mysqli连接数据库实现链式增删改查类_mysqli连接数据库 更改字段值

 简单的用mysqli连接数据库实现的链式增删改查的类，大家可以自行扩展多表查询方法，关联查询方法等。对于用惯了thinkphp的同学来说，这个轻量级的类对于开发微型应用应该对您有所帮助。

<?php
define("HOST","host");
define("USER", "user");
define("PASSWORD", "pwd");
define("DBNAME", "dbname");
class Model{
  public $field = '*';
  public $tabname;
  public $where;
  public $order;
  public $limit;
  private $connect;
  //构造函数，链接数据库，给表赋值
  public function __construct($tabname){
    $this->connect = mysqli_connect(HOST,USER,PASSWORD,DBNAME);
    if (!$this->connect) die("连接错误: " . mysqli_connect_error());
    $this->tabname=$tabname;
  }
  //组合字段
  public function field($field){
    $this->field=$field;
    return $this;
  }
  //组合where条件
  public function where($where){
    $this->where="where ".$where;
    return $this;
  }
  //组合order排序条件
  public function order($order){
    $this->order="order by ".$order;
    return $this;
  }
  //组合limit限制条数
  public function limit($limit){
    $this->limit="limit ".$limit;
    return $this;
  }
  //组合和执行select语句
  public function select(){
    $sql="select {$this->field} from {$this->tabname} {$this->where} {$this->order} {$this->limit}";
    $rst=mysqli_query($this->connect,$sql);
    if(!$rst) $this->error();
    while ($row=mysqli_fetch_assoc($rst)) {
      $rows[]=$row;
    }
    return $rows;
  }
  
  //组合和执行insert语句单条插入
  public function insert($post){ //数据库插入操作,接收数组
    foreach ($post as $key => $value) {
      $keys[]=$key;
      $vals[]="'".$value."'";
    }
    $keyStr=join(",",$keys);
    $valStr=join(",",$vals);
    $sql="insert into {$this->tabname} ($keyStr) values ($valStr)";
    $rst = mysqli_query($this->connect,$sql);
    if ($rst) {
      return mysqli_insert_id($this->connect);
    }else{
      $this->error();
    }
  }
  
  
  //组合和执行insert语句多条插入
  /*
  $post['keys'] = ['id','name','old']
  $post['values'] = [
    [1,'张三','29'],
    [2,'李四','39']
  ]
  */
  public function inserts($post){ //数据库插入操作,接收二维数组
    $keyStr = join(",",$post['keys']);
    $valStr = '';
    foreach ($post['values'] as $value) {
        $vals = [];
        foreach ($value as $v){
            $vals[] = "'".$v."'";
        }
        $valStr .= '('.join(',',$vals).'),';
    }
    $valStr = trim($valStr,',');
    $sql="insert into {$this->tabname} ($keyStr) values $valStr";
    $rst = mysqli_query($this->connect,$sql);
    if ($rst) {
      return mysqli_affected_rows($this->connect);
    }else{
      $this->error();
    }
  }
  //删除数据
  public function delete(){
    if(!$this->where) die('删除数据必须指定删除条件，否则会删除数据库所有数据，请谨慎！');
    $sql="delete from {$this->tabname} {$this->where}";
    $rst = mysqli_query($this->connect,$sql);
    if ($rst) {
      return mysqli_affected_rows($this->connect);
    }else{
      $this->error();
    }
  }
  //组合和执行updata语句
  public function update($post){
    foreach ($post as $key => $value) {
      $sets[]="{$key}='{$value}'";
    }
    $setStr=join(",",$sets);
    $sql="update {$this->tabname} set {$setStr} {$this->where} ";
    $rst = mysqli_query($this->connect,$sql);
    if ($rst) {
      return mysqli_affected_rows($this->connect);
    }else{
      $this->error();
    }
  }
  //从表中取一行数据
  public function find(){ 
    $sql="select {$this->field} from {$this->tabname} {$this->where} limit 1";
    $rst=mysqli_query($this->connect,$sql);
    if(!$rst) $this->error();
    while ($row=mysqli_fetch_assoc($rst)) {
      $rows=$row;
    }
    return $rows;
  }
  
  //错误信息
  private function error(){
      die(mysqli_error($this->connect));
  }
  
  //获取总行数
  public function total(){ 
    $sql="select count(*) from {$this->tabname}";
    $rst=mysqli_query($this->connect,$sql);
    if ($rst) {
      $row=mysqli_fetch_row($rst);
      return $row[0];
    }else{
      $this->error();
    }
  }
}
//Model类对象工厂
function M($tabname){
  return new Model($tabname);
}

使用方法

<?php
include 'M.class.php';
$data = [
    'follow_group_id'   =>  1,
    'follow_id'         =>  10,
    'fid'               =>  20,
    'uid'               =>  30
];
$datas = [
    'keys'  =>  ['follow_group_id','follow_id','fid','uid'],
    'values'=>  [
        ['1',3,4,5],
        [6,7,8,9]
    ]
];
//插入单条数据
$insert = M('数据表名')->insert($data);
//插入多条
$inserts= M('数据表名')->inserts($datas);
//查询多条数据
$datas = M('数据表名')->field('id,name,old')->where('id>10')->order('id desc')->limit('0,50')->select();
//查询单条数据
$data = M('数据表名')->field('id,name,old')->where('id>10')->order('id desc')->limit('0,50')->find();
//删除数据
$del = M('数据表名')->where('id=10')->delete();
//修改数据
$update = M('数据表名')->where('id=10')->update($data);