SQLAlchemy update if unique key exists

From version 1.2 SQLAlchemy will support on_duplicate_key_update for MySQL

There is also examples of how to use it:

from sqlalchemy.dialects.mysql import insert

insert_stmt = insert(my_table).values(
    id='some_existing_id',
    data="inserted value")

on_duplicate_key_stmt = insert_stmt.on_duplicate_key_update(
    data=insert_stmt.values.data,
    status="U"
)

conn.execute(on_duplicate_key_stmt)

From version 1.1 SQLAlchemy support on_conflict_do_update for PostgreSQL

Examples:

from sqlalchemy.dialects.postgresql import insert

insert_stmt = insert(my_table).values(
    id='some_existing_id',
    data="inserted value")

do_update_stmt = insert_stmt.on_conflict_do_update(
    constraint="pk_my_table",
    set_=dict(data="updated value")
)

conn.execute(do_update_stmt)