如何從MySQL提取JSON數組

Question

我打算出於動態目的將JSON數組插入數據庫表。 在提取具有鍵/值對的JSON對象時，我沒有任何問題，但是與JSON數組相反。 請參見以下示例：

[{"LCM": {"id": 333, "barcode": "ABC"}, "DCover": {"id": 444, "barcode": "CDE"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 555, "barcode": "EFG"}, "DCover": {"id": 666, "barcode": "GHI"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"}]

理想情況下，如果將每個以上提取出來，則它們看起來都是這樣的：

{"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"}

現在的問題是，我怎么能這樣提取它們：

1. {"LCM": {"id": 333, "barcode": "ABC"}, "DCover": {"id": 444, "barcode": "CDE"}, "date_associated": "2017-11-27 23:59:59"}
2. {"LCM": {"id": 555, "barcode": "EFG"}, "DCover": {"id": 666, "barcode": "GHI"}, "date_associated": "2017-11-27 23:59:59"}
3. {"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"}

通過它們中的哪個，我將能夠根據需要進行解析，即：“ $。LCM”或“ $ .DCover.barcode”

似乎只能通過定義特定JSON對象的鍵來使用JSON_EXTRACT（ ... ）。 但這不適用於僅值JSON數組（據我所知）

希望我能在這里給小費。 謝謝。

Answer 1

如果您使用的是MySQL> = 8.0.4，則可以使用JSON_TABLE 。

查詢示例

with tbl(val) as (
  select CAST('[{"LCM": {"id": 333, "barcode": "ABC"}, "DCover": {"id": 444, "barcode": "CDE"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 555, "barcode": "EFG"}, "DCover": {"id": 666, "barcode": "GHI"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"}]'
  as json
 )
)
select rowid, content from tbl, JSON_TABLE(val, '$[*]' columns (rowid for ordinality, content json PATH '$')) as jt;

結果

+-------+---------------------------------------------------------------------------------------------------------------------------+
| rowid | content                                                                                                                   |
+-------+---------------------------------------------------------------------------------------------------------------------------+
|     1 | {"LCM": {"id": 333, "barcode": "ABC"}, "DCover": {"id": 444, "barcode": "CDE"}, "date_associated": "2017-11-27 23:59:59"} |
|     2 | {"LCM": {"id": 555, "barcode": "EFG"}, "DCover": {"id": 666, "barcode": "GHI"}, "date_associated": "2017-11-27 23:59:59"} |
|     3 | {"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"} |
+-------+---------------------------------------------------------------------------------------------------------------------------+

Answer 2

 According to my understand you are using JSON Array, use iteration

 CREATE PROCEDURE `Manipulation_Json_Data`()
  LANGUAGE SQL
  NOT DETERMINISTIC
  CONTAINS SQL
  SQL SECURITY DEFINER
  COMMENT ''
  BEGIN
  DECLARE v1 INT DEFAULT 0;

  SET @j = '[{"LCM": {"id": 333, "barcode": "ABC"}, "DCover": {"id": 444, "barcode": "CDE"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 555, "barcode": "EFG"}, "DCover": {"id": 666, "barcode": "GHI"}, "date_associated": "2017-11-27 23:59:59"}, {"LCM": {"id": 777, "barcode": "IJK"}, "DCover": {"id": 888, "barcode": "KLM"}, "date_associated": "2017-11-27 23:59:59"}]';

   WHILE v1 < 4 DO
     SET @data_v = JSON_EXTRACT(@j, concat('$[',v1,']'));
     INSERT INTO database.table_name (`ID`, `Text`) VALUES (NULL, @data_v );
     SET v1 = v1 + 1;
   END WHILE;
  END