René's URL Explorer Experiment

Title: SQLModel SQLAlchemy ArgumentError when using HalfVector instead of Vector · Issue #142 · pgvector/pgvector-python · GitHub

Open Graph Title: SQLModel SQLAlchemy ArgumentError when using HalfVector instead of Vector · Issue #142 · pgvector/pgvector-python

X Title: SQLModel SQLAlchemy ArgumentError when using HalfVector instead of Vector · Issue #142 · pgvector/pgvector-python

Description: Hi, using a simple model like from sqlalchemy import SQLModel from pgvector.sqlalchemy import HalfVector class Item(SQLModel, table=True): embedding: Any = Field(sa_type=HalfVector((3072,))) Results in a sqlalchemy.exc.ArgumentError: 'Sc...

Open Graph Description: Hi, using a simple model like from sqlalchemy import SQLModel from pgvector.sqlalchemy import HalfVector class Item(SQLModel, table=True): embedding: Any = Field(sa_type=HalfVector((3072,))) Result...

X Description: Hi, using a simple model like from sqlalchemy import SQLModel from pgvector.sqlalchemy import HalfVector class Item(SQLModel, table=True): embedding: Any = Field(sa_type=HalfVector((3072,))) Result...

Opengraph URL: https://github.com/pgvector/pgvector-python/issues/142

X: @github

direct link

Domain: patch-diff.githubusercontent.com

{"@context":"https://schema.org","@type":"DiscussionForumPosting","headline":"SQLModel SQLAlchemy ArgumentError when using HalfVector instead of Vector","articleBody":"Hi, using a simple model like\n\n```python\nfrom sqlalchemy import SQLModel\nfrom pgvector.sqlalchemy import HalfVector\n\nclass Item(SQLModel, table=True):\n    embedding: Any = Field(sa_type=HalfVector((3072,)))\n```\n\nResults in a `sqlalchemy.exc.ArgumentError: 'SchemaItem' object, such as a 'Column' or a 'Constraint' expected, got HalfVector([3072.0])` when attempting to load it. Using `Vector` instead works fine.\n\nThe difference seems to be that `Vector` is an alias for `VECTOR`, which derives from `sqlalchemy.types.UserDefinedTypes`, whereas `HalfVector` is distinct from `HALFVEC`. Using `HALFVEC` instead appears to work.\n\nIt appears to be the same situation for `SparseVector`.","author":{"url":"https://github.com/fkarg","@type":"Person","name":"fkarg"},"datePublished":"2025-08-24T15:20:31.000Z","interactionStatistic":{"@type":"InteractionCounter","interactionType":"https://schema.org/CommentAction","userInteractionCount":2},"url":"https://github.com/142/pgvector-python/issues/142"}

Links:

Viewport: width=device-width