MySQL 嵌套JSON解析

MySQL自5.7之后开始支持json类型，相应的解析函数主要是json_extract()。

查询MySQL版本

select version()

示例

示例json1

未经过转义的json串

{"l1":{"l1_1":["l1_1_1","l1_1_2"],"l1_2":{"l1_2_1":121,"l1_2_2":"122"}},"l2":{"l2_1":null,"l2_2":true,"l2_3":{}}}

示例json2

经过转义后的json串

{"t_key":"haha","t_value":"{\"id\":\"14\",\"timestamp\":1539768556,\"type\":1}","test":2}

通过json_extract()可以获取json里面value对于的值:

mysql> select json_extract(field1, '$.t_key') from table1;
+----------------------------------------+
| json_extract(field1, '$.t_key')        |
+----------------------------------------+
| "haha"                                 |
+----------------------------------------+
1 row in set (0.00 sec)

mysql> select json_extract(field1, '$.t_value') from table1;
+-------------------------------------------------------+
| json_extract(field1, '$.t_value')              |
+-------------------------------------------------------+
| "{\"id\":\"14\",\"timestamp\":1539768556,\"type\":1}" |
+-------------------------------------------------------+
1 row in set (0.00 sec)

如果想去除两侧引号，可以先做类型转换再做trim:

mysql> select trim(both '"' from cast(json_extract(field1, '$.t_value') as char)) from table1;
+----------------------------------------------------------------------------+
| trim(both '"' from cast(json_extract(field1, '$.t_value') as char)) |
+----------------------------------------------------------------------------+
| {\"id\":\"14\",\"timestamp\":1539768556,\"type\":1}                        |
+----------------------------------------------------------------------------+
1 row in set (0.00 sec)

如果要在MySQL中对解析后的json再进行解析，则需要加上json_unquote函数以去掉escape character：

mysql> select json_unquote(json_extract(field1, '$.t_value')) from table1;
+--------------------------------------------------------+
| json_unquote(json_extract(field1, '$.t_value')) |
+--------------------------------------------------------+
| {"id":"14","timestamp":1539768556,"type":1}            |
+--------------------------------------------------------+
1 row in set (0.00 sec)

如果要对解析过后的json继续解析，则在上一步基础上嵌套json_extract()

mysql> select json_extract(json_unquote(json_extract(field1, '$.t_value')), '$.timestamp') from table1;
+-------------------------------------------------------------------------------------+
| json_extract(json_unquote(json_extract(field1, '$.t_value')), '$.timestamp') |
+-------------------------------------------------------------------------------------+
| 1539768556                                                                          |
+-------------------------------------------------------------------------------------+
1 row in set (0.00 sec)

附

JSON_UNQUOTE() Special Character Escape Sequences

Escape Sequence	Character Represented by Sequence
\"	A double quote (") character
\b	A backspace character
\f	A formfeed character
\n	A newline (linefeed) character
\r	A carriage return character
\t	A tab character
\\	A backslash () character
\uXXXX	UTF-8 bytes for Unicode value XXXX

注

json_extract的等效操作符是->;
json_unquote(json_extract())的等效操作符是->>;

参考资料1
参考资料2
参考资料3

MySQL 嵌套JSON解析相关推荐

多层嵌套json解析
多层嵌套json解析-- com.jayway.jsonpath.JsonPath public class FormDefineHelper {private FormDefineHelper() ...
Hive中解析Json字段、json日志分析所用到的嵌套json解析
首先在百度搜索,json格式解析,将这段话变个格式看起来舒服. 然后,通过通过嵌套使用json函数解决.大概就是将内层的json字段当作一个整体,然后先将这个外层作为解析.在通过子查询使用方法,在外套 ...
python解析多层嵌套json_Python爬虫解析多个嵌套JSON,多级,json
Python爬虫解析多级嵌套json 最近刚接触Python爬虫,正好最近肺炎在全国蔓延,所以准备从网站爬取肺炎实时数据,并解析自己想要的数据.获取json数据网址为 https://m.look.3 ...
android的json数据解析,Android数据解析-JSON解析
JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式,基于JavaScript(Standard ECMA-262 3rd Edition - December ...
java解析多层嵌套json字符串
java解析多层嵌套json字符串 java分别解析下面两个json字符串 package jansonDemo;import com.alibaba.fastjson.JSON; import co ...
Json解析(Json集合,Json嵌套)
导入maven依赖: <dependency><groupId>net.sf.json-lib</groupId><artifactId>json-li ...
mysql json_extract用法,【MySQL】json_extract解析json
MySQL5.7 json串如下: {"Data":{"List":[{"ID":"101010","NAME ...
Flink CDC mongoDB 使用及Flink sql解析monggo中复杂嵌套JSON数据实现
需要实时采集MongoDB中的数据,所以考虑使用flink cdc mongodb,在flink cdc2.1版本后也支持了MongoDB的数据采集,是通过oplog. MongoDB中的存储数据的文 ...
java 解析Json对象（嵌套json数组）
在这里我需要读取的是json数据中promote的img的url,name,shopPrice. 1.实体类 2.工具类Moblie_Utils根据url获取网络json格式数据 public c ...