附加信息：将nvarchar值'label'转换为数据类型int时转换失败。 [英] Additional information: conversion failed when converting the nvarchar value 'label' to data type int.

问题描述

< sqlconnection con =newmode =hold> con.Open（）;

SqlCommand cmd = new SqlCommand（update tblRegi set firstname = @ Firstname，Lastname = @ Lastname，Username = @ Username，Password = @ Password，Repassword = @ Repassword，Gen​​der = @性别，爱好= @爱好，国家= @国家，州= @州，城市= @城市，Secrtyque = @ Secrtyque，Secrtyans = @ Secrtyans，其中id = @ id，con）;

cmd.Parameters.AddWithValue（@ Firstname，TxtFirstname.Text）;

cmd.Parameters.AddWithValue（@ Lastname，TxtLastname.Text）;

cmd .Parameters.AddWithValue（@ Username，TxtUsername.Text）;

cmd.Parameters.AddWithValue（@ Password，TxtPasswword.Text）;

cmd.Parameters .AddWithValue（@ Repassword，TxtRePassword.Text）;

cmd.Parameters.AddWithValue（@ Gender，RbtnGender.SelectedValue）;

cmd.Parameters.AddWithValue （@Hobbies，ChbxHobbies.SelectedValue）;

cmd.Parameters.AddWithValue（@ Country，DrpCountry.SelectedV alue）;

cmd.Parameters.AddWithValue（@ State，DrpState.SelectedValue）;

cmd.Parameters.AddWithValue（@ City，DrpCity.SelectedValue） ;

cmd.Parameters.AddWithValue（@ Secrtyque，DrpScQue.SelectedValue）;

cmd.Parameters.AddWithValue（@ Secrtyans，TxtScAns.Text）;

cmd.Parameters.AddWithValue（@ id，Label1.Text）;

cmd.ExecuteNonQuery（）;

con.Close（） ;



我尝试了什么：



我做的是什么解决这个错误

<sqlconnection con="new" mode="hold"> con.Open();
SqlCommand cmd = new SqlCommand("update tblRegi set Firstname=@Firstname,Lastname=@Lastname,Username=@Username,Password=@Password,Repassword=@Repassword,Gender=@Gender,Hobbies=@Hobbies,Country=@Country,State=@State,City=@City,Secrtyque=@Secrtyque,Secrtyans=@Secrtyans where id=@id", con);
cmd.Parameters.AddWithValue("@Firstname", TxtFirstname.Text);
cmd.Parameters.AddWithValue("@Lastname", TxtLastname.Text);
cmd.Parameters.AddWithValue("@Username", TxtUsername.Text);
cmd.Parameters.AddWithValue("@Password", TxtPasswword.Text);
cmd.Parameters.AddWithValue("@Repassword", TxtRePassword.Text);
cmd.Parameters.AddWithValue("@Gender", RbtnGender.SelectedValue);
cmd.Parameters.AddWithValue("@Hobbies", ChbxHobbies.SelectedValue);
cmd.Parameters.AddWithValue("@Country", DrpCountry.SelectedValue);
cmd.Parameters.AddWithValue("@State", DrpState.SelectedValue);
cmd.Parameters.AddWithValue("@City", DrpCity.SelectedValue);
cmd.Parameters.AddWithValue("@Secrtyque", DrpScQue.SelectedValue);
cmd.Parameters.AddWithValue("@Secrtyans", TxtScAns.Text);
cmd.Parameters.AddWithValue("@id",Label1.Text);
cmd.ExecuteNonQuery();
con.Close();

What I have tried:

what i do that solve this error

推荐答案

就像C＃有严格的打字而你不能这样做：

Just like C# has strict typing and you can't do this:

int id = "label";

..您的数据库也是严格打字，你不能将一个字符串（在这种情况下显然包含label）分配给一个列机智ha类型的int或直接比较它们。



最有可能是这一行：

..your database as strict typing as well and you can't assign a string (in this case apparently containing "label") to a column with a type of int or compare them directly.

Most probably it's this line:

cmd.Parameters.AddWithValue("@id",Label1.Text);

理论上你应该使用 Int32.TryParse（..） [ ^ ]到将字符串解析为整数。但首先你需要注意标签的文本实际显示一个有效的整数而不是标签。否则.TryParse（..）将失败。



其他比那样：你似乎将密码作为纯文本存储在数据库中。您可能想要阅读这些内容：

初学者指导存储密码的安全方式 [ ^ ]

简单安全密码认证 [ ^ ]

Theoretically you should use Int32.TryParse(..)[^] to parse the string into an integer. But first you need to take care that the text of the label actually shows a valid integer and not "label" otherwise .TryParse(..) will fail.

Other than that: It appears you're storing passwords as plain text in your database. You might want to give these a read:
Beginners guide to a secure way of storing passwords[^]
Secure Password Authentication Explained Simply[^]

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