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How to add BIT(1) data type to field? #298
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@dragonballa All the type mappings to the DB are hard coded right now and for the moment seem to be fairly limited.
https://github.com/tiangolo/sqlmodel/blob/7fcd4fd7c5661d2621e89ebf3a87059ac91ea6d2/sqlmodel/main.py#L378-L417It should be possible to extend this method and add extra mappings to the column types you need assuming SQLAlchemy supports them.
Reacted by dragonballa, Toni Alatalo, SH and mrh1997@oldfielj-ansto how do i import this so I can access the other fields from here? do i do
from typing import datetime, datefor instance?if i want to add a VARCHAR type
how would I do this? i really need some assistance with this as it is basically a deal breaker for me to use SQLModel in my project or not. Really want to use this but this data type extension part im not familiar with.
if issubclass(field.type_, varchar): return varcharIf your bit is a boolean, you can use that SQLAlchemy type in a field declaration, https://docs.sqlalchemy.org/en/14/core/type_basics.html#sqlalchemy.types.Boolean
from sqlalchemy import Column, String from sqlmodel import Field (...) code: bool = Field(sa_column=Column(Boolean))
Not tested but should be like that - this is an actual thing we use to declare a pg string array
from sqlalchemy import Column, String from sqlalchemy.dialects import postgresql #ARRAY contains requires dialect specific type from sqlmodel import Field (...) tags: Optional[Set[str]] = Field(default=None, sa_column=Column(postgresql.ARRAY(String())))
@dragonballa SQLModel is built to be as generic as possible to ensure compatibility with a wide array of database flavors, but as @antont points out you can add a specific column type override and a better supported way of doing this would be to use a boolean.
Accessing an existing database schema does complicate things a little, but a solution like the following should work.
from sqlmodel import Field, SQLModel from sqlalchemy import Column from sqlalchemy.dialects import mysql from datetime import datetime class Test(SQLModel, table=True): text: str = Field(title="Text") code: int = Field(title="Code", ge=0, le=1, sa_column=Column("code", mysql.BIT(1))) date: datetime = Field(title="Date")I don't have a MySQL database handy to test the behavior here, but I can tell you that by default SQLModel picks VARCHAR as the column type for PostgreSQL databases, so you might not need to override the column type, but if for some reason you needed to be explicit, something like this should work.
from sqlmodel import Field, SQLModel from sqlalchemy import Column from sqlalchemy.dialects import mysql from datetime import datetime class Test(SQLModel, table=True): text: str = Field(title="Text", sa_column=Column("text", mysql.VARCHAR())) code: int = Field(title="Code", ge=0, le=1, sa_column=Column("code", mysql.BIT(1))) date: datetime = Field(title="Date")Also bear in mind that applying this sort of patch would mean your code would only work on MySQL databases and would need to be modified if you decided to switch to another database software such as PostgreSQL.
Another thing worth noting here is that passing sa_column will mean the "primary_key", "index" and similar parameters on your field definition will not work, so if you need to pass them you'll have to manually specify them in your column definition.
from sqlmodel import Field, SQLModel from sqlalchemy import Column from sqlalchemy.dialects import mysql from datetime import datetime class Test(SQLModel, table=True): text: str = Field(title="Text") code: int = Field(title="Code", ge=0, le=1, sa_column=Column( "code", mysql.BIT(1), primary_key=True, index=True, )) date: datetime = Field(title="Date")My suggestion would be to install MySQL locally on your machine and start playing around creating new databases from your SQLModel's and see what column types you get, as SQLModel heavily relies on SQLAlchemy in this area.
Sorry I can't give you anything more concrete, but I primarily work with PostgreSQL these days.
Reacted by Gibson Wasukira- locked and limited conversation to collaborators
on Aug 11, 2025
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First of all I don't know exactly what are all the available types are so I looked at the sqlalchemy import statements over at https://github.com/tiangolo/sqlmodel/blob/7fcd4fd7c5661d2621e89ebf3a87059ac91ea6d2/sqlmodel/__init__.py
However I do not see an equivalent for MySQL's
BIT(1)so what can I do here? I am trying to connect to an existing MySQL table and it has a data type asBIT(1)which when I google it seems to be a Boolean? orTINYINTJust not clear to me how I can make SQLModel work with this table containing
BIT(1)as data type.Operating System
Linux
Operating System Details
No response
SQLModel Version
0.0.6
Python Version
3.8
Additional Context
No response