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  • 程序部署到服务器后非常慢!!!

    结论:

    1、导致慢的主要原因是:索引 !此处where条件时间没有加索引。如果唯一则添加唯一索引,若不唯一则添加组合唯一索引。

    1、EF 查询 比ADO稍微慢一点点,原因不详。

    2、在原生ADO.Net中 使用 参数化查询 比 使用非参数化sql拼接  慢几十倍!!原因不详。

    ADO.Net代码测试

            public List<v_yjdateggjgModel> SelectList(int yjxzqid, int ncpid, DateTime start, DateTime end)
            {
                List<v_yjdateggjgModel> list = new List<v_yjdateggjgModel>();
           //第一条sql,采用参数化查询 用时36秒 查询1100条数据 // string sql = "select yjxzqid,ncpid,rq,sjttjg,sjpfjg,sjlsjg,ycttjg,ycpfjg,yclsjg from v_yjdateggjg where yjxzqid=@yjxzqid and ncpid=@ncpid and (rq>=@start and rq<=@end)";
           //第二条 sql,采用 sql拼接 用时1.5秒 查询 1100数据 string sql = "select yjxzqid,ncpid,rq,sjttjg,sjpfjg,sjlsjg,ycttjg,ycpfjg,yclsjg from v_yjdateggjg where yjxzqid = "+ yjxzqid + " and ncpid = "+ ncpid + " and (rq >= '"+start.ToString("yyyy-MM-dd")+ "' and rq <= '" + end.ToString("yyyy-MM-dd") + "')"; //SqlParameter[] sqlparms = new SqlParameter[] //{ // new SqlParameter("@ncpid",ncpid) , // new SqlParameter("@yjxzqid",yjxzqid), // new SqlParameter("@start",start), // new SqlParameter("@end",end), //}; using (SqlDataReader reader = SqlHelper.ExecuteReader(sql)) { if (reader.HasRows) { while (reader.Read()) { v_yjdateggjgModel info = new v_yjdateggjgModel(); info.yjxzqid = (int)SqlHelper.FromDbNull(reader["yjxzqid"]); info.ncpid = (int)SqlHelper.FromDbNull(reader["ncpid"]); info.rq = (DateTime)SqlHelper.FromDbNull(reader["rq"]); info.sjttjg = (decimal?)SqlHelper.FromDbNull(reader["sjttjg"]); info.sjpfjg = (decimal?)SqlHelper.FromDbNull(reader["sjpfjg"]); info.sjlsjg = (decimal?)SqlHelper.FromDbNull(reader["sjlsjg"]); info.ycttjg = (decimal?)SqlHelper.FromDbNull(reader["ycttjg"]); info.ycpfjg = (decimal?)SqlHelper.FromDbNull(reader["ycpfjg"]); info.yclsjg = (decimal?)SqlHelper.FromDbNull(reader["yclsjg"]); list.Add(info); } } } return list; }

    EF代码

                    // EF 查询方式一
                    // var data1 = db.v_yjdateggjg.Where(d => d.yjxzqid == yjxzqid && d.ncpid == ncpid && (d.rq >= start && d.rq <= end)).ToList();
                    // EF 查询方式二
                    // string sql = "select *  from v_yjdateggjg where yjxzqid=@yjxzqid and ncpid=@ncpid  and (rq>=@start and rq<=@end)";
                    // var sqlparms = new SqlParameter[] {
                    //     new SqlParameter("@ncpid",ncpid),
                    //     new SqlParameter("@yjxzqid",yjxzqid),
                    //     new SqlParameter("@start",start),
                    //     new SqlParameter("@end",end),
                    //};
                    // var data1 = db.Database.SqlQuery<v_yjdateggjg>(sql, sqlparms).ToList();
    

      

    数据库内部测试

    //sql 参数化查询  1100条数据 3秒
    declare @yjxzqid int =9; declare @ncpid int= 35; declare @start datetime = '2014-5-1'; declare @end datetime='2017-5-1'; select yjxzqid,ncpid,rq,sjttjg,sjpfjg,sjlsjg,ycttjg,ycpfjg,yclsjg from v_yjdateggjg where yjxzqid=@yjxzqid and ncpid=@ncpid and (rq>=@start and rq<=@end) // sql拼接 1100条 1秒 select yjxzqid,ncpid,rq,sjttjg,sjpfjg,sjlsjg,ycttjg,ycpfjg,yclsjg from v_yjdateggjg where yjxzqid=9 and ncpid=35 and (rq>'2014-5-1' and rq<'2017-5-1')

