thinkphp 数据访问

Posted 2020-08-24 奔跑的葛根

<?php
namespace Admin\\Controller;
use Think\\Controller;
class MainController extends Controller
{
    public function showList()
    {
        echo "大苹果商城";
    }
    
    public function test()
    {
        //数据访问
        //造模型对象
        $nation = D("Nation");
        
        //查询
        //$a = $nation->select(); //查所有，返回关联数组
        //$a = $nation->select("n001,n002,n003"); //通过主键查
        //$a = $nation->find("n002"); //查一条数据
        
        连贯操作
        $a = $nation->where("name=\'汉族\' or name=\'回族\'")->select(); //加条件
        $a = $nation->table("Info")->select(); //切换表
        $a = $nation->field("name")->select(); //查询指定字段


        $a = $nation->order("code desc")->select(); //排序
        $a = $nation->limit(3,3)->select(); //分页
        $a = $nation->page(3,3)->select(); //分页
        $a = $nation->table("Car")->field("Brand,avg(Price)")->group("Brand")->select(); //分组
        $a = $nation->table("Car")->field("Brand,avg(Price)")->group("Brand")->having("avg(Price)>50")->select();
        
        $a = $nation->alias(\'a\')->field("b.Code as \'code\',b.Name as \'name\',a.name as \'民族\'")->join("Info b on a.Code=b.Nation")->select();
        
        $a = $nation->table("car")->distinct(true)->field("brand")->select();
        
        $a = $nation->where("code=\'n003\'")->getField("name"); //获取某一列的值
        
        $a = $nation->table("car")->sum(Price);
        var_dump($a);
        
        //$sql = "update nation set name=\'矮人族\' where code=\'n001\'";
        //$a = $nation->query($sql); //执行查询
        //$a = $nation->execute($sql); //执行其他操作
        //var_dump($a);
        
        
        
    }
}