第一标题
1、JSON_ARRAY_APPEND数组类的追加
这个用法主要是处理JSON字段中值数组型的数据,主要是追加值,不是标准数组类型的,这个函数会自动转化为数组形式,把之前的值作为数组的第一个元素然后进行追加,有批量追加方法:
mysql> SET @j = '["a", ["b", "c"], "d"]';
在字段中第二个数值的数组中追加一个元素1:
mysql> SELECT JSON_ARRAY_APPEND(@j, '$[1]', 1); +----------------------------------+ | JSON_ARRAY_APPEND(@j, '$[1]', 1) | +----------------------------------+ | ["a", ["b", "c", 1], "d"] | +----------------------------------+
在字段中第一个数值的数组中追加一个元素2,如果不是数组形式的单个值会改变其为数组并追加:
mysql> SELECT JSON_ARRAY_APPEND(@j, '$[0]', 2); +----------------------------------+ | JSON_ARRAY_APPEND(@j, '$[0]', 2) | +----------------------------------+ | [["a", 2], ["b", "c"], "d"] | +----------------------------------+
在字段中第二个数值的第一个数组中追加一个元素3,如果不是数组形式的单个值会改变其为数组并追加:
mysql> SELECT JSON_ARRAY_APPEND(@j, '$[1][0]', 3); +-------------------------------------+ | JSON_ARRAY_APPEND(@j, '$[1][0]', 3) | +-------------------------------------+ | ["a", [["b", 3], "c"], "d"] | +-------------------------------------+
在字段中key为”b”的value数组中追加一个元素”x”:
mysql> SET @j = '{"a": 1, "b": [2, 3], "c": 4}'; mysql> SELECT JSON_ARRAY_APPEND(@j, '$.b', 'x'); +------------------------------------+ | JSON_ARRAY_APPEND(@j, '$.b', 'x') | +------------------------------------+ | {"a": 1, "b": [2, 3, "x"], "c": 4} | +------------------------------------+
在字段中key为”c”的value数组中追加一个元素”y”:
mysql> SELECT JSON_ARRAY_APPEND(@j, '$.c', 'y'); +--------------------------------------+ | JSON_ARRAY_APPEND(@j, '$.c', 'y') | +--------------------------------------+ | {"a": 1, "b": [2, 3], "c": [4, "y"]} | +--------------------------------------+
如果JSON字段为标准的JSON类型,使用这个函数则会把其变化数组形式,并追加值:
mysql> SET @j = '{"a": 1}'; mysql> SELECT JSON_ARRAY_APPEND(@j, '$', 'z'); +---------------------------------+ | JSON_ARRAY_APPEND(@j, '$', 'z') | +---------------------------------+ | [{"a": 1}, "z"] | +---------------------------------+
如果JSON字段为标准的JSON类型,批量追加:
mysql> SELECT JSON_ARRAY_APPEND(@j, '$', 'z','$', 'w'); +---------------------------------+ | JSON_ARRAY_APPEND(@j, '$', 'z') | +---------------------------------+ | [{"a": 1}, "z", "w"] | +---------------------------------+
2、JSON_ARRAY_INSERT数组类的插入
这个用法主要是处理JSON字段中值数组型的数据,主要是插入,不是标准数组类型的,这个函数会自动转化为数组形式,把之前的值作为数组的第一个元素然后进行追加:
mysql> SET @j = '["a", {"b": [1, 2]}, [3, 4]]';
在数组第1个值后面插入字符’x’ 元素:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[1]', 'x'); +------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[1]', 'x') | +------------------------------------+ | ["a", "x", {"b": [1, 2]}, [3, 4]] |
在数组第1个值前面插入字符’x’ 元素:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[0]', 'x'); +------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[1]', 'x') | +------------------------------------+ | ["x","a", {"b": [1, 2]}, [3, 4]] | +------------------------------------+
在数组第100个值后面插入字符’x’ 元素,如果超长,则在最后一个值后面插入:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[100]', 'x'); +--------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[100]', 'x') | +--------------------------------------+ | ["a", {"b": [1, 2]}, [3, 4], "x"] | +--------------------------------------+
在数组第1个值中key为’b’的value数组第1个值前面入字符元素’x’:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[1].b[0]', 'x'); +-----------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[1].b[0]', 'x') | +-----------------------------------------+ | ["a", {"b": ["x", 1, 2]}, [3, 4]] | +-----------------------------------------+
在数组第2个值后面数组第1个值后面入字符元素’y’:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[2][1]', 'y'); +---------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[2][1]', 'y') | +---------------------------------------+ | ["a", {"b": [1, 2]}, [3, "y", 4]] | +---------------------------------------+
数组元素的批量插入:
