Question

我收到此错误'nvarchar'附近的语法不正确。必须声明标量变量“@”。我正在使用下面提到的代码。这里SACALOGIN.MDF是数据库名称admin_login是表名。用户名和密码是表格列，admin1.aspx是另一个网页...请帮忙，因为它让我头疼......

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Text;
using System.Web.Configuration.Common;
using System.Web.Configuration.Internal;
using System.Data.SqlClient;
using System.Data;
using System.Web.Configuration;
public partial class Login : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{

}
   protected void btnSubmit_Click(object sender, EventArgs e)
{

    SqlConnection cn=new SqlConnection();
    cn.ConnectionString = 
      WebConfigurationManager.ConnectionStrings["SACALOGIN.MDF"].ConnectionString;
    cn.Open();
    string sql="Select * from admin_login where ID=@[ID]";
    SqlCommand cmd=new SqlCommand(sql,cn);
    cmd.Parameters.AddWithValue("@[User-Name]",txtUserName.Text);
    cmd.Parameters.AddWithValue("@Password",txtPWD.Text);
    SqlDataReader dr=cmd.ExecuteReader();
    bool found=false;
    if(dr.Read())
    {
        found=true;
        cn.Close();
        if(found)
        {
            Response.Redirect("admin1.aspx");
           }
        else 
            lblMessage.Text="Sorry! Invalid User Id.";
    }

}
}

Answer 1

您使用的是“ID”参数，但您在命令中添加的唯一参数是“@ user-name”和“@Password”。尝试替换：

string sql="Select * from admin_login where ID=@[ID]";
SqlCommand cmd=new SqlCommand(sql,cn);
cmd.Parameters.AddWithValue("@[User-Name]",txtUserName.Text);
cmd.Parameters.AddWithValue("@Password",txtPWD.Text);

by：

string sql="Select * from admin_login where [ID]=@ID";
SqlCommand cmd=new SqlCommand(sql,cn);
cmd.Parameters.Add("@ID", SqlDbType.Int);
cmd.Parameters["@ID"].Value = userID;

当然，无论你的用户名变量是什么，都要用最后的'userID'替换......

Answer 2

我认为你的代码不会起作用。

它应该是这样的

SqlConnection cn=new SqlConnection();
cn.ConnectionString =                                                                                                  W         WebConfigurationManager.ConnectionStrings["SACALOGIN.MDF"].ConnectionString;
cn.Open();
string sql="Select * from admin_login where [User-Name] = @Username and Password= @Password";
SqlCommand cmd=new SqlCommand(sql,cn);
cmd.Parameters.AddWithValue("@Username",txtUserName.Text);
cmd.Parameters.AddWithValue("@Password",txtPWD.Text);
SqlDataReader dr=cmd.ExecuteReader();
bool found=false;

如何删除错误＆nbspchar＆＃39;附近的语法不正确。必须声明标量变量＆＃34; @＆＃34;

2 个答案: