Updating a User

db.updateUser(username, update, writeConcern)

username indicates the username to be updated.
update is a document containing the replacement data for the user.
writeConcern: The write concern level of the update operation. This parameter is optional.

db.updateUser(
   "<username>",
   {
     customData : { <any information> },
     roles : [
       { role: "<role>", db: "<database>" } | "<role>",
       ...
     ],
     pwd: passwordPrompt(),      // Or  "<cleartext password>"
     authenticationRestrictions: [
        {
          clientSource: ["<IP>" | "<CIDR range>", ...],
          serverAddress: ["<IP>", | "<CIDR range>", ...]
        },
        ...
     ],
     mechanisms: [ "<SCRAM-SHA-1|SCRAM-SHA-256>", ... ],
     passwordDigestor: "<server|client>"
   },
   writeConcern: { <write concern> }
)

**Table 1** update description
Field	Type	Description
customData	Documents	Optional. Any information.
roles	Array	Optional. The role assigned to the user. An update to the roles array overrides the previous array's values.
pwd	string	Optional. The user's password.
authenticationRestrictions	Array	Optional. The IP address or CIDR blocks that can be accessed by a role.
mechanisms	Array	Optional. The specific SCRAM mechanism or mechanisms for the user credentials. Valid values are SCRAM-SHA-1 and SCRAM-SHA-256.
passwordDigestor	string	Optional. Whether to verify the password on the server or client. The default value is server.