      

    v_yjdateggjg  视图内部sql语句
       SELECT   dbo.v_yjdatejg.yjxzqid, dbo.datalocation.cjdd AS yjxzqname, dbo.v_yjdatejg.ncpid, dbo.products.ncpmc, 
                    dbo.v_yjdatejg.rq, dbo.v_yjdatealljg.ttjg AS sjttjg, dbo.v_yjdatealljg.pfjg AS sjpfjg, dbo.v_yjdatealljg.lsjg AS sjlsjg, 
                    dbo.v_yjdateycjg.ttjg AS ycttjg, dbo.v_yjdateycjg.pfjg AS ycpfjg, dbo.v_yjdateycjg.lsjg AS yclsjg
    FROM      dbo.v_yjdatejg INNER JOIN
                    dbo.datalocation ON dbo.v_yjdatejg.yjxzqid = dbo.datalocation.id INNER JOIN
                    dbo.products ON dbo.v_yjdatejg.ncpid = dbo.products.id LEFT OUTER JOIN
                    dbo.v_yjdateycjg ON dbo.v_yjdatejg.yjxzqid = dbo.v_yjdateycjg.yjxzqid AND 
                    dbo.v_yjdatejg.ncpid = dbo.v_yjdateycjg.ncpid AND dbo.v_yjdatejg.rq = dbo.v_yjdateycjg.ycrq LEFT OUTER JOIN
                    dbo.v_yjdatealljg ON dbo.v_yjdatejg.yjxzqid = dbo.v_yjdatealljg.yjxzqid AND 
                    dbo.v_yjdatejg.ncpid = dbo.v_yjdatealljg.ncpid AND dbo.v_yjdatejg.rq = dbo.v_yjdatealljg.cjrq
    

     

    sqlHelper类

        public static class SqlHelper
        {
            private static readonly string conStr = ConfigurationManager.ConnectionStrings["lyc2ConnString"].ConnectionString;
    
            //insert delete update
            public static int ExecuteNonQuery(string sql, params SqlParameter[] pms)
            {
                using (SqlConnection con = new SqlConnection(conStr))
                {
                    using (SqlCommand cmd = new SqlCommand(sql, con))
                    {
                        if (pms != null)
                        {
                            cmd.Parameters.AddRange(pms);
                        }
                        con.Open();
                        return cmd.ExecuteNonQuery();
                    }
                }
            }
    
            //返回单个值
            public static object ExecuteScalar(string sql, params SqlParameter[] pms)
            {
                using (SqlConnection con = new SqlConnection(conStr))
                {
                    using (SqlCommand cmd = new SqlCommand(sql, con))
                    {
                        if (pms != null)
                        {
                            cmd.Parameters.AddRange(pms);
                        }
                        con.Open();
                        return cmd.ExecuteScalar();
                    }
                }
            }
    
            //执行返回DataReader
            public static SqlDataReader ExecuteReader(string sql,  params SqlParameter[] pms)
            {
                SqlConnection con = new SqlConnection(conStr);
                using (SqlCommand cmd = new SqlCommand(sql, con))
                {
                    if (pms != null)
                    {
                        cmd.Parameters.AddRange(pms);
                    }
                    //con.Open();
                    try
                    {
                        if (con.State == ConnectionState.Closed)
                        {
                            con.Open();
                        }
                        return cmd.ExecuteReader(CommandBehavior.CloseConnection);
                    }
                    catch
                    {
                        con.Close();
                        con.Dispose();
                        throw;
                    }
                }
            }
    
    
            //查询多行 
            public static DataTable ExecuteDataTable(string sql, params SqlParameter[] pms)
            {
                DataTable dt = new DataTable();
                using (SqlDataAdapter adapter = new SqlDataAdapter(sql, conStr))
                {
                    if (pms != null)
                    {
                        adapter.SelectCommand.Parameters.AddRange(pms);
                    }
                    adapter.Fill(dt);
                }
    
                return dt;
            }
    
            /// <summary>
            /// 将DbNull转换成null
            /// </summary>
            /// <param name="obj"></param>
            /// <returns></returns>
            public static object FromDbNull(object obj)
            {
                if (obj == DBNull.Value)
                {
                    return null;
                }
                else
                {
                    return obj;
                }
            }
    
            /// <summary>
            /// 将null转换成DbNull
            /// </summary>
            /// <param name="obj"></param>
            /// <returns></returns>
            public static object ToDbNull(object obj)
            {
                if (obj == null)
                {
                    return DBNull.Value;
                }
                else
                {
                    return obj;
                }
            }
        }
    
    }

     博客园非常蛋疼的说:字数少有150字不能发布的首页。

    答:亲,代码不算数吗?看来博客园的管理已经渐渐思维固话了,越来越像写中学生作文规范。

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  • 原文地址:https://www.cnblogs.com/hao-1234-1234/p/7930602.html
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