ON DUPLICATE KEY UPDATE hack

gistfile1.py

from sqlalchemy.ext.compiler import compiles
from sqlalchemy.sql.expression import Insert

@compiles(Insert)
def append_string(insert, compiler, **kw):
    s = compiler.visit_insert(insert, **kw)
    if 'append_string' in insert.kwargs:
        return s + " " + insert.kwargs['append_string']
    return s


my_connection.execute(my_table.insert(append_string = 'ON DUPLICATE KEY UPDATE foo=foo'), my_values)

All the method above can't work.

@compiles(Insert, 'mysql')
def mysql_upsert(insert, compiler, **kw):
    def _gen_fv_dict(fv_dict):
        pass

    s = compiler.visit_insert(insert, **kw)
    if 'on_duplicate_key_update' in insert.kwargs:
        return s + ' ON DUPLICATE KEY UPDATE ' + _gen_fv_dict(insert.kwargs['on_duplicate_key_update'])
    return s

Insert.argument_for("mysql", "mysql_upsert", None)

 stmt = User.__table__.insert(on_duplicate_key_update={
        'age': 'age + VALUES(age)',
    })

session.execute(stmt, data)

And get error

SAWarning: Can't validate argument 'on_duplicate_key_update'; can't locate any SQLAlchemy dialect named 'on'
  % (k, dialect_name)

sqlalchemy.exc.IntegrityError: (_mysql_exceptions.IntegrityError) (1062, "Duplicate entry 'bulko11' for key 'name'")
[SQL: INSERT INTO user (name, age) VALUES (%s, %s)]
[parameters: ('bulko11', 11)]