博客列表 >08-02作业:实现一个基本的数据库操作类(CURD)

08-02作业:实现一个基本的数据库操作类(CURD)

子傅
子傅原创
2019年08月04日 23:44:20738浏览

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测试页代码 test.php:

实例

<?php
/**
 * Created by PhpStorm.
 * User: A
 * Date: 2019-08-03
 * Time: 03:24
 */
include "./Db.php";
$db=new Db();
//功能测试
//1、增   新增一条数据   待插入的单条新数据  $data_1 = array("name.=.破军","sex.=.0","age.=.88","salary.=.7770");

echo "<br>";
$data_1 = array("name.=.破军","sex.=.0","age.=.88","salary.=.7770");
$res=$db->table("staff")->insert($data_1);
echo var_dump($res);
if($res){echo "新增单条数据成功";}else{echo"新增单条数据失败";};

//*************************************************************************************

//2、增 新增多条数据 多条新数据  $data_2 = array(array("name.=.风行者","age.=.38","salary.=.7800"), array("name.=.夜语","age.=.32","salary.=.7900"));

echo "<br>";
$data_2 = array(array("name.=.风行者","age.=.38","salary.=.7800"), array("name.=.夜语","age.=.32","salary.=.7900"));
$res= $db->table("staff")->insert($data_2);
echo var_dump($res);
if($res){echo "新增多条数据成功";}else{echo"新增多条数据失败";};

//************************************************************************************

//3、删除 删除一条记录  $where_1 = array("id.=.203");
echo "<br>";
$where_1 = array("id.=.203");
$res= $db->table("staff")->where($where_1)->delete();
if($res){echo "删除一条数据成功";}else{echo"删除一条数据失败";};

//************************************************************************************

//4、改 更新一条记录  $where_2 = array("salary.=.7900");   更新为 :$data_1 =array("salary.=.9123");
echo "<br>";
$where_2 = array("salary.=.7900");
$data_1 =array("salary.=.9123");
$res= $db->table("staff")->where($where_2)->update($data_1);
if($res){echo "更新数据成功";}else{echo"更新数据失败";};

//************************************************************************************

//5、无条件查询   table("表名")  field("显示字段列表")  select()  Db类中的查询方法
echo "<br>";
$res = $db->table("staff")->field("name,age,sex")->select();
foreach ($res as $val){
    echo "<pre>";
    print_r($val);
}

//************************************************************************************

//5、复合条件查询  条件 $where_4 = array("age.>.20","name.LIKE.%武%");

echo "<br>";
$where_4 = array("age.>.20","name.LIKE.%武%");
$res = $db->table("staff")->field("name,age,sex,salary")->where($where_4)->select();
foreach ($res as $val){
    echo "<pre>";
    print_r($val);
}

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Db类的定义代码

实例

<?php
/**
 * Created by PhpStorm.
 * User: A
 * Date: 2019-08-03
 * Time: 01:24
 */
/* table()-> |field()->insert(array $data)    增 测试完成
          -> |where(array $where_data)->delete();   删 测试完成
          -> |where(array $where)->update(array $data) 改 测试完成
          -> |field()->where(array $where_data)->select() 查 测试完成

   table(  参数类型 str  )  样例: table('user')  数据库语句中显示为: `user`
   field(  参数类型 str  )  样例: field("name,sex,age,salary") 数据库语句中显示为:`name`,`sex`,`age`,`salary`
   insert( 参数类型 array)  样例: insert( array("name.=.武破天","sex.=.0") )
   where(  参数类型 array)  样例: where( array("age.>.25","name.link.武%","salary.in.(3000,8000)") );
   array $data  属性数据样式: array("'小龙女',1,32,8000") 或 array("name.=.风尊者","age.=.29","salary.=.9000")
   array $where 条件数据样式: array("`age`= 25","`name`= '武松'") 或 array("salary in (3000,9000)","`name` like '武%'")
*/
class Db{
    private $sql = '';
    private $table_name = '';
    private $field = '*';
    private $where = [];
    private $where_or = [];
    private $where_data =[];
    private $where_data_or=[];
    private $bind_data = [];
    private $bind_values = [];
    private $group = '';
    private $having ='';
    private $order = '';
    private $limit = '';
    //数据库连接 --构造函数
    public function __construct()
    {
        require "./config.php";
        try{
            $this->pdo=new PDO($dns,$username,$password);
            echo '数据库连接OK';
        }catch(PDOException $e){

