从 Oracle 表中的 CLOB 数据类型字段中提取文本

Question

有人可以建议如何从下面的字段中提取文本吗？它是一个 JSON 文件，作为 CLOB 数据类型字段存储在 Oracle 表中。

字段名称为Rules，其值如下：

{
   "condition":[
      {
         "name":"",
         "property":"ipaddress",
         "type":"range",
         "operator":"range",
         "start":"2.117.11.1",
         "end":"2.117.11.254"
      }
   ],
   "operator":{
      "property":"or"
   },
   "outcome":{
      "name":"BRSBRS",
      "reason":"Site was created on Fri Apr 20 2018 09:45:46 GMT+0100 (GMT Daylighttime)"
   }
}

我想从上面的两个不同字段中提取两个IP地址，如下所示：

Answer 1

假设您的字符串中有错字，实际上它是一个有效的 JSON 文档（意思是：您在 "condition" 之后缺少一个冒号，您可以使用自 Oracle 12.1 起可用的 json_table() 函数.

create table tbl (id number primary key, rules clob);
insert into tbl (id, rules) 
  select 1001,  '{"condition":[{"name":"","property":"ipaddress","type":"range","operator":"range","start":"2.117.11.1","end":"2.117.11.254"}],"operator":{"property":"or"},"outcome": {"name":"BRSBRS","reason":"Site was created on Fri Apr 20 2018 09:45:46 GMT+0100 (GMT Daylighttime)"}}'
  from   dual;

select id, start_ip_address, end_ip_address
from   tbl,
       json_table(rules format json, '$.condition[*]'
           columns start_ip_address varchar2(19) path '$.start',
                   end_ip_address   varchar2(19) path '$.end'
      )
;

  ID  START_IP_ADDRESS  END_IP_ADDRESS
----  ----------------  ----------------
1001  2.117.11.1        2.117.11.254