在 Yii 2 下，[[yii\validators\UniqueValidator|unique(唯一性)]]，组合字段的唯一性，在公共的模型逻辑层中自定义错误信息

    /**
     * {@inheritdoc}
     */
    public function rules()
    {
        return [
            [['group_id', 'code', 'name'], 'required'],
            [['status', 'created_at', 'updated_at'], 'integer'],
            [['group_id', 'code', 'name'], 'string', 'max' => 32],
            [['group_id', 'code'], 'unique', 'targetAttribute' => ['group_id', 'code']],
            [['group_id', 'name'], 'unique', 'targetAttribute' => ['group_id', 'name']],
        ];
    }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        $rules = [
        ];
        $parentRules = parent::rules();

        return ArrayHelper::merge($rules, $parentRules);
    }

{
    "code": 20004,
    "message": "Data validation failed: The combination \"015ce30b116ce86058fa6ab4fea4ac63\"-\"wxcq\" of Group ID and Code has already been taken."
}

{
    "code": 20004,
    "message": "数据验证失败：The combination \"015ce30b116ce86058fa6ab4fea4ac63\"-\"wxcq\" of 租户ID and 栏目代码 has already been taken."
}

        if (is_array($this->targetAttribute) && count($this->targetAttribute) > 1) {
            // fallback for deprecated `comboNotUnique` property - use it as message if is set
            if ($this->comboNotUnique === null) {
                $this->message = Yii::t('yii', 'The combination {values} of {attributes} has already been taken.');
            } else {
                $this->message = $this->comboNotUnique;
            }
        } else {
            $this->message = Yii::t('yii', '{attribute} "{value}" has already been taken.');
        }

    /**
     * @inheritdoc
     */
    public function rules()
    {
        $rules = [
            [['group_id', 'code'], 'unique', 'targetAttribute' => ['group_id', 'code'], 'message' => Yii::t('app', 'The combination {values} of {attributes} has already been taken.')],
            [['group_id', 'name'], 'unique', 'targetAttribute' => ['group_id', 'name'], 'message' => Yii::t('app', 'The combination {values} of {attributes} has already been taken.')],
        ];
        $parentRules = parent::rules();

        unset($parentRules[3], $parentRules[4]);

        return ArrayHelper::merge($rules, $parentRules);
    }

<pre class="wp-block-syntaxhighlighter-code">

<?php
return [
    'The combination {values} of {attributes} has already been taken.' => '组合{attributes}的值"{values}"已经被占用了。',
];


</pre>

<pre class="wp-block-syntaxhighlighter-code">

<?php
return [
    'The combination {values} of {attributes} has already been taken.' => '组合{attributes}的值"{values}"已经被占用了。',
];


</pre>

{
    "code": 20004,
    "message": "Data validation failed: The combination \"015ce30b116ce86058fa6ab4fea4ac63\"-\"wxcq\" of Group ID and Code has already been taken."
}

{
    "code": 20004,
    "message": "数据验证失败：组合租户ID and 栏目代码的值\"\"015ce30b116ce86058fa6ab4fea4ac63\"-\"wxcq\"\"已经被占用了。"
}