初学者求救啊！Visual studio2010怎么用代码连上SQL server 数据库呢？

[ljb5460]

我想做个登录界面 有哪位大哥大姐 能帮帮我 。。谢谢了

[壁橱里的老王]

SqlConnectionStringBuilder b = new SqlConnectionStringBuilder();
b.DataSource = @".";//本地数据库
b.IntegratedSecurity = true;
b.InitialCatalog = "northwind";//数据库名
String conStr = b.ConnectionString;
SqlConnection con = new SqlConnection(conStr);
string sql=""//sql 脚本
sqlcommand cmd= new sqlcommand(sql,con);
con.open();
int result=cmd.executescalar();
cmd.close
if(result)//进行登录处理
response.redirect()
else
alert("<script>**failed**</script>")

[我爱小土豆]

data source=.;initial catalog=数据库名;integrated security=true

这是集成验证，数据库没有密码的情况下。

[lee3217813]

这··，还是自己先学吧，一点不知道的话就不是几句话能说明白的

[tan598121925]

找几个登录的例子看看就明白了[Quote=引用 7 楼 lee3217813 的回复:]

这··，还是自己先学吧，一点不知道的话就不是几句话能说明白的
[/Quote]

[n_dota]

<table align="center" cellpadding="0" cellspacing="0" class="style1" 
    style="height: 189px; width: 360px">
            <tr>
                <td class="style4">
                    用  户  名：</td>
                <td class="style3">
                    <asp:TextBox ID="txtUserName" runat="server" Width="150px"></asp:TextBox>
                </td>
                <td>
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator1" runat="server" 
                        ControlToValidate="txtUserName" Display="Dynamic" ErrorMessage="*"></asp:RequiredFieldValidator>
                </td>
            </tr>
            <tr>
                <td class="style4">
                    密        码：</td>
                <td class="style3">
                    <asp:TextBox ID="txtPwd" runat="server" TextMode="Password" Width="150px"></asp:TextBox>
                </td>
                <td>
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator2" runat="server" 
                        ControlToValidate="txtPwd" Display="Dynamic" ErrorMessage="*"></asp:RequiredFieldValidator>
                </td>
            </tr>
            <tr>
                <td class="style4">
                    安全问题：</td>
                <td class="style3">
                    <asp:TextBox ID="txtquestion" runat="server" Width="150px"></asp:TextBox>
                </td>
                <td>
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator3" runat="server" 
                        ControlToValidate="txtquestion" Display="Dynamic" ErrorMessage="*"></asp:RequiredFieldValidator>
                </td>
            </tr>
            <tr>
                <td class="style4">
                    提示答案：</td>
                <td class="style3">
                    <asp:TextBox ID="txtresult" runat="server" Width="150px"></asp:TextBox>
                </td>
                <td>
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator4" runat="server" 
                        ControlToValidate="txtresult" Display="Dynamic" ErrorMessage="*"></asp:RequiredFieldValidator>
                </td>
            </tr>
            <tr>
                <td class="style4">
                    电子邮件：</td>
                <td class="style3">
                    <asp:TextBox ID="txtEmail" runat="server" Width="150px"></asp:TextBox>
                </td>
                <td valign="middle">
                    <asp:RequiredFieldValidator ID="RequiredFieldValidator5" runat="server" 
                        ControlToValidate="txtEmail" Display="Dynamic" ErrorMessage="*"></asp:RequiredFieldValidator>
                    <asp:RegularExpressionValidator ID="RegularExpressionValidator1" runat="server" 
                        BorderStyle="Solid" BorderWidth="1px" ControlToValidate="txtEmail" 
                        Display="Dynamic" ErrorMessage="邮件地址错误" Font-Overline="False" Font-Size="10pt" 
                        ValidationExpression="\w+([-+.']\w+)*@\w+([-.]\w+)*\.\w+([-.]\w+)*"></asp:RegularExpressionValidator>
                </td>
            </tr>
            <tr>
                <td class="style4">
                     </td>
                <td colspan="2">
                    <asp:Button ID="Button1" runat="server" Text="注册" onclick="Button1_Click" />
 
                    <asp:Button ID="Button2" runat="server" Text="重置" onclick="Button2_Click" />
                </td>
            </tr>
        </table>

using System;
using System.Collections;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
using System.Data.SqlClient;
public partial class login : System.Web.UI.UserControl
{
    protected void Page_Load(object sender, EventArgs e)
    {

    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        txtEmail.Text = "";
        txtPwd.Text = "";
        txtquestion.Text = "";
        txtresult.Text = "";
        txtUserName.Text = "";
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        string sqlstr = System.Configuration.ConfigurationManager.AppSettings["con"].ToString();
        SqlConnection conn = new SqlConnection(sqlstr);
        conn.Open();
        SqlCommand cmd = new SqlCommand();
        cmd.Connection = conn;
        cmd.CommandType = CommandType.Text;
        cmd.CommandText = "select count(*) from Tb_Login where UseName='"+txtUserName.Text.Trim()+"'";
        int flag=int.Parse(cmd.ExecuteScalar().ToString());
        if (flag > 0)
        {
            Page.ClientScript.RegisterStartupScript(this.Parent.GetType(), "", "alert('该用户名已经存在');", true);
        }
        else
        {
            cmd.CommandText = "insert into Tb_Login(UseName,UsePassword,UserEmail,Question,UserKey) values ('" + txtUserName.Text + "','" + txtPwd.Text + "','" + txtEmail.Text + "','" + txtquestion.Text + "','" + txtresult.Text + "')";
            if(cmd.ExecuteNonQuery()>0)
            {
                Page.ClientScript.RegisterStartupScript(this.Parent.GetType(), "", "alert('用户注册成功');", true);
            }
            else
            {
                Page.ClientScript.RegisterStartupScript(this.Parent.GetType(), "", "alert('用户注册失败');", true);
            }
        }
        conn.Close();
    }
}

[porschev]

连接字符串 http://www.connectionstrings.com/

SqlConnection

[ljb5460]

[Quote=引用 9 楼 n_dota 的回复:]
HTML code
<table align="center" cellpadding="0" cellspacing="0" class="style1"
style="height: 189px; width: 360px">
<tr>
<td class="style4">
用……
[/Quote]
弄好了 谢谢大家啊 ~

[myhope88]

.net连接数据库都不多呀，虽然开发环境不一样

[IT-Style]

Ado.net连接SqlServer的几个重要类,SqlConnection,SqlCommand,SqlDataAdapter,SqlDataReader...

[ljb5460]

[Quote=引用 1 楼 softkexin 的回复:]
Ado.net连接SqlServer的几个重要类,SqlConnection,SqlCommand,SqlDataAdapter,SqlDataReader...
[/Quote] 可以具体给个例子么？

[01看世界]

中文解释塞进去了

Sqlconnection conn = new Sqlconnection(数据的连接字符串);
conn.Open();
string sqlstr ="SQL语句";
Sqlcommand cmd = new Sqlcommand(sqlstr,conn);
再用SqlDataReader

[傍山人家]

9楼您好，这个代码 抛出异常：未将对象引用设置到对象的实例。 行数就30行： string sqlstr = System.Configuration.ConfigurationManager.AppSettings["con"].ToString(); 有解决办法吗