Cannot convert JSON number to number

[andremarianiello]

With MySQL

mysql> select JSON_EXTRACT('{"id":234}', '$.id')-1;
+--------------------------------------+
| JSON_EXTRACT('{"id":234}', '$.id')-1 |
+--------------------------------------+
|                                  233 |
+--------------------------------------+
1 row in set (0.00 sec)

mysql> select JSON_EXTRACT('{"id":234}', '$.id') = 234;
+------------------------------------------+
| JSON_EXTRACT('{"id":234}', '$.id') = 234 |
+------------------------------------------+
|                                        1 |
+------------------------------------------+
1 row in set (0.00 sec)

With go-mysql-server

MySQL [(none)]> select JSON_EXTRACT('{"id":234}', '$.id')-1;
ERROR 1105 (HY000): unable to cast sql.JSONDocument{Val:234} of type sql.JSONDocument to float64
MySQL [(none)]> select JSON_EXTRACT('{"id":234}', '$.id') = 234;
+------------------------------------------+
| JSON_EXTRACT('{"id":234}', '$.id') = 234 |
+------------------------------------------+
|                                        0 |
+------------------------------------------+
1 row in set (0.002 sec)```

[zachmu]

fixed by #503