It is possible to copy the contents of the Credentials collection into a new target database, along with the user documents. This means that passwords for users do not need to be reset.

The effect this migration will have on your end users would be this: Once you delete the original database, the user's token disappears and the user would need to be prompted to login in with their password. A new token would then be created and associated to the new database.

Step 1: Insert the users

Create( 
  Ref(Collection("customers"), "304590036497596609" ), 
  { 
    data: { 
    "userID": 1234, 
    "firstName": "Archibald", 
    "lastName": "Leech", 
    "address": { "street": "123 Elm", "city": "Iverness", "state": "CA", "zipCode": "94044" } } 
  } 
)

Step 2: Create user credentials

Update that user with the hashed password from the original source Credentials collection, or create a Credentials document directly.

Update(
  Ref(Collection("customers"), "304590036497596609" ),
  { 
    credentials: { hashed_password: "$2a$05$Dn6Kooyn0EQE7sBdtuKAb.Kf3OOu1r6Xvawi/lkJS6icUKlPSDmJa" } 
  }
)

// OR Alternatively

Create(
  Credentials(),
  {
    instance: Ref(Collection("customers"), "304590036497596609" ),
    hashed_password: "$2a$05$Dn6Kooyn0EQE7sBdtuKAb.Kf3OOu1r6Xvawi/lkJS6icUKlPSDmJa"
  }
)

NOTE: This must be done with a SERVER key. Admin key does not work.

Step 3: (Optional) verify the credential was created correctly

Paginate over the Credentials collection

 Paginate(Credentials()) 

{ data: [ Ref(Ref("credentials"), "305200181743190593") ] }

If you get the Credential documents, you can see the saved hashed_password.

Get( Ref(Ref("credentials"), "305200181743190593") ) 

{ ref: Ref(Ref("credentials"), "305200181743190593"), ts: 1627320424730000, 
hashed_password: "$2a$05$Dn6Kooyn0EQE7sBdtuKAb.Kf3OOu1r6Xvawi/lkJS6icUKlPSDmJa", 
instance: Ref(Collection("customers"), "304590036497596609") }

Step 4: Verify the original password authenticates the user correctly

Login(
  Ref(Collection("customers"), "304590036497596609"), 
  { password: "hasenpfeffer" }
) 

{ ref: Ref(Ref("tokens"), "305200271348204097"), ts: 1627320510180000,
instance: Ref(Collection("customers"), "304590036497596609"),
secret: "fnEEPEoHnxACQQPrh_MI0AYI21ClyPF4re3M6xHMAkmdxWrzTkw" }

Further Reading:

Security in Fauna

Credentials