主要功能：车辆名称搜索！！！主表：car（外键主要有shop_car_id）关联表分别有shop_car（car表进一步分类，外键：brand_id,type_id)，car_brand（车辆的***表），car_brand_type（***的类型表 外键car_brand_id 车辆的类型）
此处需要接受一个参数 : $carName = input("searchValue");
1.联表将查询结果生成sql语句
$car = Db::name("car")
->alias("car")
->join("shop_car t", "car.shop_car_id=t.id")
->field("car.id car_number_id,t.price,t.desc,car.lat,car.lng,t.brand_id,t.type_id")
->buildSql();
汇总：select(false); fetchsql(true)->select();生成不带括号的sql语句, 需要另加括号 $list = Db::table("(" . $car . ")as cars")
buildSql 生成带括号的sql语句 $list = Db::table("$car as cars")
第一步的运行结果："( SELECT car.id car_number_id,`t`.`price`,`t`.`desc`,`car`.`lat`,`car`.`lng`,`t`.`brand_id`,`t`.`type_id` FROM `yisu_car_number` `car` INNER JOIN `yisu_shop_car` `t` ON `car`.`shop_car_id`=`t`.`id` )"
方法1：子查询+联表：
2.将子查询结果作新表cars继续联表查询
$list = Db::table($car . "cars")
->join("car_brand brand", "cars.brand_id=brand.id", "LEFT")
->join("car_brand_type types", "cars.type_id=types.id", "LEFT")
->field("cars.*,brand.*,types.*,brand.name brand_name,types.name types_name")
->page($this->page, 5)
->whereOr("types.name", "like", "%" . $carName . "%")
->whereOr("brand.name", "like", "%" . $carName . "%")
->select();
方法2：子查询+闭包
$list = Db::table($car . "cars")
->whereOr('brand_id', 'IN', function ($query)use($carName) {
$query->name('car_brand')->where("name","like","%".$carName."%")->field("id");
})
->whereOr('type_id', 'IN', function ($query)use($carName) {
$query->name('car_brand_type')->where("name","like","%".$carName."%")->field("id");
})
->page($this->page, 5)
->select();
3.下面只需进行foreach遍历，数据重组
$arr=[];//过滤不需要的数据
foreach ($list as $k => $v) {
$arr[$k]["title"] = $v["brand_name"].$v["types_name"];
}
return $arr;
运行结果：
[
{
"title": "奥***迪Q5",
"price": "22.00",
"hotNum": 7,
"distance": "6525.4km"
},
{
"title": "奥***迪Q5",
"price": "33.00",
"hotNum": 4,
"distance": "6948.67km"
},
{
"title": "奥***迪A6",
"price": "89.00",
"hotNum": 1,
"distance": "0m"
},
{
"title": "奥***迪A6",
"price": "66.00",
"hotNum": 0,
"distance": "5726.73km"
},
{
"title": "奥***迪A6",
"price": "90.00",
"hotNum": 2,
"distance": "5726.73km"
}
]
备注：数据数据库自己添加的，跟实际车辆型号不一样请谅解！！！