            die('数据库连接失败'.$e->getMessage());
        }
        return $this;
    }

    //参数初始化重置
    public function var_clear(){
        $this->sql = '';
        $this->table_name = '';
        $this->field = '*';
        $this->where = [];
        $this->where_or = [];
        $this->where_data =[];
        $this->where_data_or =[];
        $this->bind_data = [];
        $this->bind_values =[];
        $this->group = '';
        $this->having ='';
        $this->order = '';
        $this->limit = '';
    }
    //数据库查询字段参数赋值获取 table('str参数')---------------------------------
    public function table($table)
    {
        $this->table_name='`'.$table.'`';
        return $this;
    }
    //指定查询字段 field('str参数')
    public function field($field)
    {
        if($field=='*'){
            $this->field = $field;
        }else{
            $fields= explode (',',$field);
            $field_str='';
            foreach($fields as $var)
            {
                $field_str .= '`'.$var.'`,';
            }
            $fields = rtrim($field_str,',');
            $this->field = $fields;
        }
        return $this;
    }
    //指定查询条件 array("age.>.25","name.=.武松")
    public function where(array $where)
    {
        $this->where = $where;
        return $this;
    }
    //or条件查询
    public function where_or(array $where)
    {
        $this->where_or = $where;
        return $this;
    }
    //分组-简单字段分组
    public function group($field)
    {
        $this->group = '`'.$field.'`';
        return $this;
    }
    //分组-条件分组
    public function having($having)
    {
        $this->having = $having;
        return $this;
    }
    // 指定排序
    public function order($order)
    {
        $this->order = $order;
        return $this;
    }
    // 指定查询数量显示
    public function limit($limit)
    {
        $this->limit = $limit;
        return $this;
    }
    //数据库查询条件字段参数赋值获取 结束 ---------------------------------

    // 一.自定义常用方法
    //查询1条数据,多用于登录验证
    public function item(){
        $this->limit(1);
        $this->_build_sql('select');
        $stmt = $this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        $stmt->execute();
        $item = $stmt->fetchAll(PDO::FETCH_ASSOC);
        return $item ? $item[0] : false;
    }


    // 二 : 常规数据操作
    //1.新增操作-------------------------------------------------------------
    public function insert(array $data)
    {
        $this->_build_sql('insert',$data);
        $stmt=$this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        if(count($data)==count($data,1)){
            if($stmt->execute())
            {
                $this->var_clear();
                return true;
            }else{
                return false;
            }
        }else{
            //绑定的属性名 : :varName
            $data =$this->bind_data;
            $values = $this->bind_values;
            foreach ($data as $k => $var)
            {
                foreach($values as $val)
                {
                    $tag = ltrim($val,':');
                    // $val = :属性名   $data[$k][$tag] 对应的属性值
                    $stmt->bindValue($val, $data[$k][$tag]);
                }
                if(!$stmt->execute()){  return false;  }
            }
            $this->var_clear();
            return true;
        }
    }

    //2.删除操作 -------------------------------------------------------------
    public function delete()
    {
        $this->_build_sql('delete');
        $stmt=$this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        if($stmt->execute())
        {
            //echo '删除数据成功';
            $this->var_clear();
            return true;
        }else{
            return false;
        }
    }

    //3.更新操作-------------------------------------------------------------------
    public function update($data)
    {
        $this->_build_sql('update',$data);
        $stmt=$this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        if($stmt->execute())
        {
            $this->var_clear();
            return true;
        }else{
            return false;
        }
    }

    //4.查询操作-------------------------------------------------------------------
    public function select()
    {
        $this->_build_sql('select');

        $stmt=$this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        $stmt->execute();
//        if($stmt->execute())
//        {
//            echo '查询数据成功';
//        }else{
//            echo '查询数据失败';
//        }
        $res=$stmt->fetchAll(PDO::FETCH_ASSOC);
        $this->var_clear();
//        echo '<pre>';
//        print_r($res);
        return $res;
    }

    //5.统计总数-------------------------------------------------------------------
    public function count_rows()
    {
        $this->_build_sql('count');
        $stmt=$this->pdo->prepare($this->sql);
        $this->_build_bind_value($stmt);
        if($stmt->execute()){
            $this->var_clear();
        }
        else{
            echo "数据统计失败7";
        }
        $res = $stmt->fetchColumn(0);
        return $res;

