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;
            }
        }