Bagaimana untuk mengemas kini lajur jenis data JSON dalam MySQL 5.7.10?

Question

Saya baru-baru ini mula menggunakan MySQL 5.7.10 dan saya sangat menyukai jenis data JSON asli.

Tetapi saya menghadapi masalah semasa mengemas kini nilai jenis JSON.

Soalan:

Berikut adalah format jadual, di sini saya ingin menggunakan data 列中为 t1 表添加 1 个键。现在我必须获取值修改它并更新表。所以就涉及到一个额外的SELECTpenyata.

Boleh selit macam ni

INSERT INTO t1 values ('{"key2":"value2"}', 1);

mysql> select * from t1;
+--------------------+------+
| data               | id   |
+--------------------+------+
| {"key1": "value1"} |    1 |
| {"key2": "value2"} |    2 |
| {"key2": "value2"} |    1 |
+--------------------+------+
3 rows in set (0.00 sec)

mysql>Show create table t1;


+-------+-------------------------------------------------------------

-------------------------------------------------------+
| Table | Create Table                                                                                                       |
+-------+--------------------------------------------------------------------------------------------------------------------+
| t1    | CREATE TABLE `t1` (
  `data` json DEFAULT NULL,
  `id` int(11) DEFAULT NULL
) ENGINE=InnoDB DEFAULT CHARSET=latin1 |
+-------+--------------------------------------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

Adakah penyelesaiannya?

Answer 1

Kini dengan MySQL 5.7.22+, sangat mudah dan mudah untuk mengemas kini keseluruhan serpihan json (berbilang nilai kunci, malah bersarang) dalam satu pertanyaan, seperti ini:

update t1 set data = 
JSON_MERGE_PATCH(`data`, '{"key2": "I am ID2", "key3": "I am ID3"}') where id = 2;

Semoga ia membantu melawat halaman ini dan mencari yang "lebih baik" JSON_SET :) Maklumat lanjut tentang JSON_MERGE_PATCH di sini: https://dev.mysql .com/doc/refman/5.7/en/json-modification-functions.html#function_json-merge-patch

Answer 2

Terima kasih kepada @wchiquito kerana menunjukkan saya ke arah yang betul. Saya menyelesaikan masalah ini. Ini adalah cara saya melakukannya.

mysql> select * from t1;
+----------------------------------------+------+
| data                                   | id   |
+----------------------------------------+------+
| {"key1": "value1", "key2": "VALUE2"}   |    1 |
| {"key2": "VALUE2"}                     |    2 |
| {"key2": "VALUE2"}                     |    1 |
| {"a": "x", "b": "y", "key2": "VALUE2"} |    1 |
+----------------------------------------+------+
4 rows in set (0.00 sec)

mysql> update t1 set data = JSON_SET(data, "$.key2", "I am ID2") where id = 2;
Query OK, 1 row affected (0.04 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from t1;
+----------------------------------------+------+
| data                                   | id   |
+----------------------------------------+------+
| {"key1": "value1", "key2": "VALUE2"}   |    1 |
| {"key2": "I am ID2"}                   |    2 |
| {"key2": "VALUE2"}                     |    1 |
| {"a": "x", "b": "y", "key2": "VALUE2"} |    1 |
+----------------------------------------+------+
4 rows in set (0.00 sec)

mysql> update t1 set data = JSON_SET(data, "$.key3", "I am ID3") where id = 2;
Query OK, 1 row affected (0.07 sec)
Rows matched: 1  Changed: 1  Warnings: 0

mysql> select * from t1;
+------------------------------------------+------+
| data                                     | id   |
+------------------------------------------+------+
| {"key1": "value1", "key2": "VALUE2"}     |    1 |
| {"key2": "I am ID2", "key3": "I am ID3"} |    2 |
| {"key2": "VALUE2"}                       |    1 |
| {"a": "x", "b": "y", "key2": "VALUE2"}   |    1 |
+------------------------------------------+------+
4 rows in set (0.00 sec)

---

Edit: Jika anda ingin menambah tatasusunan, gunakan JSON_ARRAY seperti

update t1 set data = JSON_SET(data, "$.key4", JSON_ARRAY('Hello','World!')) where id = 2;