我可以使用以下代码对gridview中的列求和：
<?php
$command = Yii::$app->db->createCommand("SELECT sum(net_total) FROM estimate");
$sum = $command->queryScalar();
echo 'Total ='. $sum;
?>
我在DB中有一个列为discharge_date（它是日期和时间字段），我想更改该列上过滤器的总和。也就是说，如果过滤后的数据显示了五条记录，那么我只想要这五条记录的总和。谢谢
根据答案更新
代码如下：
$query = app'models'Estimate::find();
$dataProvider = new ActiveDataProvider([
'query' => $query,
]);
$ids = [];
foreach($dataProvider as $i => $model) {
$ids[] = $model->id;}
$command = Yii::$app->db->createCommand("SELECT sum(net_total) FROM estimate WHERE `id` IN ('.implode(',',$ids).')"); // please use a prepared statement instead, just a proof of concept
$sum = $command->queryScalar();
echo $sum;
现在我在网上收到错误$ids[] = $model->id;}作为Getting unknown property: yii'db'ActiveQuery::id
是否尝试将此查询直接添加到ActiveDataprovider？正如这里所解释的，指定额外的查询部分是可能的，这应该是一个可能的解决方案。或者，您可以尝试从ActiveDataprovider中提取结果的ID，并使用它们来修改辅助查询。
第二种方法示例：
// You should make sure that the same parameters are passed to
// the GridView's ActiveDataProvider and the Model's find() function
$idQuery = Estimate::find()->all();
$ids = [];
foreach ($idQuery as $i => $model) {
$ids[] = $model['id'];
}
$command = Yii::$app->db->createCommand('SELECT sum(net_total) FROM estimate WHERE `id` IN ('.implode(',',$ids).')'); // please use a prepared statement instead, just a proof of concept
$sum = $command->queryScalar();