每页显示条数size）</param>
         /// <returns>查询结果</returns>
         public static DataTable GetParaTable(string sql, params SqlParameter[] paras)
         {
             DataSet ds = new DataSet();
             using (SqlConnection conn = new SqlConnection(connstr))
             {
                 using (SqlDataAdapter da = new SqlDataAdapter(sql, conn))
                 {
                     if (paras != null)
                     {
                         da.SelectCommand.Parameters.AddRange(paras);
                     }
                     da.SelectCommand.CommandType = CommandType.StoredProcedure;
                     da.Fill(ds);
                 }
             }
             return ds.Tables[0];
         }
    }
}