string sqlStr = @"Data Source=lenovo-e0bed844;Initial Catalog=tese1;Uid=qq;Pwd=123";
using (SqlConnection conn = new SqlConnection(sqlStr))
{
string username=textBox1.Text;
string password=textBox2.Text;
//string sql = string.Format("select count(*) from [qqq] where Username='{0}'and Pwd='{1}'",username,password);
string sql = "select count(*) from [qqq] where Username=@username and Pwd=@password";
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
conn.Open();
SqlParameter sp = new SqlParameter(@username, username);
cmd.Parameters.Add(sp);
cmd.Parameters.Add(new SqlParameter(@password,password));
int n = Convert.ToInt32(cmd.ExecuteScalar());
if (n>0)
{
MessageBox.Show("登录成功");
}
else
{
MessageBox.Show("登录失败");
}
}
}
}
“System.Data.SqlClient.SqlException”类型的未经处理的异常出现在 System.Data.dll 中。其他信息: 必须声明标量变量 "@username"。
希望大手解答一下谢谢
using (SqlConnection conn = new SqlConnection(sqlStr))
{
string username=textBox1.Text;
string password=textBox2.Text;
//string sql = string.Format("select count(*) from [qqq] where Username='{0}'and Pwd='{1}'",username,password);
string sql = "select count(*) from [qqq] where Username=@username and Pwd=@password";
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
conn.Open();
SqlParameter sp = new SqlParameter(@username, username);
cmd.Parameters.Add(sp);
cmd.Parameters.Add(new SqlParameter(@password,password));
int n = Convert.ToInt32(cmd.ExecuteScalar());
if (n>0)
{
MessageBox.Show("登录成功");
}
else
{
MessageBox.Show("登录失败");
}
}
}
}
“System.Data.SqlClient.SqlException”类型的未经处理的异常出现在 System.Data.dll 中。其他信息: 必须声明标量变量 "@username"。
希望大手解答一下谢谢
using (SqlCommand cmd = new SqlCommand(sql, conn))
{
conn.Open();
cmd.Parameters.AddWithValue("@username",username.Trim());
cmd.Parameters.AddWithValue("@password",password.Trim());
int n = Convert.ToInt32(cmd.ExecuteScalar());
......