MariaDB 从 JSON 文档中提取带有转义字符的值

Question

I am using the json_value function to extract values from a json document passed to a Mariadb database. When the document contains name/value pairs with escaped values such as "Item_Name":"60\" Table" the function only extracts 60 and returns null values for the rest of the name/value pairs in the document. Here is an example

Set @json = '{"Item_Name":"60\" Table", "Item_ID":"1"}';

select json_value(@json,'$.Item_Name') as Item_Name
, json_value(@json,'$.Item_ID') as ID

The results of this query is:

Item_Name	ID
60	null

Not sure how to extract the value with the escaped character.

Answer 1

I posted this question in the Mariadb Community as well and recieved an answer there. The trick is to add an additional escape character. Ian Gilfillan provided the answer in the Mariadb Community and his response is linked below.

https://mariadb.com/kb/en/extract-values-with-escaped-characters-from-json-document/+comments/5799#comment_5799

Quote:

You need to use two escape characters. A single escape would be applied by the SQL parser, but you want to pass the escaped string down. So:

Set @json = '{"Item_Name":"60\\" Table", "Item_ID":"1"}';

select json_value(@json,'$.Item_Name') as Item_Name ,
json_value(@json,'$.Item_ID') as ID;

+-----------+------+
| Item_Name | ID   |
+-----------+------+
| 60" Table | 1    |
+-----------+------+