使用表达式Yii2选择字符串检测为列

我有这样一个问题:

use yii\db\Expression;

public function search($params)
{
$query = (new \yii\db\Query())
        ->select([
                "ir.id",
                "ir.no_surat",
                "tc.level",
                "nominal" => 'tc.cleaning',
                new Expression("clean as tagihan"),
                "tc.ditagihkan_bulan"
            ])

        ->from('ydepotras_estimator.repair_estimate as re')
        ->leftJoin(['ydepotras_estimator.inspection_report as ir'],
            "ir.id = re.inspection_id")
        ->innerJoin(['ydepotras_finance.tagihan_cleaning as tc'],
            " re.id = tc.repair_estimate_id");
}

new Expression("clean as tagihan"), 检测到Yii2 clean 作为列。但我需要塔吉汉列上的clean as值

+----+-------------+
| id |   tagihan   |
+----+-------------+
| 1  |   clean     |
| 2  |   clean     |
+----+-------------+

使现代化

$cleanigQuery = (new \yii\db\Query())
        ->select([
            "ir.id",
            "ir.no_surat",
            "tc.level",
            "nominal" => 'tc.cleaning',
            new Expression("clean as tagihan"),
            "tc.ditagihkan_bulan"
        ])
        ->from('ydepotras_estimator.repair_estimate as re')
        ->leftJoin(['ydepotras_estimator.inspection_report as ir'],
            "ir.id = re.inspection_id")
        ->innerJoin(['ydepotras_finance.tagihan_cleaning as tc'],
            " re.id = tc.repair_estimate_id");

$oneBarQuery = (new \yii\db\Query())
        ->select([
            "ir.id",
            "ir.no_surat",
            "tob.level",
            "nominal" => 'tob.one_bar',
                new Expression("one_bar as tagihan"),
            "tob.ditagihkan_bulan"
        ])
        ->from('ydepotras_estimator.repair_estimate as re')
        ->leftJoin(['ydepotras_estimator.inspection_report as ir'],
            "ir.id = re.inspection_id")
        ->innerJoin(['ydepotras_finance.tagihan_one_bar as tob'],
            " re.id = tob.repair_estimate_id");

所以,我可以这样做:

$cleanigQuery->union($oneBarQuery, true);

    $query = (new \yii\db\Query())
        ->select('*')
        ->from(['u' => $cleanigQuery])
        ->orderBy('no_surat');

    $dataProvider = new ActiveDataProvider([
        'query' => $query,

    ]);