Question

using System;
using System.Collections.Generic;
using System.Web;
using System.Data;
using System.Data.SqlClient;
using System.Configuration;

/// <summary>
/// Summary description for Transaction
/// </summary>
public class Transaction
{
    private string connStr = ConfigurationManager.ConnectionStrings["airmazin"].ConnectionString;
    private string _TransactionID;
    private string _OfferId;
    private string _UserName;
    private string _Image;
    private string _ProductName;
    private decimal _ProductPrice;

    public Transaction()
    {
        this.TransactionID = null;
        this.OfferId = null;
        this.UserName = null;
        this.Image = null;
        this.ProductName = null;
        this.ProductPrice = 0;
        //
        // TODO: Add constructor logic here
        //
    }

    public Transaction(string p_TransactionID, string p_OfferId, string p_UserName, string p_Image, string p_ProductName, decimal p_ProductPrice)
    {
        this.TransactionID = p_TransactionID;
        this.OfferId = p_OfferId;
        this.UserName = p_UserName;
        this.Image = p_Image;
        this.ProductName = p_ProductName;
        this.ProductPrice = p_ProductPrice;
    }

    private string TransactionID
    {
        get { return _TransactionID; }
        set { _TransactionID = value; }
    }
    private string OfferId
    {
        get { return _OfferId; }
        set { _OfferId = value; }
    }
    private string UserName
    {
        get { return _UserName; }
        set { _UserName = value; }
    }
    private string Image
    {
        get { return _Image; }
        set { _Image = value; }
    }
    private string ProductName
    {
        get { return _TransactionID; }
        set { _ProductName = value; }
    }
    private decimal ProductPrice
    {
        get { return _ProductPrice; }
        set { _ProductPrice = value; }
    }  //getter and setter
    public Transaction getProductTransaction(string p_UserName)
    {
        Transaction prodDetail = null;
        string tran_ID, offer_ID, user, Prod_Image, prod_Name;
        decimal prod_Price;
        SqlConnection conn = new SqlConnection(connStr);
        string queryStr = "SELECT * FROM Transaction WHERE UserName = @user";
       // think the naming convention is wrong 
        SqlCommand cmd = new SqlCommand(queryStr, conn);
        cmd.Parameters.AddWithValue("@user", p_UserName);
        conn.Open();
        SqlDataReader dr = cmd.ExecuteReader();
        if (dr.Read())
        {
            tran_ID = dr["TransactionID"].ToString();
            offer_ID = dr["OfferId"].ToString();
            user = dr["UserName"].ToString();
            Prod_Image = dr["Image"].ToString();
            prod_Name = dr["ProductName"].ToString();
            prod_Price = decimal.Parse(dr["ProductPrice"].ToString());
            prodDetail = new Transaction(tran_ID, offer_ID, user, Prod_Image, prod_Name, prod_Price);
        }
        else
        {
            prodDetail = null;
        }
        conn.Close();
        dr.Close();
        dr.Dispose();
        return prodDetail;

    }

对于sql不确定。刚开始编程，目前是一名学生。遇到此错误，提示附近关键字“事务”。命名惯例可能是错误的，可能需要一些帮助。想要在aspx页面上显示交易记录，所以我正在执行getProductTransaction（）{}方法，但是似乎有问题

编辑（通过评论）

现在我希望它显示交易列表，而不是单个交易

Answer 1

由于表名称“ Transaction”是关键字，可能会出现问题。您可以尝试将其作为查询：

string queryStr = "SELECT * FROM [Transaction] WHERE UserName = @user";

Answer 2

评论和解释是内联的。 using块可确保IDisposable对象被关闭并正确处理，即使有错误也是如此。

public class Transaction
    {
        private string connStr = ConfigurationManager.ConnectionStrings["airmazin"].ConnectionString;
        public Transaction() { }
        //Auto-Implemented Properties in C# 3 and later
        //The standard get and set are written for you by the compiler
        //Also the compiler writes the private fields where the data is stored
        public string TransactionID { get; set; }
        public string OfferId { get; set; }
        public string UserName { get; set; }
        public string Image { get; set; }
        public string ProductName { get; set; }
        public decimal ProductPrice { get; set; }
        //changed the function to return a list
        public List<Transaction> getProductTransaction(string p_UserName)
        {
            List<Transaction> lst = new List<Transaction>();
            using (SqlConnection conn = new SqlConnection(connStr))
            { 
                string queryStr = "SELECT * FROM [Transaction] WHERE UserName = @user";
                using (SqlCommand cmd = new SqlCommand(queryStr, conn))
                { 
                    cmd.Parameters.AddWithValue("@user", p_UserName);
                    conn.Open();
                    using (SqlDataReader dr = cmd.ExecuteReader())
                    { 

                        if (dr.HasRows)
                            while (dr.Read())
                                //This loop keeps adding records to the list as long as there are records to read
                            {
                                Transaction prodDetail = new Transaction();
                                prodDetail.TransactionID= dr["TransactionID"].ToString();
                                prodDetail.OfferId = dr["OfferId"].ToString();
                                prodDetail.UserName = dr["UserName"].ToString();
                                prodDetail.Image = dr["Image"].ToString();
                                prodDetail.ProductName = dr["ProductName"].ToString();
                                prodDetail.ProductPrice = decimal.Parse(dr["ProductPrice"].ToString());
                                lst.Add(prodDetail);
                            }
                        else
                        {
                            lst = null;
                        }
                    }
                }
            }
            return lst;
        }
    }

用户代码未处理SqlException，关键字事务附近的语法不正确

2 个答案: