MySQL将JSON值从类型'OBLOG'更改为'ARRAY'

yqkkidmi  于 12个月前  发布在  Mysql
关注(0)|答案(3)|浏览(133)

救命啊!救命啊!我有一个MySQL表,其中有一个JSON列。不久前我推送了一个过滤PHP数组的更改,但没有重置数组键,因此当它转换为JSON时,数组被存储为对象。我有一个我需要转换这个例如:

{
  "recipients": {
    "1": {
      "name": "Alice", 
      "email": "[email protected]"
    }, 
    "2": {
      "name": "Bob",
      "email": "[email protected]"
    }
  },
  // ...
}

字符串

{
  "recipients": [
    {
      "name": "Alice", 
      "email": "[email protected]"
    }, 
    {
      "name": "Bob",
      "email": "[email protected]"
    }
  ],
  // ...
}


如果可能的话,我想在查询中进行这种转换。

SELECT data 
FROM table1 
WHERE JSON_TYPE(JSON_EXTRACT(data, '$.recipients')) = 'OBJECT'


但是我坚持在不影响JSON中其他键的情况下进行转换和更新数据。这可以在查询中完成吗?或者我必须在PHP中进行转换?

flseospp

flseospp1#

SELECT JSON_PRETTY(
  JSON_OBJECT(
    "recipients", JSON_ARRAYAGG(
      JSON_EXTRACT(data, CONCAT('$.recipients."', k.rkey, '"'))
    )
  ) 
) AS _newjson
FROM table1
CROSS JOIN JSON_TABLE(JSON_KEYS(data, '$.recipients'), '$[*]' COLUMNS (rkey INT PATH '$')) k
WHERE JSON_TYPE(JSON_EXTRACT(data, '$.recipients')) = 'OBJECT';

字符串
输出给定的测试数据:

{
  "recipients": [
    {
      "name": "Alice",
      "email": "[email protected]"
    },
    {
      "name": "Bob",
      "email": "[email protected]"
    }
  ]
}

6rqinv9w

6rqinv9w2#

所有功劳都归功于Bill's answer做了繁重的工作。我只需要做一个调整-添加一个GROUP BY,这样聚合就不会合并组合所有行。
因为我使用JSON_SET来设置“recipients”键的值,所以子查询可以只返回转换后的值,而不需要JSON_OBSTATE(或JSON_PRETTY)。
下面是最后一个查询:

UPDATE table1
JOIN (
    SELECT
        entry_id, -- for joining back to the main table
        JSON_ARRAYAGG(JSON_EXTRACT(data, CONCAT('$.recipients."', k.recipients_key, '"'))) AS recipients
    FROM table1
    CROSS JOIN JSON_TABLE(JSON_KEYS(data, '$.recipients'), '$[*]' COLUMNS (recipients_key INT PATH '$')) k
    WHERE JSON_TYPE(JSON_EXTRACT(data, '$.recipients')) = 'OBJECT'
    GROUP BY entry_id -- important or it will combine all rows into a single result!
) AS fixed
ON fixed.entry_id = table1.entry_id
SET data = JSON_SET(data, '$.recipients', fixed.recipients)
WHERE JSON_TYPE(JSON_EXTRACT(data, '$.routed_to')) = 'OBJECT'

字符串

vsnjm48y

vsnjm48y3#

我发现了另一种提取值的方法,它不需要子查询,而且运行速度更快:

UPDATE table1
SET data = JSON_SET(
    data,
    '$.recipients',
    data->"$.recipients.*"
)
WHERE JSON_TYPE(JSON_EXTRACT(data, '$.recipients')) = 'OBJECT';

字符串
通过在所需JSON路径的末尾追加.*,我们可以将对象的值作为数组获取,并立即使用JSON_SET将它们写回相同的路径。

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