pdo 封装增删改查类

<?php

/**
 * Class model
 * @package Core\lib
 */
class model
{
    protected $pdo = null;      // 连接数据库
    protected $table = null;    // 表名
    protected $where = null;    // where 条件
    protected $order = null;    // order 条件
    protected $limit = null;    // limit
    protected $like = '';       // 包含 条件
    protected $field = '*';    // 要查询的 条件

    /**
     * model constructor.
     * @param $table
     * pdo连接数据库
     */
    public function __construct($table)
    {
        $database = conf::all('database');
        $this->table = $table;
        try{
            $this->pdo = new PDO($database['DSN'], $database['USERNAME'], $database['PASSWD']);
            $this->pdo->query('set names utf8');
        }catch(\PDOException $e){
            p($e->getMessage());
        }
    }



    /**
     * @return array
     *  查询所有
     */
    public function select()
    {
        $stmt = $this->pdo->prepare("select ".trim($this->field)." from ".$this->table." ".$this->where." ".$this->order." ".$this->limit."");

        $stmt->execute();

        $data = $stmt->fetchAll(PDO::FETCH_ASSOC);

        return $data;
    }


    /**
     * @return mixed
     *  单条查询
     */
    public function first()
    {
        $sql = "select ".$this->field." from ".$this->table." ".$this->where." limit 1";
        $res = $this->pdo->query($sql);
        $res->setFetchMode(PDO::FETCH_ASSOC); //数字索引方式
        $row = $res->fetch();
        return $row;
    }



    /**
     * @param $data
     * @return $this
     *  添加
     */
    public function insert($data)
    {
        if(is_array($data)){
            $val = array_values($data);
            $str = '';
            $key = array_keys($data);
            $keys = implode(',',$key);
            foreach($key as $k=>$v){
                $str.=":$v".',';
            }
            $str = rtrim($str,',');
            $stmt=$this->pdo->prepare("insert into ".$this->table."($keys) values($str)");
            $arr = [];
            foreach($key as $k=>$v){
                $arr[':'.$v] = $val[$k];
            }
            $stmt->execute($arr);
//            $this->pdo->lastInsertId();
            return $this;
        }
    }



    /**
     * @param $data
     * @return $this
     *  更新 修改
     */
    public function update($data)
    {
        $str = '';
        foreach($data as $k=>$v){
            $str.=$k.'='.':'.$k.',';
        }
        $str = rtrim($str,',');
        $stmt = $this->pdo->prepare("update ".$this->table." set ".$str." ".$this->where);
        $arr = [];
        foreach($data as $k=>$v){
            $arr[':'.$k] = $v;
        }
        if($stmt->execute($arr))
        {
            return $this;
//            echo "最后插入的ID:".$this->pdo->lastInsertId();
        }else{
            echo "执行失败";
        }
    }



    /**
     * @return $this
     * 删除
     */
    public function delete()
    {
        $sql="delete from ".$this->table." ".$this->where;
        $res = $this->pdo->exec($sql);
        return $res;
    }



    /**
     * @param $data
     * @return $this
     *  查询字段
     */
    public function field($field)
    {
        $this->field = is_array( $field ) ? '`' . implode( '`,`', $field ) . '`' : $field;
        return $this;
    }



    /**
     * @param $option
     * @return $this
     * where 条件
     */
    public function where($option)
    {
        $this->where = 'where ';
        $and = 'and';
        if(is_string($option)){
            $this->where.= $option;
        }elseif(is_array($option)){
            foreach($option as $k=>$v){
                $for = $k.'='.$v;
                $res = $this->where.= isset($mark) ? ' '.$and.' '.$for : $for;
                $mark = 1;
            }
        }
        return $this;
    }



    /**
     * @param $option
     * @return $this
     * 排序
     */
    public function order($option)
    {
        $this->order = 'order by ';
        if(is_string($option)){
            $this->order.= $option;
        }
        return $this;
    }



    /**
     * @param $page
     * @param null $pageSize
     * @return $this
     * 限制条数
     */
    public function limit($page,$pageSize = null)
    {
        if($pageSize == null){
            $this->limit = 'limit '.$page;
        }else{
            $pageval = intval($page-1) * $pageSize;
            $this->limit = "limit ".$page.",".$pageval ;
        }
        return $this;
    }



    /**
     * 字段和表名添加 `符号
     * 保证指令中使用关键字不出错 针对mysql
     * @param string $value
     * @return string
     */
    protected function _addChar($value)
    {
        if ('*'==$value || false!==strpos($value,'(') || false!==strpos($value,'.') || false!==strpos($value,'`')) {
            //如果包含* 或者 使用了sql方法 则不作处理
        } elseif (false === strpos($value,'`') ) {
            $value = '`'.trim($value).'`';
        }
        return $value;
    }



    /**
     * 过滤并格式化数据表字段
     * @param string $tbName 数据表名
     * @param array $data POST提交数据
     * @return array $newdata
     */
    protected function _dataFormat($tbName,$data)
    {
        if (!is_array($data)) return array();
        $table_column = $this->_tbFields($tbName);
        $ret=array();
        foreach ($data as $key=>$val) {
            if (!is_scalar($val)) continue; //值不是标量则跳过
            if (array_key_exists($key,$table_column)) {
                $key = $this->_addChar($key);
                if (is_int($val)) {
                    $val = intval($val);
                } elseif (is_float($val)) {
                    $val = floatval($val);
                } elseif (preg_match('/^\(\w*(\+|\-|\*|\/)?\w*\)$/i', $val)) {
                    // 支持在字段的值里面直接使用其它字段 ,例如 (score+1) (name) 必须包含括号
                    $val = $val;
                } elseif (is_string($val)) {
                    $val = '"'.addslashes($val).'"';
                }
                $ret[$key] = $val;
            }
        }
        return $ret;
    }



    /**
     * 取得数据表的字段信息
     * @param string $tbName 表名
     * @return array
     */
    protected function _tbFields($tbName)
    {
        $sql = 'SELECT COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE TABLE_NAME="'.$tbName.'" AND TABLE_SCHEMA="'.$this->_dbName.'"';
        $stmt = self::$_dbh->prepare($sql);
        $stmt->execute();
        $result = $stmt->fetchAll(PDO::FETCH_ASSOC);
        $ret = array();
        foreach ($result as $key=>$value) {
            $ret[$value['COLUMN_NAME']] = 1;
        }
        return $ret;
    }





}