Question 21616 in Mysql Question posted in
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How to get a specific object in an JSON array in MySQL?

I have a JSON column "jobs" that looks like this:

[
    {
      "id": "1",
      "done": "100",
      "target": "100",
      "startDate": "123123132",
      "lastAction": "123123132",
      "status": "0"
    },
    {
      "id": "2",
      "done": "10",
      "target": "20",
      "startDate": "2312321",
      "lastAction": "2312321",
      "status": "1"
    }
]

I want to filter the array by object key values. For example: To find all items that have target > done, status != 0 and lastAction is yesterday to get response like this:

[
    {
      "id": "1",
      "done": "19",
      "target": "100",
      "startDate": "123123132",
      "lastAction": "123123132",
      "status": "0"
    }
]

I know I can extract the data to a JSON_TABLE() to do the filtering but I don’t get the original object back(unless I recreate it back) and the solution is not dynamic.

Can this kind of array filtering can really be done in MySQL?

Tags:

2

Answers


  1. 0

    Yes it is possible to do it using the JSON_EXTRACT and JSON_SEARCH functions.

    Let’s say your table is named tbl_Jobs and the jobs column is of type JSON.

    SELECT * FROM tbl_Jobs
WHERE JSON_EXTRACT(jobs, "$[*].target") = JSON_EXTRACT(jobs, "$[*].done")
AND JSON_EXTRACT(jobs, "$[*].status") != 0
AND JSON_SEARCH(jobs, 'one', DATE_SUB(CURDATE(), INTERVAL 1 DAY), NULL, "$[*].lastAction") IS NOT NULL
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  2. 0 
    SELECT JSON_PRETTY(JSON_EXTRACT(jobs.jobs, CONCAT('$[', j.rownum-1, ']'))) AS object
FROM jobs
CROSS JOIN JSON_TABLE(
  jobs.jobs, '$[*]' COLUMNS(
    rownum for ordinality,
    done int path '$.done',
    target int path '$.target',
    status int path '$.status'
  )
) as j
WHERE j.target > j.done AND j.status != 0;

    You also mentioned a condition on lastAction, but the example values you gave are not valid dates, so I’ll leave that enhancement to you. The example above demonstrates the technique.

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