一.Sql注入实例
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp5
{
class Program
{
static void Main(string[] args)
{
//创建连接字符串
SqlConnectionStringBuilder strConn = new SqlConnectionStringBuilder();
strConn.DataSource = "DESKTOP-0MBGCKA\\SQL2016";
strConn.InitialCatalog = "Login";
strConn.IntegratedSecurity = true;
using (SqlConnection conn = new SqlConnection(strConn.ConnectionString))
{
Console.WriteLine("请输入用户名:");
var username = Console.ReadLine();
Console.WriteLine("请输入密码:");
var password = Console.ReadLine();
try
{
string strSql = "select count(*) from users where (name='" + username + "') and (word='" + password + "')";
SqlCommand cmd = new SqlCommand(strSql, conn);
conn.Open();
int row = (int)cmd.ExecuteScalar();
)
{
Console.WriteLine("登陆成功");
}
else
{
Console.WriteLine("登录失败");
}
}
catch (Exception ex)
{
Console.WriteLine("\nError:\n{0}", ex.Message);
}
}
Console.Read();
}
}
}
Sql注入的原理:通过单引号破坏Sql语句的结构,从而使得输入的内容能够被当做Sql语句执行
二.Parameter对象
防止Sql注入的原理:将输入的内容作为字符串处理,不能够破坏Sql语句的结构,使得输入内容不能被当做Sql语句执行
实例:
using System;
using System.Collections.Generic;
using System.Data;
using System.Data.SqlClient;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp5
{
class Program
{
static void Main(string[] args)
{
//创建连接字符串
SqlConnectionStringBuilder strConn = new SqlConnectionStringBuilder();
strConn.DataSource = "DESKTOP-0MBGCKA\\SQL2016";
strConn.InitialCatalog = "Login";
strConn.IntegratedSecurity = true;
using (SqlConnection conn = new SqlConnection(strConn.ConnectionString))
{
Console.WriteLine("请输入用户名:");
var username = Console.ReadLine();
Console.WriteLine("请输入密码:");
var password = Console.ReadLine();
try
{
SqlParameter[] paras = new SqlParameter[] {
),
)
};
paras[].Value = username;
paras[].Value = password;
string strSql = "Select count(*) from users where name= @username and word= @password";
SqlCommand cmd = new SqlCommand(strSql, conn);
cmd.Parameters.Add(paras[]);
cmd.Parameters.Add(paras[]);
conn.Open();
int row = (int)cmd.ExecuteScalar();
)
{
Console.WriteLine("登录成功");
}
else
{
Console.WriteLine("登录失败");
}
}
catch (Exception ex)
{
Console.WriteLine("\nError:\n{0}", ex.Message);
}
}
Console.ReadLine();
}
}
}