    }

    // 二 : 构造sql的语句生成
    public function _build_sql($type,array $data=[])
    {
        switch ($type){

            case 'insert':
                $this->_build_sql_insert($data);
                break;

            case 'delete':
                $this->_build_sql_delete();
                break;

            case 'update':
                $this->_build_sql_update($data);
                break;

            case 'select':
                $this->_build_sql_select();
                break;

            case 'count':
                $this->_build_sql_count();
                break;
        }
    }

    //1.增:构造sql_insert生成 数据格式
    // array("name.=.破军","sex.=.0","age.=.88","salary.=.7770")
    public function _build_sql_insert(array $data)
    {
        //新增语句: INSERT INTO table_name ( column1,column2) VALUES (val1,val2),(val1,val2)
        $insert_fields='';
        $insert_values='';
        $insert_data=[];
        $insert_i_fields='';
        $insert_i_values='';

        if(count($data,0)==count($data,1))
        { //1条记录新增处理方式 一维数组数据
            foreach ($data as $var)
            {
                $a = strpos($var,'.=');
                $b = strrpos($var,'=.');
                $insert_field = substr($var,0,$a);
                $insert_var = substr($var,$b+2);
                $insert_data["$insert_field"]=$insert_var;
                $insert_fields .= ' `'.$insert_field.'`,';
                $insert_values .=':'.$insert_field.',';
            }
            $this->bind_data = $insert_data;

            $insert_fields=rtrim($insert_fields,',');
            $this->field ='('.$insert_fields.')';

            $insert_values = rtrim($insert_values,',');
            $sql ="INSERT INTO {$this->table_name} {$this->field} VALUES ";
            $sql .='('.$insert_values.')';
            return $this->sql=$sql;

        }else{
            //多条记录新增方式,二维数组数据
            //array(array("name.=.风行者","age.=.38","salary.=.7800"), array("name.=.夜语","age.=.32","salary.=.7900"));
            for($i=0;$i<count($data,0);$i++)
            {
                foreach($data[$i] as $var)
                {
                    $a = strpos($var,'.=');
                    $b = strrpos($var,'=.');
                    $insert_i_field = substr($var,0,$a);
                    $insert_i_value = substr($var,$b+2);

                    $insert_data[$i]["$insert_i_field"]=$insert_i_value;

                    if(!strstr($insert_i_fields,$insert_i_field)){
                        $insert_i_fields .= ' `'.$insert_i_field.'`,';
                    }

                    if(!strstr($insert_i_values,$insert_i_field)){
                        $insert_i_values .=':'.$insert_i_field.',';
                    }

                }
                $insert_fields=rtrim($insert_i_fields,',');
                $insert_i_values = rtrim($insert_i_values,',');
            }
            $this->bind_data=$insert_data;
            $this->bind_values=explode(',',$insert_i_values);
            $this->field ='('.$insert_fields.')';
            $insert_values ='('.$insert_i_values.'),';
            $insert_values = rtrim($insert_values,',');
            $sql ="INSERT INTO {$this->table_name} {$this->field} VALUES  $insert_values";
            return $this->sql=$sql;
        }
    }


    //2.删:构造sql_delete生成
    public function _build_sql_delete()
    {
        //删除语句: DELETE FROM table_name WHERE ???
        $sql = "DELETE FROM {$this->table_name} ";
        $sql .= $this->_build_sql_where();
        return $this->sql=$sql;
    }

    //3.改:构造sql_update生成  数据格式
    //条件格式  $where = array("age.>.25","name.link.武%","salary.in.(3000,8000)");
    //数据格式 $data = $data_4 =array("salary.=.9800");
    public function _build_sql_update(array $data)
    {
        //更新语句: UPDATE语句模板 UPDATE table_name set column1=value1,column1=value1 WHERE ?
        $sql = "UPDATE {$this->table_name} SET ";
        $update_str='';
        $update_data =[];
        foreach ($data as $var)
        {
            $a = strpos($var,'.=');
            $b = strrpos($var,'=.');
            $update_field = substr($var,0,$a);
            $update_var = substr($var,$b+2);
            $update_data["$update_field"]=$update_var;
            $update_str .= ' `'.$update_field.'` = :'.$update_field.' ,';
        }
        $update_str = rtrim($update_str,' ,');
        $this->bind_data = $update_data;
        $sql .= $update_str;
        $sql .= $this->_build_sql_where();
        return $this->sql=$sql;
    }



