Question

我是ASP.net的新手，创建了一个基本的登录页面。我在尝试编译时遇到以下错误：

“System.Data.dll中发生'System.Data.SqlClient.SqlException'类型的异常，但未在用户代码中处理

其他信息：关键字“表格”附近的语法不正确。“

以下是我的代码，有人可以解释一下我在这里做错了吗？

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.SqlClient;
using System.Configuration;



public partial class _Default : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
    if (IsPostBack) {

        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        conn.Open();
        string checkuser = "select count(*) from Table where username = '" + username.Text + "' ";
        SqlCommand com = new SqlCommand(checkuser, conn);
        int temp = Convert.ToInt32(com.ExecuteScalar().ToString());
        if (temp == 1)
        {
            Response.Write("Username Already Exist");
        }
        conn.Close();

    }

}
protected void Button2_Click(object sender, EventArgs e)
{
    try
    {
        SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
        conn.Open();
        string insertQuery = "insert into Table (username, email, password) values (@username, @email, @password)";
        SqlCommand com = new SqlCommand(insertQuery, conn);
        com.Parameters.AddWithValue("@username", username.Text);
        com.Parameters.AddWithValue("@email", emailID.Text);
        com.Parameters.AddWithValue("@password", passwrd.Text);

        com.ExecuteNonQuery();
        Response.Redirect("default3.aspx");
        Response.Write("Your registration is successful");
        conn.Close();
    }
    catch (Exception ex) 
    {
        Response.Write("Error:" + ex.ToString());

    }


    Response.Write("Your form has been submitted");
}
}

Answer 1

Table是T-SQL中的reserved word（出于相当明显的原因）。快速解决方法是明确地附上标识符：

  select count(*) from [Table] where ...

更合适的解决方法是为表提供更有意义的名称。汽车公司没有为其车辆命名Car。它很容易产生混淆。

登录页面中类型为“System.Data.SqlClient.SqlException”的异常

1 个答案: