Question

我试图创建一个将在数据库中执行的命令，但是当我尝试执行它时，我总是得到相同的错误。

首先，让我们从代码开始，也许有些问题我无法看到：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Data.OleDb;

public partial class ASPX_register : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        try
        {
            string username = Request.Form["username"].Replace("'","''");
            string password = Request.Form["password"].Replace("'", "''");
            string fname = Request.Form["fname"].Replace("'", "''");
            string lname = Request.Form["lname"].Replace("'", "''");
            string email = Request.Form["email"].Replace("'", "''");
            OleDbConnection dbCon = new OleDbConnection();
            OleDbCommand dbCmd = new OleDbCommand();
            String Path = Server.MapPath(@"../App_Data/ShakedDB.mdb;");
            dbCon.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + Path;
            dbCmd.Connection = dbCon;
            OleDbParameter pUser = new OleDbParameter();
            OleDbParameter pPass = new OleDbParameter();
            OleDbParameter pEmail = new OleDbParameter();
            OleDbParameter rDate = new OleDbParameter();
            OleDbParameter pfname = new OleDbParameter();
            OleDbParameter plname = new OleDbParameter();
            pUser.ParameterName = "@Username";
            pUser.Value = username;
            pPass.ParameterName = "@Password";
            pPass.Value = password;
            pfname.ParameterName = "@pfname";
            pfname.Value = fname;
            plname.ParameterName = "@plname";
            plname.Value = lname;
            pEmail.ParameterName = "@Email";
            pEmail.Value = email;
            rDate.ParameterName = "@RDate";
            rDate.Value = DateTime.Now.ToString();
            dbCmd.Parameters.Add(pUser);
            dbCmd.Parameters.Add(pPass);
            dbCmd.Parameters.Add(pEmail);
            dbCmd.Parameters.Add(rDate);
            dbCmd.Parameters.Add(pfname);
            dbCmd.Parameters.Add(plname);
            OleDbDataAdapter dataA = new OleDbDataAdapter(dbCmd);
            dbCmd.CommandText = String.Format("SELECT * FROM Members WHERE username = @Username");
            DataTable dataT = new DataTable();
            dataA.Fill(dataT);
            if (dataT.Rows.Count == 0)
            {
                dbCmd.CommandText = String.Format("INSERT INTO Members (username,[password],[firstName],[lastName],email,registerDate) VALUES (@Username,@Password,@pfname,@plname,@Email,@RDate);");
                dbCon.Open();
                dbCmd.ExecuteNonQuery();
                dbCon.Close();
                Response.Write(" " + fname + " " + lname);
                Response.Write("נרשמת לאתר בהצלחה" + "<br />");
                Response.Write("שם המשתמש שלך הוא:" + username + "<br />");
                Response.Write("הסיסמא שלך היא:" + password + "<br />");
                Response.Write("האימייל שאיתו נרשמת הוא:" + email + "<br />");
                Response.Write("<a href='../ASPX/main.aspx' target='mainFrame'>בחזרה לעמוד הראשי לחץ כאן</a>");
            }
            else
            {
                Response.Write("שם המשתמש הזה כבר תפוס. נסה שם אחר." + "<br />");
                Response.Write("<a href='main.aspx' target='mainFrame'>בחזרה לעמוד הראשי לחץ כאן</a>");
            }
        }
        catch (Exception ex)
        {
            Response.Write(ex);
        }
    }
}

请忽略希伯来语部分，它只是告诉用户他注册了。这是我得到的错误：http://prntscr.com/6gh189 希伯来语部分说＆＃34;表达式数据类型标准不匹配＆＃34;。我想说，如果没有＆＃39; pfname＆＃39;和＆＃39; plname＆＃39;参数，由于某种原因，当我添加它们时会发生此错误。我也尝试写这个＆＃39;插入＆＃39;命令它工作，所以它必须是参数的东西，但我找不到它：

INSERT INTO Members (username,[password],[firstName],[lastName],email,registerDate) VALUES (@Username,@Password,'asdfasdfasdf','asdfasdf',@Email,@RDate);

上面的代码工作，如果我使用它我没有错误。

Answer 1

您正在使用OleDbParameter Constructor (String, Object)重载

DateTime rDate = new DateTime();

rDate = Convert.ToDateTime(DateTime.Now.ToString("MM/dd/yyy hh:mm:ss"));

...

dbCmd.Parameters.Add(rDate);

Answer 2

"SELECT * FROM Members WHERE username = @Username"

变为：

"SELECT * FROM Members WHERE username = ?"

在设置commandtext后移动参数（并将所有内容设置在一行中）：

dbCmd.Parameters.Add("@Username", OleDbType.VarChar, 15).Value = username;

对于插入尝试类似这样的事情：

"INSERT INTO Members (username,[password],[firstName],[lastName],email,registerDate) VALUES (?,?,?,?,?,?);"

cmd.Parameters.AddWithValue("UserName", username);
cmd.Parameters.AddWithValue("Password", password);
etc.

这就是访问dbs的方式。

OleDbCommand的问题，我总是得到同样的错误

2 个答案: