[Cb5.0] OBJECT/ATTRIBUTE META() 정보 및 KEY(ID) 조회

/*******************************************************************************************************************
-- Title : [Cb5.0] OBJECT/ATTRIBUTE META() 정보 및 KEY(ID) 조회
-- Reference : couchbase.com
-- Key word : meta() meta key id 메타 키 아이디 조회 couchbase 카우치베이스 N1QL n1ql object attribute
                 object_length object_names length is missing use keys
*******************************************************************************************************************/

■ META() 정보

-- META 정보 조회(KEY 출력 가능)
SELECT meta().*
FROM `travel-sample` 
WHERE type="hotel" 
LIMIT 1;
 
-- KEY(ID) 조회
-- META().id에서 id는 반드시 소문자여야 함
SELECT META().id as docid, *
FROM `travel-sample` 
LIMIT 10;
 
-- KEY(ID) 조회
SELECT *
FROM `travel-sample` 
USE KEYS ("hotel_10026");
 
SELECT *
FROM `travel-sample` 
USE KEYS ["hotel_10026", "hotel_16442"];
 
SELECT *
FROM `travel-sample` 
WHERE META().id = "hotel_10026";
 
SELECT *
FROM `travel-sample` 
WHERE META().id in ["hotel_10026", "hotel_16442"];

 
■ Attribute 정보

SELECT META().id as ID
     , OBJECT_LENGTH(aa) as ATTRIBTE_COUNT
     , OBJECT_NAMES(aa) as ATTRIBTE_NAMES
     , aa.country, length(aa.country) as ATTRIBTE_LENGTH
     , aa.country is missing as FILED_MISSING_NO
     , aa.ttt is missing as FILED_MISSING_YES
FROM `travel-sample` aa
WHERE META().id = "airline_10";

 
    o length() : UTF-8 기준으로 영문 1byte, 한글 3byte 계산