No valid nullable type for PgVector

[rob2244]

Version

1.26.0

What happened?

When using sqlc.narg with a PgVector parameter a regular PgVector is returned. This causes a bug as you can't pass nil or an empty array to PgVector, you get the following error from postgres: "vector must have at least 1 dimension" see the related c code:

https://github.com/pgvector/pgvector/blob/master/src/vector.c

I'm not sure if this is a bug that should be fixed here, or upstream in the pg vector golang library.

Relevant log output

No response

Database schema

CREATE TABLE IF NOT EXISTS client_portal.public.glossary (
    id SERIAL primary key,
    org_id uuid NOT NULL,
    user_id uuid NOT NULL,
    term varchar NOT NULL,
    definition varchar NOT NULL,
    tags varchar,
    term_embedding vector(1024),
    tags_query tsquery,
    created_date timestamp DEFAULT (now() at time zone 'utc'),
    updated_date timestamp DEFAULT (now() at time zone 'utc'),
    UNIQUE(org_id, user_id, term)
);

SQL queries

-- name: InsertGlossaryEntry :one
INSERT INTO glossary (
    org_id,
    user_id,
    term,
    term_embedding,
    definition,
    tags,
    tags_query)
VALUES ($1, $2, $3, $4, $5, $6, to_tsquery('english', $7))
RETURNING id;

Configuration

version: "2"
sql:
  - engine: "postgresql"
    queries: "/pkg/dal/queries/"
    schema: "migrations/"
    gen:
      go:
        package: "dal"
        out: "pkg/dal/sqlc"
        sql_package: "pgx/v5"

Playground URL

https://play.sqlc.dev/p/810eb3df11f9df1f0b3fe5d41a9402bd8421ee3def68f49f45c27402331bbe2f

What operating system are you using?

Linux

What database engines are you using?

PostgreSQL

What type of code are you generating?

Go

[onestardao]

Looks like ProblemMap No.4 — PgVector nullable type mis-handling during schema → client code generation.
The current pipeline treats vector as non-nullable, so an empty or NULL PgVector fails the type check before it even reaches the query layer. That’s why you can’t pass an empty vector param without triggering a “no valid nullable type” error.

In my MIT-licensed framework (publicly starred by the Tesseract.js author), we handle this by adding a symbolic null-vector sentinel at the binding layer. It ensures the generated client code maps null → an explicit zero-length vector token, keeping PgVector happy without patching its core.

If you want the exact patch and reproducible test harness, DM me.