Function insert_or_update_map 

pub fn insert_or_update_map(
    table: &str,
    columns_ans_values: &[(&str, &dyn ToKind)],
) -> Mutation

insert_or_update returns a Mutation to insert a row into a table. If the row already exists, it updates it instead. Any column values not explicitly written are preserved.

For a similar example, See update.