Is there any way to assign default DbNull value to JSON column in MySQL?

Question

I'm using MySQL version '8.0.28' and I'm trying to assign a default value to JSON column to one table in MySQL workbench.

Have tried this Mysql set default value to a json type column but it didn't worked out.

Any pointers or help is welcomed.

Answer 1

If you want a NULL to be the default, you don't need to declare that. It's the "default default" so to speak.

Here are a few different ways, tested on MySQL 8.0.29.

mysql> create table mytable (id serial primary key, j json);
Query OK, 0 rows affected (0.01 sec)

mysql> insert into mytable () values ();
Query OK, 1 row affected (0.00 sec)

mysql> insert into mytable set j = null;
Query OK, 1 row affected (0.01 sec)

mysql> insert into mytable (id) values (default);
Query OK, 1 row affected (0.00 sec)

mysql> select * from mytable;
+----+------+
| id | j    |
+----+------+
|  1 | NULL |
|  2 | NULL |
|  3 | NULL |
+----+------+

You can't set a