如果使用N1QL查询未找到结果，如何在长沙发数据库中获取文件名（列名）？

Question

我正在编写查询以在Couchbase中查找用户信息，我将结果获取为空数组，但我希望字段具有空结果，我曾尝试过几次，但无法获得具有空值。如何获取标题字段？

我的查询是

SELECT C.firstName AS `First Name`,
C.surName `Last Name`,
U.auditDetail.createTime AS `Date/Time of the Registration`
C.contactDetails.`email`.`value` AS `Email Address`,
C.contactDetails.`phone`.`value` AS ‘Phone Number`,
C.sex `Gender`,
C.dob AS `Data of Birth`,
ag.id AS `Referral Code`,
C.addressDetails.`office_new`.`zipcode` AS ‘Postal Code`,
C.addressDetails.`office_new.`city` AS `City`
FROM data C
UNNEST C.activeGroups AS ag
JOIN data_PH U ON U.loginld=C.contactDetails.`email`.`value`
WHERE U.type_='user'
AND C.type_= ‘customer`

结果：

{
  "results": []
}

Answer 1

执行查询时，签名具有字段的标题

SELECT
C.firstName AS `First Name`,
C.surName `Last Name`,
U.auditDetail.createTime AS `Date/Time of the Registration`,
C.contactDetails.`email`.`value` AS `Email Address`,
C.contactDetails.`phone`.`value` AS `Phone Number`,
C.sex `Gender`,
C.dob AS `Data of Birth`,
ag.id AS `Referral Code`,
C.addressDetails.`office_new`.`zipcode` AS `Postal Code`,
C.addressDetails.`office_new`.`city` AS City
FROM default AS C
UNNEST C.activeGroups AS ag
JOIN default AS U ON U.loginld=C.contactDetails.`email`.`value`
WHERE U.type_="user"
AND C.type_= "customer";

{
    "requestID": "c4a806b6-b3d7-4172-8b60-ebe195d00cef",
    "signature": {
        "City": "json",
        "Data of Birth": "json",
        "Date/Time of the Registration": "json",
        "Email Address": "json",
        "First Name": "json",
        "Gender": "json",
        "Last Name": "json",
        "Phone Number": "json",
        "Postal Code": "json",
        "Referral Code": "json"
    },
    "results": [
    ],
    "status": "success",
    "metrics": {
        "elapsedTime": "9.723082ms",
        "executionTime": "9.616195ms",
        "resultCount": 0,
        "resultSize": 0
    }
}