    //4.查:构造sql_select生成  limit属于最后一个参数
    public function _build_sql_select()
    {
        //查询数据SELECT语句模板 SELECT 字段列表 FROM table1,table2 [WHERE ] [GROUP BY] [ORDER BY] [LIMIT]
        $sql="SELECT {$this->field} FROM {$this->table_name}";

        if ($this->where){ $sql .= $this->_build_sql_where(); }

        if ($this->where_or){ $sql .= $this->_build_sql_where_or(); }

        if($this->group){  $sql .=" group by {$this->group}"; }

        if($this->having){ $sql .=" having {$this->having}"; }

        if ($this->order){ $sql .= " order by {$this->order}";}

        if($this->limit){  $sql .= " limit {$this->limit}";}

        return $this->sql=$sql;
    }

    //5.统计sql_count
    public function _build_sql_count()
    {
        $where = $this->_build_sql_where();
        $this->sql ="SELECT count({$this->field}) FROM {$this->table_name}{$where}";
        return $this->sql;
    }

    //8.构造sql_where  and 语句 生成
    //数据的类型:array("age.>.25","name.=.武松","salary.in.(3000,8000),","sex.is.null","age.like.龙%");
    public function _build_sql_where()
    {
        $where_data=[];
        $where='';
        $sql_where='';

        if(empty($this->where)){
            $sql_where='';
        }else{
            foreach ($this->where as $var)
            {
                $a = strpos($var,'.');
                $b = strrpos($var,'.');
                $c=$b-$a-1;
                $where_field = substr($var,0,$a);
                $where_tag = substr($var,$a+1,$c);
                $where_var = substr($var,$b+1);
                $where_data["w_$where_field"]=$where_var;
                $where .= ' AND `'.$where_field.'` '.$where_tag.' :w_'.$where_field;
            }
            $this->where_data = $where_data;
//            echo '<pre>';
//            print_r($this->where_data);
//            echo '--data<br>';
            $where = ltrim($where," AND");
            $sql_where .=" WHERE ".$where;
        }
//        echo $sql_where.'<br>';
        return $sql_where;
    }

    //9.构造sql_where  or 语句 生成
    public function _build_sql_where_or()
    {
        $where_data_or = [];
        $where_or='';
        if(empty($this->where_or)){
            $where_or='';
        }else{
            foreach ($this->where_or as $var)
            {
                $a = strpos($var,'.');
                $b = strrpos($var,'.');
                $c=$b-$a-1;
                $where_field = substr($var,0,$a);
                $where_tag = substr($var,$a+1,$c);
                $where_var = substr($var,$b+1);
                $where_data_or["r_$where_field"]=$where_var;
                $where_or .= ' or `'.$where_field.'` '.$where_tag.' :r_'.$where_field;
            }
            $this->where_data_or = $where_data_or;
        }
        return $where_or;
    }


    //10.参数绑定,常见参数 where条件数组   where_or条件数组  update 更新数组  insert 新增数组
    private  function _build_bind_value($stmt)
    {
        if($this->where_data)
        {
            $where_data = $this->where_data;
            foreach($where_data as $key=>$var)
            {
//                  echo $key.'<br>';
//                  echo $var.'<br>';
                $stmt->bindValue(':'.$key,$var);
            }
        }

        if ($this->bind_data)
        {
             $data =$this->bind_data;
            //判断数组是否为多维数组 多为数组数据处理在155行处理
            if(count($data,0)==count($data,1)){
                foreach($data as $k=>$v)
                {
//                   echo $k.'--';
//                   echo $v.'<br>';
                    $stmt->bindValue(':'.$k,$v);
                }
            }
        }

        if($this->where_data_or)
        {
            $where_data_or = $this->where_data_or;
            foreach($where_data_or as $key=>$var)
            {
                $stmt->bindValue(":".$key,$var);
            }

        }
    }
}

运行实例 »

点击 "运行实例" 按钮查看在线实例

配置文件 confing.php

实例

<?php
/**
 * Created by PhpStorm.
 * User: A
 * Date: 2019-08-03
 * Time: 01:20
 * 说明 数据库连接参数
 */

$dns="mysql:host=127.0.0.1;dbname=php";
$username='root';
$password='root';

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