知道怎么根据数据库的用户名密码来判断是否登录成功 知道怎么根据数据库的用户名密码来判断是否登录成功求代码,或者例子 (加分) 解决方案 » 免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货 bool login=false; string sql ="SELECT 1 from Users where username=@Name and password=@pwd"; using (SqlConnection conn = new SqlConnection("")) { SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.Add("@Name", SqlDbType.VarChar); cmd.Parameters["@name"].Value = "张三"; cmd.Parameters.Add("@pwd", SqlDbType.VarChar); cmd.Parameters["@pwd"].Value = "123"; try { conn.Open(); login = (Int32)cmd.ExecuteScalar()>0; } catch (Exception ex) { Console.WriteLine(ex.Message); } } vs2005中的aspnetdb bool login=false; string sql ="SELECT 1 from Users where username=@Name and password=@pwd"; using (SqlConnection conn = new SqlConnection("")) { SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.Add("@Name", SqlDbType.VarChar); cmd.Parameters["@name"].Value = "张三"; cmd.Parameters.Add("@pwd", SqlDbType.VarChar); cmd.Parameters["@pwd"].Value = "123"; try { conn.Open(); login = (Int32)cmd.ExecuteScalar()>0; } catch (Exception ex) { Console.WriteLine(ex.Message); } } bool login=false; string sql ="SELECT 1 from Users where username=@Name and password=@pwd"; using (SqlConnection conn = new SqlConnection("")) { SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.Add("@Name", SqlDbType.VarChar); cmd.Parameters["@name"].Value = "张三"; cmd.Parameters.Add("@pwd", SqlDbType.VarChar); cmd.Parameters["@pwd"].Value = "123"; try { conn.Open(); login = (Int32)cmd.ExecuteScalar()>0; } catch (Exception ex) { Console.WriteLine(ex.Message); } } string sql = "select * from users where username='" + txtUserName.Text + "' and password='" + txtPassword.Text+ "'"; if (db.SelectSql(sql).Tables[0].Rows.Count > 0) { ClientScript.RegisterStartupScript(Page.GetType(), "", "<script>alert('登陆成功!')</script>"); } else { ClientScript.RegisterStartupScript(Page.GetType(), "", "<script>alert('用户名或密码输入有误!')</script>"); } WINFORM 的, SQL 2005 bool login=false; string sql ="SELECT 1 from Users where username=@Name and password=@pwd"; using (SqlConnection conn = new SqlConnection("")) { SqlCommand cmd = new SqlCommand(sql, conn); cmd.Parameters.Add("@Name", SqlDbType.VarChar); cmd.Parameters["@name"].Value = "张三"; cmd.Parameters.Add("@pwd", SqlDbType.VarChar); cmd.Parameters["@pwd"].Value = "123"; try { conn.Open(); login = (Int32)cmd.ExecuteScalar()>0; } catch (Exception ex) { Console.WriteLine(ex.Message); } }以上代码就可以了。我试过。 奇怪的dateTimePicker 每隔5秒执行一次函数,执行10分钟,提示错误 连接不上 exchange server C# vs2008 winform 怎么读取 APP.CONFIG 里的connectionString值 ?谢谢!内容如下: 在一个窗体中调用另一个窗体的问题 有个C#的问题向大家请教 页面调用自定义控件,给linkbutton赋值问题 想做一个代码生成器,但不知道怎么入手 请教个oracle事务处理的问题 获取图片 关于套接字接收数据的问题 C#做Windows服务问题,服务启动时报<服务并未及时响应启动或控制请求>
bool login=false;
string sql ="SELECT 1 from Users where username=@Name and password=@pwd";
using (SqlConnection conn = new SqlConnection(""))
{
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add("@Name", SqlDbType.VarChar);
cmd.Parameters["@name"].Value = "张三";
cmd.Parameters.Add("@pwd", SqlDbType.VarChar);
cmd.Parameters["@pwd"].Value = "123";
try
{
conn.Open();
login = (Int32)cmd.ExecuteScalar()>0;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
string sql ="SELECT 1 from Users where username=@Name and password=@pwd";
using (SqlConnection conn = new SqlConnection(""))
{
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add("@Name", SqlDbType.VarChar);
cmd.Parameters["@name"].Value = "张三";
cmd.Parameters.Add("@pwd", SqlDbType.VarChar);
cmd.Parameters["@pwd"].Value = "123";
try
{
conn.Open();
login = (Int32)cmd.ExecuteScalar()>0;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
string sql ="SELECT 1 from Users where username=@Name and password=@pwd";
using (SqlConnection conn = new SqlConnection(""))
{
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add("@Name", SqlDbType.VarChar);
cmd.Parameters["@name"].Value = "张三";
cmd.Parameters.Add("@pwd", SqlDbType.VarChar);
cmd.Parameters["@pwd"].Value = "123";
try
{
conn.Open();
login = (Int32)cmd.ExecuteScalar()>0;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
if (db.SelectSql(sql).Tables[0].Rows.Count > 0)
{
ClientScript.RegisterStartupScript(Page.GetType(), "", "<script>alert('登陆成功!')</script>"); }
else
{
ClientScript.RegisterStartupScript(Page.GetType(), "", "<script>alert('用户名或密码输入有误!')</script>");
}
string sql ="SELECT 1 from Users where username=@Name and password=@pwd";
using (SqlConnection conn = new SqlConnection(""))
{
SqlCommand cmd = new SqlCommand(sql, conn);
cmd.Parameters.Add("@Name", SqlDbType.VarChar);
cmd.Parameters["@name"].Value = "张三";
cmd.Parameters.Add("@pwd", SqlDbType.VarChar);
cmd.Parameters["@pwd"].Value = "123";
try
{
conn.Open();
login = (Int32)cmd.ExecuteScalar()>0;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
以上代码就可以了。我试过。