🐛 Fix setting nullable property of Fields that don't accept None

[van51]

Attempt to fix #76 where fields with default values would be considered nullable by sqlmodel, because they would be treated as not_required by Pydantic.

Previously

The following example code (copy-pasted from the issue)

from typing import Optional
from sqlmodel import SQLModel, Field, create_engine


class Test(SQLModel, table=True):
    id: Optional[int] = Field(default=None, primary_key=True)
    a: str
    b: Optional[str] = None
    c: str = Field(default="Hey")
    d: str = "hey"
    
sqlite_url = ""  # define a path here
engine = create_engine(sqlite_url, echo=True)
SQLModel.metadata.create_all(engine)

used to produce the following create table SQL command:

CREATE TABLE test (
	id INTEGER, 
	a VARCHAR NOT NULL, 
	b VARCHAR, 
	c VARCHAR, 
	d VARCHAR, 
	PRIMARY KEY (id)
)

Now

This PR produces:

CREATE TABLE test (
	id INTEGER NOT NULL, 
	a VARCHAR NOT NULL, 
	b VARCHAR, 
	c VARCHAR NOT NULL, 
	d VARCHAR NOT NULL, 
	PRIMARY KEY (id)
)

Please let me know what you think.

[Brobin]

@tiangolo can we get this pulled in? nullable=False is a sensible default, especially for primary keys. I believe this will also address #119

[r614]

^ I agree, I think this the query generated by this PR is more correct.

[codecov]

Codecov Report

Merging #79 (33daef3) into main (2407ecd) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##             main      #79   +/-   ##
=======================================
  Coverage   97.58%   97.59%           
=======================================
  Files         182      182           
  Lines        6054     6060    +6     
=======================================
+ Hits         5908     5914    +6     
  Misses        146      146           

Impacted Files	Coverage Δ
sqlmodel/main.py	83.91% <100.00%> (+0.28%)	⬆️
...orial/test_create_db_and_table/test_tutorial001.py	100.00% <100.00%> (ø)

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[github-actions]

📝 Docs preview for commit 2877c12 at: https://630a97760a0b955025267d1a--sqlmodel.netlify.app

[github-actions]

📝 Docs preview for commit 33daef3 at: https://630a97d81b8fa54cf7654d6b--sqlmodel.netlify.app

[tiangolo]

Awesome, thank you @van51! Great work! 🚀 🍰

And thanks @highflyingaction for the review and for spotting something to update! 🤓

---

Thanks everyone for the discussion. This will be available in the next version released in the next hours, SQLModel 0.0.7 🎉