偶也不知道算不算，反正我自己隨時寫的用，很粗淺的，適合跟我一樣的新手收藏，指不定就用得上呢！

一組是我這兩天寫留言本的
另組是以前VS2003寫投票用的

高手看見的話，麻煩把好的解決方案說下，謝謝哦！！新手的話，共同學習了！！

--------下面是我最近寫個留言本用的------------
    public static OleDbConnection con()
    {//數據庫連接類
        OleDbConnection con = new OleDbConnection(ConfigurationManager.ConnectionStrings["book"].ConnectionString);
        return con;
    }
    public static bool insert(string que)
    { //根據傳進來的ＳＱＬ語句執行插入操作
        OleDbConnection con = odb.con();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(que,con);
        int count = Convert.ToInt32(cmd.ExecuteNonQuery());
        if (count > 0)
            return true;
        else
            return false;
        con.Close();
    }
    public static DataTable ds(string que)
    {//返回一個裝載了SQL制定留言的數據表，
        OleDbConnection con = odb.con();
        OleDbDataAdapter oda = new OleDbDataAdapter();
        oda.SelectCommand=new OleDbCommand(que,con);
        DataSet ds = new DataSet();
        oda.Fill(ds,"thc");
        return ds.Tables["thc"];
        con.Close();
    }
    public static bool img(string que)
    {//根據傳來的條件查詢該項是否有內容，有就返回true
        OleDbConnection con = odb.con();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(que,con);
        if (cmd.ExecuteScalar().ToString() != "")
            return true;
        else
            return false;
        con.Close();
    }
    public static string scr(string que)
    {//同樣是根據傳來的ＳＱＬ語句返回一個字段的值，我不太喜歡把ＳＱＬ語句做在內中，感覺不靈活
        OleDbConnection con = odb.con();
        con.Open();
        OleDbCommand cmd = new OleDbCommand(que,con);
        return cmd.ExecuteScalar().ToString();
    }

-----------下面是以前2003的時候用的----------
public static SqlConnection con()
        {//（靜態）初始化鏈接，因為數據庫路徑在web.config文件里面，所以這里返回的是哪個字符串,這是ＶＳ２００３的數據庫連接初始實例
            SqlConnection con=new SqlConnection(System.Configuration.ConfigurationSettings.AppSettings["con"]);
            return con;
        }
        public static bool chklog(string name,string pwd)
        {//判斷數據庫里是否存在這個用戶，返回真或則假
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand("select count(*) from admin where name='"+name+"' and pwd='"+pwd+"'",con);
            int count=Convert.ToInt32(cmd.ExecuteScalar());
            if(count>0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        public static string chkqx(string name,string pwd)
        {//判斷當前用戶的權限，并返回權限
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand("select qx from admin where name='"+name+"' and pwd='"+pwd+"'",con);
            string qx=Convert.ToString(cmd.ExecuteScalar());
            return qx;
        }
        public static DataTable fill(string query)
        {//根據傳來的ＳＱＬ語句查詢出數據并填充一個表給查詢對象
            SqlConnection con=db.con();
            SqlDataAdapter sda=new SqlDataAdapter();
            sda.SelectCommand=new SqlCommand(query,con);
            DataSet ds=new DataSet();
            sda.Fill(ds,"vote");
            return ds.Tables["vote"];
          
        }
        public static string title(int ID)
        {//(靜態)根據傳來的ID返回該投票項標題
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand("select xiang from votemaster where id='"+ID+"'",con);
            return cmd.ExecuteScalar().ToString();
        }
        public static void delete(string query)
        {//(靜態)執行指定的刪除行為
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);
            cmd.ExecuteNonQuery();
        }
        public static void update(string query)
        {//(靜態)執行指定的更新行為
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);
            cmd.ExecuteNonQuery();
        }
        public static int cid(string query)
        {//（靜態）根據執行的語句查詢出當前數據庫最新的一個ＩＤ
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);
            int id=Convert.ToInt32(cmd.ExecuteScalar());
            return id;
        }
        public static bool insert(string query)
        {//插入操作
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);           
            int count=Convert.ToInt32(cmd.ExecuteNonQuery());
            if(count>0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
        public static int typ(int id)
        {//根據出來的ＩＤ，返回該ＩＤ所屬于的投票屬于多選還是單選
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand("select typ from votemaster where id='"+id+"'",con);
            int typ=Convert.ToInt32(cmd.ExecuteScalar());
            return typ;
        }
        public static string count()
        {//返回總訪問人數
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand("select coun from countline",con);
            string count=cmd.ExecuteScalar().ToString();
            return count;
        }
        public static string rengyi(string query)
        {//查詢任意單字段，返回字段值的一個靜態方法
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);
            return cmd.ExecuteScalar().ToString();
        }
        public static bool vlog(string query)
        {//查詢任意單字段,返回真與假的一個靜態方法
            SqlConnection con=db.con();
            con.Open();
            SqlCommand cmd=new SqlCommand(query,con);
            int count=Convert.ToInt32(cmd.ExecuteScalar());
            if(count>0)
            {
                return true;
            }
            else
            {
                return false;
            }
        }
http://thcjp.VEVb.com/archive/2006/06/18/428775.html