expression: add builtin function json_pretty

[jianzhiyao]

What problem does this PR solve?

Issue Number: part of #14486

Problem Summary:

add builtin function json_pretty

What is changed and how it works?

add builtin function json_pretty

Check List

Tests

• Unit test
• Integration test

Integration test

Preparation

use test;
drop table if exists t;
CREATE TABLE t  (`id` int NOT NULL AUTO_INCREMENT, `j` json,vc VARCHAR(500) ,  PRIMARY KEY (`id`));
INSERT INTO t ( id, j, vc )
VALUES
	( 1, '{"a":1,"b":"qwe","c":[1,2,3,"123",null],"d":{"d1":1,"d2":2}}', '{"a":1,"b":"qwe","c":[1,2,3,"123",null],"d":{"d1":1,"d2":2}}' ),
	( 2, '[1,2,34]', '{' );

Run in mysql

select JSON_PRETTY(t.j),JSON_PRETTY(vc) from  t where id = 1;
select JSON_PRETTY(t.j),JSON_PRETTY(vc) from  t where id = 2;
select JSON_PRETTY("[1,2,3]}");
Database changed
Query OK, 0 rows affected (0.01 sec)

Query OK, 0 rows affected (0.01 sec)

Query OK, 2 rows affected (0.00 sec)
Records: 2  Duplicates: 0  Warnings: 0

+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
| JSON_PRETTY(t.j)                                                                                           | JSON_PRETTY(vc)                                                                                            |
+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
| {
  "a": 1,
  "b": "qwe",
  "c": [
    1,
    2,
    3,
    "123",
    null
  ],
  "d": {
    "d1": 1,
    "d2": 2
  }
} | {
  "a": 1,
  "b": "qwe",
  "c": [
    1,
    2,
    3,
    "123",
    null
  ],
  "d": {
    "d1": 1,
    "d2": 2
  }
} |
+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
1 row in set (0.06 sec)

Invalid JSON text in argument 1 to function json_pretty: "Missing a name for object member." at position 1.
Invalid JSON text in argument 1 to function json_pretty: "The document root must not be followed by other values." at position 7.

Run in tidb

select JSON_PRETTY(t.j),JSON_PRETTY(vc) from  t where id = 1;
select JSON_PRETTY(t.j),JSON_PRETTY(vc) from  t where id = 2;
select JSON_PRETTY("[1,2,3]}");
Database changed
Query OK, 0 rows affected (0.01 sec)

Query OK, 0 rows affected (0.01 sec)

Query OK, 2 rows affected (0.01 sec)
Records: 2  Duplicates: 0  Warnings: 0

+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
| JSON_PRETTY(t.j)                                                                                           | JSON_PRETTY(vc)                                                                                            |
+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
| {
  "a": 1,
  "b": "qwe",
  "c": [
    1,
    2,
    3,
    "123",
    null
  ],
  "d": {
    "d1": 1,
    "d2": 2
  }
} | {
  "a": 1,
  "b": "qwe",
  "c": [
    1,
    2,
    3,
    "123",
    null
  ],
  "d": {
    "d1": 1,
    "d2": 2
  }
} |
+------------------------------------------------------------------------------------------------------------+------------------------------------------------------------------------------------------------------------+
1 row in set (0.05 sec)

3140 - Invalid JSON text: The document root must not be followed by other values.
3140 - Invalid JSON text: The document root must not be followed by other values.

Side effects

• Performance regression
  • Consumes more CPU
  • Consumes more MEM

Release note

• add builtin function json_pretty

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[ti-srebot]

No release note, Please follow https://github.com/pingcap/community/blob/master/contributors/release-note-checker.md

[jianzhiyao]

/run-check_release_note

[morgo]

@jiangyuzhao Thank you for adding this, it's very useful!

May I ask that you add some tests, such as:

• An integration test showing json_pretty applied on a column with the JSON data type.
• An integration test showing json_pretty applied to a varchar column (with inconsistent formatting)
• An integration test showing json_pretty applied to invalid JSON data, showing the same error as MySQL.

[jianzhiyao]

@jiangyuzhao Thank you for adding this, it's very useful!

May I ask that you add some tests, such as:

• An integration test showing json_pretty applied on a column with the JSON data type.
• An integration test showing json_pretty applied to a varchar column (with inconsistent formatting)
• An integration test showing json_pretty applied to invalid JSON data, showing the same error as MySQL.

I make some test in tidb and mysql.
And I found their behavior is different when applying to invalid JSON data, which seems belong to another compatibility problem.

[morgo]

@jiangyuzhao Thank you for adding this, it's very useful!
May I ask that you add some tests, such as:

• An integration test showing json_pretty applied on a column with the JSON data type.
• An integration test showing json_pretty applied to a varchar column (with inconsistent formatting)
• An integration test showing json_pretty applied to invalid JSON data, showing the same error as MySQL.

I make some test in tidb and mysql.
And I found their behavior is different when applying to invalid JSON data, which seems belong to another compatibility problem.

Can you add the tests in the PR description to expression/integration_test.go. This will allow us to run the tests automatically. Thanks!

[jianzhiyao]

PTAL @morgo

[morgo]

LGTM (non binding)

Sorry, I am not a component/expression reviewer. I will bring it up in #sig-exec on TiDB community slack.

[jianzhiyao]

/run-check_dev_2

[jianzhiyao]

PTAL again @pingyu

[pingyu]

/lgtm

[jianzhiyao]

PTAL again @lzmhhh123

[ti-chi-bot]

[REVIEW NOTIFICATION]

This pull request has been approved by:

• lzmhhh123
• pingyu

To complete the pull request process, please ask the reviewers in the list to review by filling /cc @reviewer in the comment.
After your PR has acquired the required number of LGTMs, you can assign this pull request to the committer in the list by filling /assign @committer in the comment to help you merge this pull request.

The full list of commands accepted by this bot can be found here.

Reviewer can indicate their review by writing /lgtm in a comment.
Reviewer can cancel approval by writing /lgtm cancel in a comment.

[lzmhhh123]

/merge

[ti-chi-bot]

This pull request has been accepted and is ready to merge.

Commit hash: b690785

[jianzhiyao]

Why the uint-test fails so many time? i can not get any useful info in error message
@lzmhhh123

[ti-chi-bot]

@jianzhiyao: Your PR was out of date, I have automatically updated it for you.

At the same time I will also trigger all tests for you:

/run-all-tests

If the CI test fails, you just re-trigger the test that failed and the bot will merge the PR for you after the CI passes.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the ti-community-infra/tichi repository.

[jianzhiyao]

/run-unit-test