regex_replace 函数跳过 NULL 值之后的任何内容

Posted 2023-03-29

【中文标题】regex_replace 函数跳过 NULL 值之后的任何内容

【英文标题】：regex_replace function skips anything coming after a NULL value

【发布时间】：2021-02-27 20:30:59

【问题描述】：

在我的配置单元表“ticket_full”中，我有一个名为“service_id”的 json 类型列，我想在 3 列中提取它，就像这样

["position":"1","typeid":"ROUTNAME","value":"PWAW13197","position":"2","typeid":"CDCNAME","value":null,"position":"3","typeid":"SVCNAME","value":"Business","position":"4","typeid":"USID","value":"FI021MLQE4"]

["position":"1","typeid":"ROUTNAME","value":"KHLA30076","position":"2","typeid":"CDCNAME","value":"eff-e-rjh-sw-cs2","position":"3","typeid":"SVCNAME","value":"Managed LAN","position":"4","typeid":"USID","value":"SA00BNGH0E"]

["position":"1","typeid":"NUMLIAPTT","value":"0492212984","position":"2","typeid":null,"value":null,"position":"3","typeid":null,"value":null,"position":"4","typeid":null,"value":null]

我使用了下面的代码：

SELECT get_json_object(single_json_table.identifiant_produit, '$.position') AS position,
  get_json_object(single_json_table.identifiant_produit, '$.typeid') AS typeid,
  get_json_object(single_json_table.identifiant_produit, '$.value') AS value
  FROM   
(SELECT explode(split(regexp_replace(substr(serviceid, 2, length(serviceid)-2),
            '",\\"', '",,,,"'), ',,,,')  ) as identifiant_produit 
  FROM ticket_full) single_json_table

它可以工作，但每次有一个值为 NULL 时，它都会忽略后面的内容并转到下一个字段： 示例：

请问有人知道怎么解决吗？

【参考方案1】：

这是因为 null 没有双引号，而您将这个 '",\\"' 替换为这个 '",,,,"'

尝试在正则表达式模式中删除 之前的双引号并相应地替换字符串，然后它也适用于带引号的值和空值：

split(regexp_replace(substr(serviceid, 2, length(serviceid)-2),
            ',\\"', ',,,,"'), ',,,,')