<?php

namespace app\controllers;

use YII;

use yii\db\Query;

use yii\web\Controller;

class TestController extends Controller

{

    public function actionTest()

    {

        //YII2的Query的使用

        //Query与createCommand的区别是createCommand是直接写一个SQL来执行。

        //Query是根据参数和数据库类型生成不同的SQL，提升数据库可迁移性。

        //通过all查询多条记录

        //我这里用tb_user表来进行演示

        $data1 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->all();

        //指定where条件查询

        $data2 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where('id=:id', [':id' => '2'])

            ->all();

        //通过one查询单条记录

        $data3 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where('id=3')

            ->one();

        //判断记录是否存在

        $exists = (new Query())->from('{{%user}}')

            ->where('name="aaa"')

            ->exists();

        if ($exists) {

            echo 'name=aaa 存在';

        }

        //定义字段别名

        //注意真实的字段名写后面，别名写前面

        $data4 = (new Query())->select(['ids' => 'id', 'names' => 'name'])

            ->from('{{%user}}')

            ->where('1=1')

            ->all();

        //通过orderby排序，和limit限制条数

        $data5 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where('1=1')

            ->orderBy('id desc')

            ->limit(3)

            ->all();

        //多个and条件

        //参数是数组，一个key对应一个value，默认以and拼接

        $data6 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['id' => 3, 'name' => 'aaa'])

            ->one();

        //in条件

        $data7 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['id' => [4, 5, 6]])

            ->all();

        //或者如下方式

        $data7_2 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['in', 'id', [4, 5, 6]])

            ->all();

        //count统计

        $count = (new Query())->from('{{%user}}')->count();

        echo '总记录数: ', $count;

        //大于，大于等于，小于，小于等于where条件

        $data8 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['>=', 'id', 5])

            ->all();

        $data9 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['<=', 'id', 3])

            ->all();

        //like查询

        $data10 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['like', 'name', 'dd'])

            ->all();

        //between筛选和group by分组

        //查找出age在18到24之间的，并按sex分组

        $data11 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['between', 'age', 18, 24])

            ->groupBy('sex')

            ->all();

        //having筛选

        //按sex分组，然后统计人数大于3的

        $data12 = (new Query())->select(['sex', 'cnt' => 'count(*)'])

            ->from('{{%user}}')

            ->groupBy('sex')

            ->having('cnt > 3')

            ->all();

        //or逻辑条件

        //查找姓名为aaa或bbb的用户

        //之前where数组是以key=>value方式传递的，如果要表达复杂逻辑关系，

        //数组第一个元素必须声明是什么逻辑，and还是or

        //第二个元素表示逻辑左边

        //第三个元素表示逻辑右边

        $data13 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['or', ['name' => 'aaa'], ['name' => 'bbb']])

            ->all();

        //复杂的where条件

        //我这里只是作为演示

        //SELECT `id`, `name` FROM `tb_user` WHERE ((`name`='aaa') OR (`name`='bbb')) OR ((`name`='ccc') OR (`name`='ddd'))

        $data14 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where([

                'or',

                [

                    'or',

                    ['name' => 'aaa'],

                    ['name' => 'bbb'],

                ],

                [

                    'or',

                    ['name' => 'ccc'],

                    ['name' => 'ddd'],

                ],

            ])

            ->all();

        //and和or嵌套where条件

        //SELECT `id`, `name` FROM `tb_user` WHERE (`sex`=1) AND ((`name` LIKE '%aa%') OR (`name` LIKE '%bb%'))

        $data15 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where([

                'and',

                ['sex' => 1],

                [

                    'or',

                    ['like', 'name', 'aa'],

                    ['like', 'name', 'bb'],

                ],

            ])

            ->all();

        //有些时候我们需要根据用户传递过来的参数追加where条件

        //追加and条件

        $query = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where('sex=1');

        //追加age大于18的条件

        $query->andWhere(['>', 'age', 18]);

        echo $query->createCommand()->getRawSql();

        //追加or条件

        $query2 = (new Query())->select(['id', 'name'])

            ->from('{{%user}}')

            ->where(['like', 'name', 'aa']);

        //追加name相似bb的条件

        $query2->orWhere(['like', 'name', 'bb']);

        echo $query2->createCommand()->getRawSql();

        //表别名和连接查询

        //SELECT `u`.`id`, `u`.`name`, `aa`.`item_name` FROM `tb_user` `u` LEFT JOIN `tb_auth_assignment` `aa` ON aa.user_id = u.id

        $data16 = (new Query())->select(['u.id', 'u.name', 'aa.item_name'])

            ->from(['u' => '{{%user}}'])

            ->leftJoin(['aa' => '{{%auth_assignment}}'], 'aa.user_id = u.id')

            ->all();

    }

}