YIi2 - comparing two field in searchModel - yii2

Question

I have a table called TPurchasing which contain data about a store's purchasing record.
TPurchasing
id | serial
transaction_time | timestamp without time zone
supplier | character varying(200)
total | double precision
paid | double precision
By using gii feature in yii2, I manage to generate a model called TPurchasingSearch from "CRUD Generator" menu. In the TPurchasingSearch, there is a function called search() which is used by the GridView in the view file.
public function search($params)
{
$query = TPurchasing::find();
$dataProvider = new ActiveDataProvider([
'pagination' => ['pageSize' => 20],
'query' => $query,
'sort' => ['defaultOrder' => ['transaction_time' => SORT_DESC]]
]);
$this->load($params);
if (!$this->validate()) {
$query->where('0=1');
return $dataProvider;
}
$query->andFilterWhere(['is_removed' => 0]);
$query->andFilterWhere(['like', 'supplier_name', $this->supplier_name])
->andFilterWhere(['like', 'payment_type', $this->payment_type])
->andFilterWhere(['>', 'total', 'paid']);
return $dataProvider;
}
Right now I'm trying to display records that is still not totally paid off, which means the "paid" column is smaller than "total" column. How can I do this comparison in the search function? The above code gave me an error:
invalid input syntax for type double precision: "paid"
on this part
->andFilterWhere(['>', 'total', 'paid']);
since it tried to compare total column with string "paid". I might missed it, but I can't seem to find the related answer in Yii2 documentation.

Answer 1

No need to use andFilterWhere() here, you could simply try :
$query->andWhere('total > paid');