asp.net笔记

一.数据库操作语言

前者用了
sqlconn.Open();
        SqlCommand sqlcom = new SqlCommand();
        sqlcom.Connection = sqlconn;
        sqlcom.CommandText = "select * from customer where personnel_ID='" + this.txtLoginName.Text + "'";
        SqlDataReader read = sqlcom.ExecuteReader();
        read.Read();
后者是
 string sqltest = "select * from customer where personnel_ID='" + this.txtLoginName.Text + "'";
        sqlconn.Open();
        SqlCommand sqlcom = new SqlCommand(sqltest, sqlconn);
        SqlDataReader read = sqlcom.ExecuteReader();
        read.Read();

2.