php mysql 连贯操作

<?php
namespace app\index\controller;


use think\Db;

class User
{
    public function index()
    {
        // 一般的where方法进行字符串参数传入查询
//        dump(Db::name(&#39;user&#39;)
//            ->where(&#39;id=1 and name="wangjialin"&#39;)
//            ->find());

        // 参数为数组
        $map = [
//            &#39;id&#39;=> 2,
//            &#39;name&#39; => &#39;zhangsan&#39;,
//            &#39;age&#39; => [&#39;>&#39; , 10 ],
//            &#39;name&#39; => [&#39;like&#39; , &#39;%zhang%&#39;],
            &#39;age&#39; => [&#39;between&#39; , &#39;14,18&#39;]
        ];
//        dump(Db::name(&#39;user&#39;)->where($map)->select());

        // field order limit
//        dump(Db::name(&#39;user&#39;)
//            ->field(&#39;id , name  as username, age&#39;)
//            ->select());
//        dump(Db::name(&#39;user&#39;)
//            ->field([&#39;id&#39; , &#39;name as username&#39; , &#39;age&#39; , &#39;sex&#39;])
//            ->order(&#39;id desc&#39;)
//            ->limit(1)
//            ->select());

        // group having
//        dump(Db::name(&#39;user&#39;)
//            ->field([&#39;sum(age) as all_age&#39;])
//            ->group(&#39;password&#39;)
//            ->having(&#39;all_age > 50&#39;)
//            ->select());

        // 聚合操作count avg sum min max
        dump(Db::name(&#39;user&#39;)->count());
        dump(Db::name(&#39;user&#39;)->sum(&#39;age&#39;));
        dump(Db::name(&#39;user&#39;)->avg(&#39;age&#39;));

        // 获取最近的执行的sql语句
        dump(Db::name(&#39;user&#39;)->getLastSql());
    }


}