zoukankan      html  css  js  c++  java
  • 在调用“Fill”前,SelectCommand 属性尚未初始化

    在调用“Fill”前,SelectCommand 属性尚未初始化

    是因为少写了一行代码:

    private readonly string strConnection = System.Configuration.ConfigurationManager.AppSettings["ConnStr"].ToString();
    private void Form1_Load(object sender, EventArgs e)
            {
                string a = "2";
                string sql = " select Date from T_BasicData where userid = '" + a + "'";
                //DataTable DT = Classbase.pubfun.GetSercherGridSource(sql);
                DataTable DT = GetSercherGridSource(sql);
                string b = DT.Rows[0][0].ToString();
                MessageBox.Show(b);
                
    
            }
    public  DataTable GetSercherGridSource(string cmdText)
            {
                DataTable DT = null;
                SqlConnection conn = new SqlConnection(strConnection);
                SqlCommand cmd=conn.CreateCommand();
                SqlDataAdapter adp=new SqlDataAdapter();
                adp.SelectCommand = cmd;
                DataSet ds =new DataSet();
    
                cmd.CommandText=cmdText;
    
                adp = new SqlDataAdapter();
    
                try
                {
                    conn.Open() ;
                    adp.SelectCommand = cmd;//看看有没有这句代码
                    adp.Fill(ds)   ;
                    if (ds != null)
                    {
                        DT = ds.Tables[0];
                    }
                    return DT;
                }
                catch (Exception e)
                {
                    //MessageBox.Show("错误");
                    //MessageBox.Show(string.Format("异常!以下为数据库提示详细错误信息:{0}{1}", Environment.NewLine, cct.CUR_ERROR), "提示");
                    MessageBox.Show(string.Format("异常!以下为数据库提示详细错误信息:{0}{1}", Environment.NewLine, e.Message), "提示");
                    //MessageBox.Show(e.Message);
                    return DT;
                     
                }
            }
  • 相关阅读:
    P1162 填涂颜色
    P1238 走迷宫
    U68364 _GC滑迷宫
    P4783 【模板】矩阵求逆
    P2613 有理数取余
    koa1链接mongodb
    koa的跨域访问
    mongodb 降序
    mongodb 分页(limit)
    mongodb 查询数据
  • 原文地址:https://www.cnblogs.com/wangfeihu/p/5636611.html
Copyright © 2011-2022 走看看