Question

asp.net (c#) 连接数据库 验证用户登陆

比如有个登陆表（logoin），2个列admin和pwd
最好给出代码解释

Answer 1

private void btnLogin_Click(object sender, EventArgs e)
{
string constr = "Data Source=SQL2000;Initial Catalog=login;Integrated Security=True";//你要与自己的数据库建立联系，我这边用的是windows验证
mysqlconnection = new SqlConnection(constr);
mysqlconnection.Open();
SqlCommand cmd = new SqlCommand("SELECT * FROM user WHERE

name='" + this.txtName.Text + "' and pass='" + this.txtPasswd.Text +

"'",mysqlconnection);
string t = cmd.ExecuteScalar().ToString();
cmd.Connection.Close();
if (t!="0")
{
Server.Transfer("right.aspx?Feedback="...."");//跳到right.aspx;
}
else
{
Server.Transfer("wrong.aspx?Feedback="..."");//跳到wrong.aspx;
}

}

Answer 2

一般是这样做的：
页面上输入用户名（user）和密码（pass），根据输入去（logoin）中检索：select count(*) from logoin where admin=user and pwd=pass

判断count(*)>0,正确，否则不正确
，还有什么不明白的？

Answer 3

string connstr = "server=.;uid=sa;pwd=sa;database=sc";
SqlConnection sconn = new SqlConnection();
SqlCommand scmd = new SqlCommand();
DataSet ds = new DataSet();
protected void Login_Click(object sender, EventArgs e)
{

string UserName = user_TextBox.Text.Trim();
string Password = password_TextBox.Text.Trim();
scmd.CommandText = "select * from logoin where admin='" + UserName + "' and pwd='" + Password + "'";
sconn.ConnectionString = connstr;
scmd.Connection = sconn;
sconn.Open();
SqlDataReader dr = scmd.ExecuteReader();
if (dr.Read())
{
Session["UserName"] = dr["admin"].ToString().Trim();
Session["Password"] = dr["pwd"].ToString().Trim();
Response.Redirect("Index1.aspx");//登陆成功跳转页面
}

else
Label1.Text = "用户名和密码无效,请重试！！！！";
}
我感觉你应该都能看懂吧，你如果学过asp.net