SQLAlchemy HiLo PK Generator

There are two flavors of the HiLo generator, HiLoGenerator and RowPerTableHiLoGenerator. HiLoGenerator will create a single column table to keep track of the hi value:

CREATE TABLE single_hilo (
    next_hi BIGINT NOT NULL
)

RowPerTableHiLoGenerator will create a two column table to keep track of the hi value per table per row:

CREATE TABLE row_per_table_hilo (
        table_name VARCHAR(255) NOT NULL,
        next_hi BIGINT NOT NULL,
        PRIMARY KEY (table_name)
)

You can use them in your models like any other Sequence:

class Entity(Base):

    id = Column(BigInteger(), HiLoGenerator(), primary_key=True)
    ...

or

class Entity(Base):

    id = Column(BigInteger(), RowPerTableHiLoGenerator(), primary_key=True)
    ...