本文操作环境:windows7系统、PHP7.4版、DELL G3电脑php中model的用法是什么?PHP模型Model类封装数据库操作示例php模型Model类封装数据库操作,结合实例形式分析了php使用Mysqli封装的针对数据库操作
本文操作环境:windows7系统、PHP7.4版、DELL G3电脑
php中model的用法是什么?
PHP模型Model类封装数据库操作示例
php模型Model类封装数据库操作,结合实例形式分析了php使用Mysqli封装的针对数据库操作相关实现与使用技巧:
具体如下:
<?php
//引入配置文件
include "./config.php";
class Model
{
public $link;//存储连接对象
public $tableName = "";//存储表名
public $field = "*";//存储字段
public $allFields = [];//存储当前表所有字段
public $where = "";//存储where条件
public $order = "";//存储order条件
public $limit = "";//存储limit条件
public function __construct($tableName)
{
//1.存储操作的表名
$this->tableName = PRE.$tableName;
//2.初始化连接数据库
$this->getConnect();
//3.获得当前表的所有字段
$this->getFields();
}
public function getConnect()
{
//1.连接数据库
$this->link = mysqli_connect(HOST,USER,PWD,DB,PORT);
//2.判断连接
if (mysqli_connect_errno($this->link)>0){
echo mysqli_connect_error($this->link);
exit;
}
}
public function query($sql)
{
$result = mysqli_query($this->link,$sql);
if ($result && mysqli_num_rows($result)>0) {
$arr = [];
while($row = mysqli_fetch_assoc($result)){
$arr[] = $row;
}
}
return $arr;
}
public function getFields()
{
//查看表结构
$sql = "desc {$this->tableName}";
//执行并发送SQL
$result = $this->query($sql);
$fields = [];
foreach ($result as $k => $v){
$fields[] = $v['Field'];
}
$this->allFields = $fields;
}
public function exec($sql)
{
$result = mysqli_query($this->link,$sql);
//处理结果集
if ($result && mysqli_affected_rows($this->link)>0){
//判断是否为添加操作,是则返回上一次执行的id
if (mysqli_insert_id($this->link)){
return mysqli_insert_id($this->link);
}
//删除修改操作成功则返回true
return true;
}else{
//未执行成功则返回false
return false;
}
}
public function select()
{
$sql = "select {$this->field} from {$this->tableName} {$this->where} {$this->order} {$this->limit}";
//执行并发送SQL
return $this->query($sql);
}
public function find($id="")
{
//判断id是否存在
if (empty($id)){
$where = $this->where;
}else{
$where = "where id={$id}";
}
$sql = "select {$this->field} from {$this->tableName} {$where} limit 1";
//执行并发送sql
$result = $this->query($sql);
//返回一条数据
return $result[0];
}
public function field($field)
{
//判断字段是否存在
if (empty($field)){
return $this;
}
$this->field = $field;
return $this;
}
public function count()
{
//准备SQL语句
$sql = "select count(*) as total from {$this->tableName} limit 1";
$result = $this->query($sql);
//返回总数
return $result[0]['total'];
}
public function add($data){
//判断是否是数组
if (!is_array($data)){
return $this;
}
//判断是否全是非法字段
if (empty($data)){
die("非法数据");
}
//过滤非法字段
foreach ($data as $k => $v){
if (!in_array($k,$this->allFields)){
unset($data[$k]);
}
}
//将数组中的键取出
$keys = array_keys($data);
//将数组中取出的键转为字符串拼接
$key = implode(",",$keys);
//将数组中的值转化为字符串拼接
$value = implode("','",$data);
//准备SQL语句
$sql = "insert into {$this->tableName} ({$key}) values('{$value}')";
//执行并发送SQL
return $this->exec($sql);
}
public function delete($id="")
{
//判断id是否存在
if (empty($id)){
$where = $this->where;
}else{
$where = "where id={$id}";
}
$sql = "delete from {$this->tableName} {$where}";
echo $sql;
//执行并发送
return $this->exec($sql);
}
public function update($data){
//判断是否是数组
if (!is_array($data)){
return $this;
}
//判断是否是全是非法字段
if(empty($data)){
die("非法数据");
}
$str = "";
//过滤非法字段
foreach ($data as $k => $v){
if ($k == "id"){
$where = "where id={$v}";
unset($data[$k]);
}
if (in_array($k,$this->allFields)){
$str .= "{$k}='{$v}',";
}else{
unset($data[$k]);
}
}
//判断是否有条件
if (empty($this->where)){
die("请输入条件");
}
//去掉最右侧的逗号
$str = rtrim($str,",");
$sql = "update {$this->tableName} set {$str} {$this->where}";
return $this->exec($sql);
}
public function where($where)
{
$this->where = "where ".$where;
return $this;
}
public function order($order)
{
$this->order = "order by ".$order;
return $this;
}
public function limit($limit)
{
$this->limit = "limit ".$limit;
return $this;
}
public function __destruct()
{
mysqli_close($this->link);
}
}
//自行调试
$a = new Model("表名");
// var_dump($a->find(3));
// var_dump($a->select());
// var_dump($a->count());
// $res = $a->select();
//var_dump($res);
?>
--结束END--
本文标题: php中model的用法是什么
本文链接: https://www.lsjlt.com/news/775.html(转载时请注明来源链接)
有问题或投稿请发送至: 邮箱/279061341@qq.com QQ/279061341
下载Word文档到电脑,方便收藏和打印~
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
2024-03-21
回答
回答
回答
回答
回答
回答
回答
回答
回答
回答
0