插入到json列时出错，而文档在mysql 5.7中包含一个json_string作为值

Question

always get a error when insert into json column when the json document contains a json string as value

msyql 5.7.25-0ubuntu0.18.04.2

sql with error:

INSERT INTO test VALUES(null, '{"a":"avalues","b":"{\"a\":\"avalues\"}"}');

but the sql below run well

INSERT INTO test VALUES(null, '{"a":"avalues","b":"{\'a\':\'avalues\'}"}');

Answer 1

You have to be careful escaping single quotes. But you do not need the \\" in the first query

Answer 2

To insert a literal backslash in a string, you need to use \\\\ .

I got this to work on 5.7:

INSERT INTO test VALUES(null, '{"a":"avalues","b":"{\\"a\\":\\"avalues\\"}"}');

I queried the data and got this output:

select json_pretty(data) from test;
+----------------------------------------------------+
| json_pretty(data)                                  |
+----------------------------------------------------+
| {
  "a": "avalues",
  "b": "{\"a\":\"avalues\"}"
} |
+----------------------------------------------------+
1 row in set (0.01 sec)

I don't know why you are storing a JSON string inside a JSON document. That's too error-prone to be a good idea.