这是我的文档的样子:{"_id":ObjectId("583cb6bcce047d1e68339b64"),"variantDetails":[{"variants":{"_":"_"},"sku":"069563-59690"},{"variants":{"size":"35"},"sku":"069563-59690-35","barcode":"809702246941"},{"variants":{"size":"36"},"sku":"069563-59690-36","barcode":"809702246958"}......]}我想使用这样一个复杂的聚合查询:db.ge