使用 JSON_MERGEPATCH 后更新 json 列
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【中文标题】使用 JSON_MERGEPATCH 后更新 json 列【英文标题】：Update a json column after use JSON_MERGEPATCH 【发布时间】：2021-01-30 22:35:20 【问题描述】：有这个
create table departments_json (
department_id
integer
NOT NULL
CONSTRAINT departments_json__id__pk PRIMARY KEY,
department_data
CLOB
NOT NULL
CONSTRAINT departments_json__data__chk CHECK ( department_data IS JSON )
);
insert into departments_json
json values ( 110, '
"department": "Accounting",
"employees": [
"name": "Higgins, Shelley",
"job": "Accounting Manager",
"hireDate": "2002-06-07T00:00:00"
,
"name": "Gietz, William",
"job": "Public Accountant",
"hireDate": "2002-06-07T00:00:00"
]
'
);
还有新的 json ：
"employees": [
"name": "Chen, John",
"job": "Accountant",
"hireDate": "2005-09-28T00:00:00"
,
"name": "Greenberg, Nancy",
"job": "Finance Manager",
"hireDate": "2002-08-17T00:00:00"
,
"name": "Urman, Jose Manuel",
"job": "Accountant",
"hireDate": "2006-03-07T00:00:00"
]
在POST 之后，回复对我帮助很大。但现在是时候用新的 json 更新列部门数据了。我正在使用这个查询：
update departments_json d
set d.department_data =
WITH employees ( json ) AS (
SELECT j.json
FROM departments_json d
CROSS APPLY JSON_TABLE(
d.department_data,
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
WHERE d.department_id = 110
UNION ALL
SELECT j.json
FROM JSON_TABLE(
'
employees: [
name: Chen, John,
job: Accountant,
hireDate: 2005-09-28T00:00:00
,
name: Greenberg, Nancy,
job: Finance Manager,
hireDate: 2002-08-17T00:00:00
,
name: Urman, Jose Manuel,
job: Accountant,
hireDate: 2006-03-07T00:00:00
]
',
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
)JSON_MERGEPATCH(
d.department_data,
(
SELECT JSON_OBJECT(
KEY 'employees'
VALUE JSON_ARRAYAGG( json FORMAT JSON RETURNING CLOB )
FORMAT JSON
)
FROM employees
)
)
WHERE d.department_id = 110;
但我得到了这个错误，我不知道哪里错了
错误：
Error en la línea de comandos : 3 Columna : 5
Informe de error -
Error SQL: ORA-00936: falta una expresión
00936. 00000 - "missing expression"
*Cause:
*Action:
怎么了，我按照这个步骤：LINK
注意：这是我的桌子的样子：
更新
应用 MP0 建议后，这就是我的查询的样子（两个选项）
但问题是我有这个错误：
ORA-40478: output value too large (maximum: 4000)
【问题讨论】：
【参考方案1】：你可以使用：
UPDATE departments_json
SET department_data = JSON_MERGEPATCH(
department_data,
(
SELECT JSON_OBJECT(
KEY 'employees'
VALUE JSON_ARRAYAGG( json FORMAT JSON RETURNING CLOB )
FORMAT JSON RETURNING CLOB
)
FROM (
SELECT j.json
FROM departments_json d
CROSS APPLY JSON_TABLE(
d.department_data,
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
WHERE d.department_id = 110
UNION ALL
SELECT j.json
FROM JSON_TABLE(
'
"employees": [
"name": "Chen, John",
"job": "Accountant",
"hireDate": "2005-09-28T00:00:00"
,
"name": "Greenberg, Nancy",
"job": "Finance Manager",
"hireDate": "2002-08-17T00:00:00"
,
"name": "Urman, Jose Manuel",
"job": "Accountant",
"hireDate": "2006-03-07T00:00:00"
]
',
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
)
)
RETURNING CLOB
)
WHERE department_id = 110;
输出：
DEPARTMENT_ID | DEPARTMENT_DATA ------------: | :------------------------------------------------ -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- -------------------------------------------------- ----- 110 | "department":"Accounting","employees":["name":"Higgins, Shelley","job":"Accounting Manager","hireDate":"2002-06-07T00:00:00" ,"name":"Gietz, William","job":"Public Accountant","hireDate":"2002-06-07T00:00:00","name":"Chen, John","工作":"会计","hireDate":"2005-09-28T00:00:00","name":"Greenberg, Nancy","job":"财务经理","hireDate":"2002 -08-17T00:00:00","name":"Urman, Jose Manuel","job":"Accountant","hireDate":"2006-03-07T00:00:00"]
db小提琴here
更新
您的代码有几个问题：
JSON_MERGEPATCH 需要环绕WITH ... SELECT 语句，因为该语句的输出应该是JSON_MERGEPATCH 的第二个参数；和
您的 JSON 无效，因为它缺少标识符和字符串周围的所有双引号。
如果你解决了这个问题，那么你的代码也可以工作：
update departments_json d
set d.department_data = JSON_MERGEPATCH(
d.department_data,
( -- Start of second argument of JSON_MERGEPATCH
WITH employees ( json ) AS (
SELECT j.json
FROM departments_json d
CROSS APPLY JSON_TABLE(
d.department_data,
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
WHERE d.department_id = 110
UNION ALL
SELECT j.json
FROM JSON_TABLE(
'
"employees": [
"name": "Chen, John",
"job": "Accountant",
"hireDate": "2005-09-28T00:00:00"
,
"name": "Greenberg, Nancy",
"job": "Finance Manager",
"hireDate": "2002-08-17T00:00:00"
,
"name": "Urman, Jose Manuel",
"job": "Accountant",
"hireDate": "2006-03-07T00:00:00"
]
',
'$.employees[*]'
COLUMNS (
json CLOB FORMAT JSON PATH '$'
)
) j
)
SELECT JSON_OBJECT(
KEY 'employees'
VALUE JSON_ARRAYAGG( json FORMAT JSON RETURNING CLOB )
FORMAT JSON RETURNING CLOB
)
FROM employees
) -- End of second argument of JSON_MERGEPATCH
RETURNING CLOB
)
WHERE d.department_id = 110;
db小提琴here
【讨论】：
再次您好（我更新我的问题），请根据我的情况调整此代码，我收到此错误：Informe de error - ORA-40478: output value too large （最大：4000）。就我而言，我有第一个 json 有 1000 名员工，第二个 json 有 900 多名员工。如果我执行 UNION ALL 我会看到我所有的员工 (1900)，但是当我使用更新部分执行时，它不起作用，可能是什么问题？问候 @Julio 字符串文字只能包含 4000 个字符。如果要传递超过 4000 个字符，则需要使用CLOB 或 BLOB（或将其拆分为小于 4000 个字符的块）。可能您只需要在JSON_OBJECT 函数调用的末尾添加RETURNING CLOB。如果不是这样，那么在您的代码中某处已达到此限制，您将需要调试您的代码以找出它在哪里。您可以获取部件（即休息请求、WITH ... SELECT 和 UPDATE）并单独运行它们检查输入值，如果有任何失败。
您好，如果您看到我的问题，我会使用两个选项上传第二张图片，并带有返回选项（clob），但错误是相同的。我必须存储大 json (1900) 员工，所以你有什么建议？问候
@Julio 尝试将第一个示例中最后一行的第 6 行（或第二个示例中的第 7 行）从 FORMAT JSON 更改为 FORMAT JSON RETURNING CLOB。
你是对的，它工作！非常感谢大家。 :)以上是关于使用 JSON_MERGEPATCH 后更新 json 列的主要内容，如果未能解决你的问题，请参考以下文章
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