curd的api怎么查字段为空或非空

// Where & Order 参数示例
{
    "Where": [
        {
            "field": "AAA",
            "op": "Between",
            "value": "2022-02-2 00:00:00",
            "value1": "2022-02-24 00:00:00",
            "NAND" : "And"
        }

    ],
    "Order" :[
        {
            "field": "BBB",
            "ASC": 1
        }
    ]
}

但不会查空或非空