Loopback 3 updating model properties ensure old data is converted correctly without data loss - loopbackjs

Question

So I am using Loopback 3 atm, and I am currently updating the properties of my model. Problem is that the structure will be different as before as certain properties are now split into 2 separate properties, thus if I would place it online that data might be lost due to those changes. (I am using mongodb)
Example original structure:
{
"properties": {
"address": {
"type": "string"
}
}
}
Example new structure:
{
"properties": {
"address": {
"type": {
"street": {
"type": "string"
},
"city": {
"type": "string"
},
"zipcode": {
"type": "string"
}
}
}
}
}
In my case there are also properties that change names instead of address its addressline or something like that.
I know that some of you might say that its better to move address to a separate model but this is just an example in my case im unable to move it to a separate table due to certain circumstances.
So my question is how can you update a model and remap the existing data to follow the new structure to ensure that the original data isn't lost.
Thanks in advance!

Answer 1

Here's my answer
I understand that loopback is database independent and my approach is going against that, nevertheless here's my approach.
We can write migration script based on the underlying db, this is what I tried for postgresdb
#1 For the scenario where data type is being changed.
ALTER TABLE dbname ADD COLUMN address2 jsonb;
UPDATE dbname set address2= to_json(address) ;
ALTER TABLE dbname DROP COLUMN address;
ALTER TABLE dbname RENAME COLUMN address2 TO address;
#2 and for the scenario where name needs to be changed
ALTER TABLE dbname ADD COLUMN addressline jsonb;
UPDATE dbname set addressline= address;
ALTER TABLE dbname DROP COLUMN address;
Hoping to find more and better answer for this question!!