PHP查询数据库生成json

首先，用到了我收藏的db.class.php文件

文件：db.class.php

<?php
//MySQL、MySQLi、SQLite 三合一数据库操作类
if(!defined('IN_CRONLITE'))exit();

$nomysqli=true;

if(defined('SQLITE')==true){
    class DB {
        var $link = null;

        function __construct($db_file){
            global $siteurl;
        $this->link = new PDO('sqlite:'.ROOT.'includes/sqlite/'.$db_file.'.db');
        if (!$this->link) die('Connection Sqlite failed.\n');
        return true;
        }

        function fetch($q){
            return $q->fetch();
        }
        function get_row($q){
            $sth = $this->link->query($q);
            return $sth->fetch();
        }
        function count($q){
            $sth = $this->link->query($q);
            return $sth->fetchColumn();
        }
        function query($q){
            return $this->result=$this->link->query($q);
        }
        function affected(){
            return $this->result->rowCount();
        }
        function error(){
            $error = $this->link->errorInfo();
            return '['.$error[1].'] '.$error[2];
        }
    }
}
elseif(extension_loaded('mysqli') && $nomysqli==false) {
    class DB {
        var $link = null;

        function __construct($db_host,$db_user,$db_pass,$db_name,$db_port){

            $this->link = mysqli_connect($db_host, $db_user, $db_pass, $db_name, $db_port);

            if (!$this->link) die('Connect Error (' . mysqli_connect_errno() . ') '.mysqli_connect_error());

            //mysqli_select_db($this->link, $db_name) or die(mysqli_error($this->link));

mysqli_query($this->link,"set sql_mode = ''");
 //字符转换，读库
mysqli_query($this->link,"set character set 'utf8'");
//写库
mysqli_query($this->link,"set names 'utf8'"); 
    return true;
    }
        function fetch($q){
            return mysqli_fetch_assoc($q);
        }
        function get_row($q){
            $result = mysqli_query($this->link,$q);
            return mysqli_fetch_assoc($result);
        }
        function count($q){
            $result = mysqli_query($this->link,$q);
            $count = mysqli_fetch_array($result);
            return $count[0];
        }
        function query($q){
            return mysqli_query($this->link,$q);
        }
        function escape($str){
            return mysqli_real_escape_string($this->link,$str);
        }
        function insert($q){
            if(mysqli_query($this->link,$q))
                return mysqli_insert_id($this->link); 
            return false;
        }
        function affected(){
            return mysqli_affected_rows($this->link);
        }
        function insert_array($table,$array){
            $q = "INSERT INTO `$table`";
            $q .=" (`".implode("`,`",array_keys($array))."`) ";
            $q .=" VALUES ('".implode("','",array_values($array))."') ";

            if(mysqli_query($this->link,$q))
                return mysqli_insert_id($this->link);
            return false;
        }
        function error(){
            $error = mysqli_error($this->link);
            $errno = mysqli_errno($this->link);
            return '['.$errno.'] '.$error;
        }
        function close(){
            $q = mysqli_close($this->link);
            return $q;
        }
    }
} else { // we use the old mysql
    class DB {
        var $link = null;

        function __construct($db_host,$db_user,$db_pass,$db_name,$db_port){

        $this->link = @mysql_connect($db_host.':'.$db_port, $db_user, $db_pass);

        if (!$this->link) die('Connect Error (' . mysql_errno() . ') '.mysql_error());

            mysql_select_db($db_name, $this->link) or die(mysql_error($this->link));

mysql_query("set sql_mode = ''");
//字符转换，读库
mysql_query("set character set 'utf8'");
//写库
mysql_query("set names 'utf8'"); 

    return true;
        }
        function fetch($q){
            return mysql_fetch_assoc($q);
        }
        function get_row($q){
            $result = mysql_query($q, $this->link);
            return mysql_fetch_assoc($result);
        }
        function count($q){
            $result = mysql_query($q, $this->link);
            $count = mysql_fetch_array($result);
            return $count[0];
        }
        function query($q){
            return mysql_query($q, $this->link);
        }
        function escape($str){
            return mysql_real_escape_string($str, $this->link);
        }
        function affected(){
            return mysql_affected_rows($this->link);
        }
        function insert($q){
            if(mysql_query($q, $this->link))
                return mysql_insert_id($this->link);
            return false;
        }
        function insert_array($table,$array){
            $q = "INSERT INTO `$table`";
            $q .=" (`".implode("`,`",array_keys($array))."`) ";
            $q .=" VALUES ('".implode("','",array_values($array))."') ";

            if(mysql_query($q, $this->link))
                return mysql_insert_id($this->link);
            return false;
        }
        function error(){
            $error = mysql_error($this->link);
            $errno = mysql_errno($this->link);
            return '['.$errno.'] '.$error;
        }
        function close(){
            $q = mysql_close($this->link);
            return $q;
        }
    }

}
?>

生成json函数

//将字段统一生成json
function echo_json($list){
    global $DB;
    class JSONObject{

    }

    $obj = new JSONObject();

    $obj->data = array();
    if($list){
        $obj->code = 200;
        $obj->msg = "获取成功";
        $i=0;
        while($res = $DB->fetch($list)){
        $obj->data[$i] = $res;
        $i++;
        }

    }
    else{
        $obj->code = 404;
        $obj->msg = "数据为空";

    }
    echo json_encode($obj);

}

使用方法：

$list = $DB->get_row("SELECT `id`,`upload_user`,`title`,`label`,`content`,`source` FROM `jokebox_list` WHERE `id`={$box_id} LIMIT 1;");
echo_json($list);