MySQL之JSON型別欄位的使用技巧分享

CREATE TABLE json_demo ( 
	`id` INT ( 11 ) NOT NULL PRIMARY KEY, 
	`content` json NOT NULL 
);
INSERT INTO json_demo ( id, content )
VALUES
	/*這條是陣列*/
	( 1, '[{"key": 1, "order": 1, "value": "34252"},{"key": 2, "order": 2, "value": "23423"}]' ),
	/*這條是陣列*/
	( 2, '[{"key": 4, "order": 4, "value": "234"},{"key": 5, "order": 5, "value": "234324523"}]' ),
	/*這條是物件*/
	( 3, '{"key": 3, "order": 3, "value": "43242"}' ),
	/*這條是物件*/
	( 4, '{"key": 6, "order": 6, "value": "5423"}' );

/* 基礎查詢 */
SELECT
	content -> '$.key' AS 'key',
	JSON_EXTRACT(content, '$.key') AS 'key2',
	content -> '$.value' AS 'value',
	JSON_EXTRACT(content, '$.value') AS 'value2',
	content ->> '$.value' AS 'value3',
	JSON_UNQUOTE(JSON_EXTRACT(content, '$.value')) AS 'value4'
FROM
	json_demo 
WHERE
	id > 2;

SELECT
	id,
	content -> '$.key' AS 'key',
	content ->> '$.value' AS 'value3'
FROM
	json_demo 
WHERE
	id > 2
	AND content -> '$.key' > 1
	AND content -> '$.value' like '%2%';

/* 修改 */
UPDATE json_demo 
SET content = JSON_REPLACE(
	content,
	/* 將content.key值 + 1 */
	'$.key', content -> '$.key' + 1,
	/* 將content.value值後拼接'abc' */
	'$.value', concat(content ->> '$.value', 'abc')
) WHERE id = 3;
/* JSON_SET也可以 */
UPDATE json_demo 
SET content = JSON_SET(
	content,
	/* 將content.key值 + 1 */
	'$.key', content -> '$.key' + 1,
	/* 將content.value值後拼接'abc' */
	'$.value', concat(content ->> '$.value', 'abc')
) WHERE id = 3;
/* 查詢修改結果 */
SELECT id,content,content -> '$.key' AS 'key',content ->> '$.value' AS 'value3'
FROM json_demo WHERE id = 3;
/* 重新賦值 */
UPDATE json_demo SET 
content = JSON_REPLACE(content,'$.key',3,'$.value','43242') WHERE id = 3;

UPDATE json_demo 
SET content = JSON_INSERT(content, '$.key', 234)
WHERE id = 3;

SELECT id,content,content -> '$.key' AS 'key' FROM json_demo WHERE id = 3;

UPDATE json_demo 
SET content = JSON_INSERT(content, '$.temp', 234)
WHERE id = 3;

SELECT id,content,content -> '$.key' AS 'key' FROM json_demo WHERE id = 3;

UPDATE json_demo 
SET content = JSON_SET(content, '$.temp2', 432)
WHERE id = 3;

SELECT id,content,content -> '$.key' AS 'key' FROM json_demo WHERE id = 3;

SELECT
	id,
	content -> '$[*].key' AS 'key',
	content ->> '$[*].value' AS 'value',
	content -> '$[0].key' AS 'key2',
	content ->> '$[0].value' AS 'value2',
	/* 查詢陣列長度 */
	JSON_LENGTH(content) AS 'length'
FROM
	json_demo 
WHERE
	id < 3;

SELECT
	id,
	content -> '$[*].key' AS 'key',
	content ->> '$[*].value' AS 'value'
FROM
	json_demo 
WHERE
	id < 3
	/* content.value的值中存在like'%34%'的值 */
	AND content ->> '$[*].value' like '%34%'
	/* content.key的值中有4 */
	AND JSON_OVERLAPS(content ->> '$[*].key', '4' );