how to migrate my custom objects

[TuranTimur]

Hi.

I've created one custom objects, and am using it.
But if there is any change necessary, can I migrate to the other custom objects?

For example,

• My custom object A has 3 fields, a, b, c (string)
• but I needed to change its fields to a, b, d (integer)
• A and B shares same fields a, b but have a different field c, d
• I want to migrate data from custom object A to B

One of the possible way I can think of is

1. downloading my custom object A as a json
2. and I fix the data type and field name,
3. and then upload it to the custom object B

Please let me know if if there is anyway to migrate (does not need to be migration by json file, and that is just my thought)