是否可以对JSON_VALUE使用通配符和范围? [英] Is it possible to use wildcards and ranges with JSON_VALUE?
问题描述
我目前正在研究一个使用Oracle 12c的JSON功能的示例,我正在努力了解如何在
I am currently working through an example of using the JSON features of Oracle 12c and I am struggling to understand how to use wildcards and ranges with JSON_VALUE.
示例我是使用来自《 Oracle Magazine》 2015年1月/2月号,这是我坚持使用的SQL.
The example I am using is from the January/February 2015 issue of Oracle Magazine and here is the SQL I am stuck on.
select json_value(t.trans_msg, '$.CheckDetails[0].CheckNumber'), -- works returns 101
json_value(t.trans_msg, '$.CheckDetails[*].CheckNumber'), -- null returned
json_value(t.trans_msg, '$.CheckDetails[0,1].CheckNumber') -- null returned
from transactions t
where t.id = 1
文章提到
...显示全部 值,Mark使用CheckDetails [*]. (他可以使用特定数字 拉特定的项目,例如CheckDetails [0,2]拉第一个 和第三项...
...To show all the values, Mark uses CheckDetails[*]. (He can use specific numbers to pull specific items—for example, CheckDetails[0,2] to pull the first and third items...
因此,我希望查询的第二行和第三行返回所有CheckNumber值(101和102).
So I am expecting that the second and third lines of the query return all the CheckNumber values (101 and 102).
我正在使用Oracle Database 12.1.0.2.0,如果需要,这是表和插入脚本:
I am using Oracle Database 12.1.0.2.0 and here is the table and insert script in case of need:
create table transactions(
id number not null primary key,
trans_msg clob,
constraint check_json check (trans_msg is json)
)
/
insert into transactions
(id,
trans_msg
)
VALUES
(1,
'{
"TransId" : 1,
"TransDate" : "01-JAN-2015",
"TransTime" : "11:05:00",
"TransType" : "Deposit",
"AccountNumber" : 123,
"AccountName" : "Smith, John",
"TransAmount" : 100.00,
"Location" : "ATM",
"CashierId" : null,
"ATMDetails" : {
"ATMId" : 301,
"ATMLocation" : "123 Some St, Danbury CT 06810"
},
"WebDetails" : {
"URL" : null
},
"Source" : "Check",
"CheckDetails" : [
{
"CheckNumber" : 101,
"CheckAmount" : 50.00,
"AcmeBankFlag" : true,
"Endorsed" : true
},
{
"CheckNumber" : 102,
"CheckAmount" : 50.00,
"AcmeBankFlag" : false,
"Endorsed" : true
}
]
}'
)
/
我知道我肯定想念一些明显的东西!
I know I must be missing something obvious!
推荐答案
JSON_VALUE
旨在返回标量.要返回JSON对象或关系数据,必须使用JSON_QUERY
或JSON_TABLE
.
JSON_VALUE
is meant to return scalars. To return JSON objects or relational data you must use JSON_QUERY
or JSON_TABLE
.
select json_query(t.trans_msg, '$.CheckDetails[0].CheckNumber' with wrapper) a,
json_query(t.trans_msg, '$.CheckDetails[*].CheckNumber' with wrapper) b,
json_query(t.trans_msg, '$.CheckDetails[0,1].CheckNumber' with wrapper) c
from transactions t
where t.id = 1;
A B C
----- --------- ---------
[101] [101,102] [101,102]
select id, details
from transactions
cross join json_table
(
trans_msg, '$.CheckDetails[*]'
columns
(
details path '$.CheckNumber'
)
);
ID DETAILS
-- -------
1 101
1 102
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