update

def update[From: Schema](tableName: String)(primaryKeyExpr: KeyConditionExpr.PrimaryKeyExpr[From])(
    action: Action[From]
): DynamoDBQuery[From, Option[From]]  = ???

The update operation is used to modify an existing item in a table. Both KeyConditionExpr.PrimaryKeyExpr and the Action params can be created using the ProjectionExpression's in the companion object for model class:

for {
  _ <- DynamoDBQuery.update("person")(Person.id.primaryKey === "1")(
    Person.name.set(42) + Person.age.set(42)
  ).execute
} yield maybePerson

update expressions

action	description
+	combines update actions eg Person.name.set(42) + Person.age.set(42)
set	Set an attribute Person.name.set("John")
setIfNotExists	Set attribute if it does not exists Person.name.setIfNotExists("John")
appendList	Add supplied list to the end of this list attribute
prepend	Prepend an element to a list attribute
prependList	Prepend a list to list attribute
deleteFromSet	delete all elements that match the supplied set
add(a: To)	adds this value as a number attribute if it does not exists, else adds the numeric value to the existing attribute
addSet	Adds this set as an attribute if it does not exists, else if it exists it adds the elements of the set
remove(index: Int)	remove an element at the specified index
remove	Removes this path expression from an item

See AWS API Reference to learn more about update expressions.

update query operations

<UPDATE_QUERY>
  .returns(<ReturnValues>) // ReturnValues.AllNew | ReturnValues.AllOld | ReturnValues.None <default>
  .where(<ConditionExpression>)