JSON_ARRAY_APPEND not inserting json document in MySQL

Question

I have started using MySQL 8 and trying to insert JSON data type in a mysql table

My table t1 looks as below:

# id    type  jval
1100000 type1

I want to insert value for jval which is of type JSON.

UPDATE t1 mdata
        SET mdata.jval = JSON_ARRAY_APPEND(jval, '$', JSON_OBJECT('user', 'user1', 'dept', 'dept1'))
        WHERE mdata.type = 'type1';

The above query is not inserting value for jval.

My table entry should look like below:

# id    type   jval
1100000 type1  [{"user": "user1", "dept": "dept1"}] 

Answer 1

UPDATE t1 mdata
        SET mdata.jval = JSON_ARRAY_APPEND('[]', '$', JSON_OBJECT('user', 'user1', 'dept', 'dept1'))
        WHERE mdata.type = 'type1';