UpdateOptions

options for Update operations.

JSON representation 
{
  "updateType": enum (UpdateType),
  "updateMask": string,
  "mergeFieldsOptions": {
    object (MergeFieldsOptions)
  }
}
Fields
updateType

enum (UpdateType)

type for update.
updateMask

string (FieldMask format)

Field mask for merging Document fields. For the FieldMask definition, see https://developers.google.com/protocol-buffers/docs/reference/google.protobuf#fieldmask

This is a comma-separated list of fully qualified names of fields. Example: "user.displayName,photo".
mergeFieldsOptions

object (MergeFieldsOptions)

options for merging.

UpdateType

Update type of the requests.

Enums
UPDATE_TYPE_UNSPECIFIED Defaults to full replace behavior, ie. FULL_REPLACE.
UPDATE_TYPE_REPLACE Fully replace all the fields (including previously linked raw document). Any field masks will be ignored.
UPDATE_TYPE_MERGE Merge the fields into the existing entities.
UPDATE_TYPE_INSERT_PROPERTIES_BY_NAMES Inserts the properties by names.
UPDATE_TYPE_REPLACE_PROPERTIES_BY_NAMES Replace the properties by names.
UPDATE_TYPE_DELETE_PROPERTIES_BY_NAMES Delete the properties by names.
UPDATE_TYPE_MERGE_AND_REPLACE_OR_INSERT_PROPERTIES_BY_NAMES For each of the property, replaces the property if the it exists, otherwise inserts a new property. And for the rest of the fields, merge them based on update mask and merge fields options.

MergeFieldsOptions

options for merging updated fields.

JSON representation 
{
  "replaceMessageFields": boolean,
  "replaceRepeatedFields": boolean
}
Fields
replaceMessageFields

boolean

When merging message fields, the default behavior is to merge the content of two message fields together. If you instead want to use the field from the source message to replace the corresponding field in the destination message, set this flag to true. When this flag is set, specified submessage fields that are missing in source will be cleared in destination.
replaceRepeatedFields

boolean

When merging repeated fields, the default behavior is to append entries from the source repeated field to the destination repeated field. If you instead want to keep only the entries from the source repeated field, set this flag to true.

If you want to replace a repeated field within a message field on the destination message, you must set both replaceRepeatedFields and replaceMessageFields to true, otherwise the repeated fields will be appended.