mysql> SELECT JSON_ARRAY_INSERT(@j, '$[0]', 'x', '$[2][1]', 'y'); +----------------------------------------------------+ | JSON_ARRAY_INSERT(@j, '$[0]', 'x', '$[2][1]', 'y') | +----------------------------------------------------+ | ["x", "a", {"b": [1, 2]}, [3, 4]] | +----------------------------------------------------+
3、JSON_INSERT标准JSON值的插入
如果这个key已经存在,则不会去覆盖旧值,不存在的插入:
mysql> SET @j = '{ "a": 1, "b": [2, 3]}'; mysql> SELECT JSON_INSERT(@j, '$.a', 10, '$.c', '[true, false]'); +----------------------------------------------------+ | JSON_INSERT(@j, '$.a', 10, '$.c', '[true, false]') | +----------------------------------------------------+ | {"a": 1, "b": [2, 3], "c": "[true, false]"} | +----------------------------------------------------+
4、JSON_MERGE合并操作
JSON_MERGE这个主要用于合并:如果两个是数组的,则合并为一个数组;如果两个是JSON的,则合并为一个JSON,如果两个JSON有相同的key,则value合并为数组;如果是两个单值的,则合并为一个数组;如果是一个数组,一个是JSON,则合并为一个数组:
mysql> SELECT JSON_MERGE('[1, 2]', '[true, false]'); +---------------------------------------+ | JSON_MERGE('[1, 2]', '[true, false]') | +---------------------------------------+ | [1, 2, true, false] | +---------------------------------------+ mysql> SELECT JSON_MERGE('{"name": "x"}', '{"id": 47}'); +-------------------------------------------+ | JSON_MERGE('{"name": "x"}', '{"id": 47}') | +-------------------------------------------+ | {"id": 47, "name": "x"} | +-------------------------------------------+ mysql> SELECT JSON_MERGE('{"id": "x"}', '{"id": 47}'); +-------------------------------------------+ | JSON_MERGE('{"id": "x"}', '{"id": 47}') | +-------------------------------------------+ | {"id": ["x",47]} | +-------------------------------------------+ mysql> SELECT JSON_MERGE('1', 'true'); +-------------------------+ | JSON_MERGE('1', 'true') | +-------------------------+ | [1, true] | +-------------------------+ mysql> SELECT JSON_MERGE('[1, 2]', '{"id": 47}'); +------------------------------------+ | JSON_MERGE('[1, 2]', '{"id": 47}') | +------------------------------------+ | [1, 2, {"id": 47}] | +------------------------------------+
5、JSON_REMOVE删除操作
JSON_REMOVE删除操作,这个比较简单,删除字段中某个值,数组的或是JSON格式的都可以:
mysql> SET @j = '["a", ["b", "c"], "d"]'; mysql> SELECT JSON_REMOVE(@j, '$[1]'); +-------------------------+ | JSON_REMOVE(@j, '$[1]') | +-------------------------+ | ["a", "d"] | +-------------------------+ mysql> SET @j = '{"name": "x","id": 47}'; mysql> SELECT JSON_REMOVE(@j, '$.id'); +-------------------------+ | JSON_REMOVE(@j, '$.id') | +-------------------------+ | {"name": "x"} | +-------------------------+ mysql> SELECT JSON_REMOVE(@j, '$.id', '$.name'); +-----------------------------------+ | JSON_REMOVE(@j, '$.id', '$.name') | +-----------------------------------+ | {} | +-----------------------------------+ mysql> SET @j = '{"name": "x","id": [47,48]}'; mysql> SELECT JSON_REMOVE(@j, '$.id[1]'); +-------------------------+ | JSON_REMOVE(@j, '$.id') | +-------------------------+ | {"id": [47],"name": "x"} | +-------------------------+
6、JSON_REPLACE操作
JSON_REPLACE替换操作,有则替换,无则忽略。
mysql> SET @j = '{ "a": 1, "b": [2, 3]}'; mysql> SELECT JSON_REPLACE(@j, '$.a', 10, '$.c', '[true, false]'); +-----------------------------------------------------+ | JSON_REPLACE(@j, '$.a', 10, '$.c', '[true, false]') | +-----------------------------------------------------+ | {"a": 10, "b": [2, 3]} +-----------------------------------------------------+ mysql> SELECT JSON_REPLACE(@j, '$.a', 10, '$.b[1]',99); +-----------------------------------------------------+ | JSON_REPLACE(@j, '$.a', 10, '$.b[1]',99') | +-----------------------------------------------------+ | {"a": 10, "b": [2, 99]} | +-----------------------------------------------------+
7、JSON_SET操作
JSON_SET操作为更新和插入操作,已经存在的去更新;不存在则插入,以下是JSON_SET、JSON_INSERT、JSON_REPLACE执行结果的区别:
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